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NIST Special Publication 800-37

Guide for the Security Certification and Accreditation of Federal

Information Systems

May 2004

February 2010

SP 800-37 is superseded in its entirety by the publication of

SP 800-37 Revision 1 (February 2010).

NIST Special Publication 800-37 Revision 1

Guide for Applying the Risk Management Framework to Federal

Information Systems: a Security Life Cycle Approach

Joint Task Force Transformation Initiative

February 2010 (Updated June 5, 2014)

http://dx.doi.org/10.6028/NIST.SP.800-37r1

Computer Security Division (Information Technology Lab)

SP 800-37 Revision 1 (as of June 19, 2015)

http://csrc.nist.gov/groups/SMA/fisma/Risk-Management-Framework

/

N/A
Guide for the Security 

Certification and Accreditation 

of Federal Information Systems

Ron Ross

Marianne Swanson 

Gary Stoneburner

Stu Katzke 

Arnold Johnson

 NIST Special Publication 800-37 

I N F O R M A T I O N S E C U R I T Y

Computer Security Division 

Information Technology Laboratory

National Institute of Standards and Technology

Gaithersburg, MD 20899-8930

May 2004

U.S. Department of Commerce

Donald L. Evans, Secretary 

Technology Administration

Phillip J. Bond, Under Secretary of Commerce for Technology 

National Institute of Standards and Technology

Arden L. Bement, Jr., Director 
Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

________________________________________________________________________________________________ 

Reports on Computer Systems Technology

The Information Technology Laboratory (ITL) at the National Institute of Standards and 

Technology (NIST) promotes the U.S. economy and public welfare by providing technical 

leadership for the Nation’s measurement and standards infrastructure. ITL develops tests, test 

methods, reference data, proof of concept implementations, and technical analyses to advance the 

development and productive use of information technology. ITL’s responsibilities include the 

development of management, administrative, technical, and physical standards and guidelines for 

the cost-effective security and privacy of other than national security-related information in 

federal information systems. The Special Publication 800-series reports on ITL’s research, 

guidelines, and outreach efforts in information system security, and its collaborative activities 

with industry, government, and academic organizations. 

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

________________________________________________________________________________________________ 

Authority

This document has been developed by the National Institute of Standards and Technology (NIST) 

in furtherance of its statutory responsibilities under the Federal Information Security Management 

Act (FISMA) of 2002, Public Law 107-347. 

NIST is responsible for developing standards and guidelines, including minimum requirements, 

for providing adequate information security for all agency operations and assets, but such 

standards and guidelines shall not apply to national security systems. This guideline is consistent 

with the requirements of the Office of Management and Budget (OMB) Circular A-130, Section 

8b(3), Securing Agency Information Systems, as analyzed in A-130, Appendix IV: Analysis of

Key Sections. Supplemental information is provided A-130, Appendix III. 

This guideline has been prepared for use by federal agencies. It may also be used by

nongovernmental organizations on a voluntary basis and is not subject to copyright. (Attribution 

would be appreciated by NIST.) 

Nothing in this document should be taken to contradict standards and guidelines made mandatory

and binding on federal agencies by the Secretary of Commerce under statutory authority. Nor

should these guidelines be interpreted as altering or superseding the existing authorities of the 

Secretary of Commerce, Director of the OMB, or any other federal official.

National Institute of Standards and Technology Special Publication 800-37, 64 pages 

(May 2004) CODEN: NSPUE2 

 

 

Certain commercial entities, equipment, or materials m ay be identified in this document in order to

describe an experimental procedure or concept adequately. Such identification is not intended to imply 

recommendation or endorsement by the National Institute of Standards and Technology, nor is it 

intended to imply that the entities, materials, or equipment are necessarily the best available for the 

purpose. 

There are references in this publication to documents currently under development by NIST in

accordance with responsibilities assigned to NIST under the Federal Information Security Management 

Act of 2002. These include: NIST Special Publication 800-53, NIST Special Publication 800-53A, and 

FIPS 200. The methodologies in this document may be used even before the completion of the 

aforementioned companion documents. Thus, until such time as each is document is completed, 

current requirements, guidelines and procedures (where they exist) remain operative. For planning and 

transition purposes, agencies may wish to closely follow the development of these new documents by

NIST. Individuals are also encouraged to review the public draft documents and offer their comments 

to NIST. 

COMMENTS MAY BE SUBMITTED TO THE COMPUTER SECURITY DIVISION, 

INFORMATION TECHNOLOGY LABORATORY, NIST, VIA ELECTRONIC MAIL AT SEC-CERT@NIST.GOV

OR VIA REGULAR MAIL AT

100 BUREAU DRIVE (MAIL STOP 8930) 

GAITHERSBURG, MD 20899-8930 

PAGE iii 
Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

________________________________________________________________________________________________ 

Acknowledgements 

The authors, Ron Ross, Marianne Swanson, Gary Stoneburner, Stu Katzke, and Arnold Johnson 

of the National Institute of Standards and Technology (NIST) wish to thank their colleagues who 

reviewed drafts of this document and contributed to its development. The authors also gratefully 

acknowledge and appreciate the many contributions from the public and private sectors whose 

thoughtful and constructive comments improved the quality and usefulness of this publication. 

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

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Table of Contents 

EXECUTIVE SUMMARY..........................................................................................................1

CHAPTER 1 INTRODUCTION.................................................................................................3

1.1 PURPOSE AND APPLICABILITY ................................................................................................. 5

1.2 SYSTEM DEVELOPMENT LIFE CYCLE ........................................................................................ 6

1.3 ORGANIZATION OF THIS SPECIAL PUBLICATION ......................................................................... 7

CHAPTER 2 THE FUNDAMENTALS ........................................................................................8

2.1 SECURITY CERTIFICATION AND ACCREDITATION ....................................................................... 8

2.2 ROLES AND RESPONSIBILITIES .............................................................................................. 12

2.3 ACCREDITATION BOUNDARIES............................................................................................... 16

2.4 COMMON SECURITY CONTROLS............................................................................................. 19

2.5 ACCREDITATION DECISIONS .................................................................................................. 19

2.6 SUPPORTING DOCUMENTATION ............................................................................................. 21

2.7 CONTINUOUS MONITORING ................................................................................................... 23

CHAPTER 3 THE PROCESS ................................................................................................25

3.1 INITIATION PHASE................................................................................................................. 26

3.2 SECURITY CERTIFICATION PHASE .......................................................................................... 35

3.3 SECURITY ACCREDITATION PHASE......................................................................................... 40

3.4 CONTINOUS MONITORING PHASE........................................................................................... 43

APPENDIX A REFERENCES................................................................................................48

APPENDIX B GLOSSARY....................................................................................................50

APPENDIX C ACRONYMS...................................................................................................58

APPENDIX D SUMMARY OF PHASES AND RESPONSIBILITIES ................................................59

APPENDIX E SAMPLE TRANSMITTAL AND DECISION LETTERS...............................................61

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

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EXECUTIVE SUMMARY

he purpose of this publication is to provide guidelines for the security certification and 

accreditation of information systems supporting the executive agencies of the federal 

government. The guidelines have been developed to help achieve more secure information T

systems within the federal government by: 

• Enabling more consistent, comparable, and repeatable assessments of security controls in 

federal information systems; 

• Promoting a better understanding of agency-related mission risks resulting from the operation 

of information systems; and 

• Creating more complete, reliable, and trustworthy information for authorizing officials—to 

facilitate more informed security accreditation decisions. 

Security certification and accreditation are important activities that support a risk management 

process and are an integral part of an agency’s information security program.

Security accreditation is the official management decision given by a senior agency official to 

authorize operation of an information system and to explicitly accept the risk to agency

operations, agency assets, or individuals based on the implementation of an agreed-upon set of 

security controls. Required by OMB Circular A-130, Appendix III, security accreditation 

provides a form of quality control and challenges managers and technical staffs at all levels to 

implement the most effective security controls possible in an information system, given mission 

requirements, technical constraints, operational constraints, and cost/schedule constraints. By 

accrediting an information system, an agency official accepts responsibility for the security of the 

system and is fully accountable for any adverse impacts to the agency if a breach of security

occurs. Thus, responsibility and accountability are core principles that characterize security

accreditation. 

It is essential that agency officials have the most complete, accurate, and trustworthy information 

possible on the security status of their information systems in order to make timely, credible, riskbased decisions on whether to authorize operation of those systems. The information and 

supporting evidence needed for security accreditation is developed during a detailed security

review of an information system, typically referred to as security certification. Security

certification is a comprehensive assessment of the management, operational, and technical 

security controlsin an information system, made in support of security accreditation, to determine 

the extent to which the controls are implemented correctly, operating as intended, and producing 

the desired outcome with respect to meeting the security requirements for the system. The results 

of a security certification are used to reassess the risks and update the system security plan, thus 

providing the factual basis for an authorizing official to render a security accreditation decision. 

The security certification and accreditation process consists of four distinct phases: 

• Initiation Phase; 

• Security Certification Phase; 

• Security Accreditation Phase; and 

• Continuous Monitoring Phase. 

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

________________________________________________________________________________________________ 

Each phase in the security certification and accreditation process consists of a set of well-defined 

tasks and subtasks that are to be carried out, as indicated, by responsible individuals (e.g., the 

Chief Information Officer, authorizing official, authorizing official’s designated representative,

senior agency information security officer, information system owner, information owner, 

information system security officer, certification agent, and user representatives).

The Initiation Phase consists of three tasks: (i) preparation; (ii) notification and resource 

identification; and (iii) system security plan analysis, update, and acceptance. The purpose of this 

phase is to ensure that the authorizing official and senior agency information security officer are 

in agreement with the contents of the system security plan, including the system’s documented

security requirements, before the certification agent begins the assessment of the security controls 

in the information system. 

The Security Certification Phase consists of two tasks: (i) security control assessment; and (ii) 

security certification documentation. The purpose of this phase is to determine the extent to 

which the security controls in the information system are implemented correctly, operating as 

intended, and producing the desired outcome with respect to meeting the security requirements 

for the system. This phase also addresses specific actions taken or planned to correct deficiencies 

in the security controls and to reduce or eliminate known vulnerabilities in the information 

system. Upon successful completion of this phase, the authorizing official will have the 

information needed from the security certification to determine the risk to agency operations, 

agency assets, or individuals—and thus, will be able to render an appropriate security 

accreditation decision for the information system. 

The Security Accreditation Phase consists of two tasks: (i) security accreditation decision; and 

(ii) security accreditation documentation. The purpose of this phase is to determine if the 

remaining known vulnerabilities in the information system (after the implementation of an 

agreed-upon set of security controls) pose an acceptable level of risk to agency operations, 

agency assets, or individuals. Upon successful completion of this phase, the information system

owner will have: (i) authorization to operate the information system; (ii) an interim authorization 

to operate the information system under specific terms and conditions; or (iii) denial of 

authorization to operate the information system. 

The Continuous Monitoring Phase consists of three tasks: (i) configuration management and 

control; (ii) security control monitoring; and (iii) status reporting and documentation. The 

purpose of this phase is to provide oversight and monitoring of the security controls in the 

information system on an ongoing basis and to inform the authorizing official when changes 

occur that may impact on the security of the system. The activities in this phase are performed 

continuously throughout the life cycle of the information system. 

Completing a security accreditation ensures that an information system will be operated with 

appropriate management review, that there is ongoing monitoring of security controls, and that 

reaccreditation occurs periodically in accordance with federal or agency policy and whenever 

there is a significant change to the system or its operational environment. 

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

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CHAPTER ONE

INTRODUCTION

THE NEED FOR SECURITY CERTIFICATION AND ACCREDITATION 

he E-Government Act (Public Law 107-347) passed by the one hundred and seventh 

Congress and signed into law by the President in December 2002 recognized the 

importance of information security1

 to the economic and national security interests of the 

United States. Title III of the E-Government Act, entitled the Federal Information Security

Management Act (FISMA), requires each federal agency to develop, document, and implement 

an agency-wide information security program to provide information security for the information 

and information systems2

 that support the operations3 and assets of the agency, including those 

provided or managed by another agency, contractor, or other source. The information security 

program must include: 

T

• Periodic assessments of risk, including the magnitude of harm that could result from the 

unauthorized access, use, disclosure, disruption, modification, or destruction of information 

and information systems that support the operations and assets of the agency; 

• Policies and procedures that are based on risk assessments, cost-effectively reduce 

information security risks to an acceptable level, and ensure that information security is 

addressed throughout the life cycle of each agency information system; 

• Subordinate plans for providing adequate information security for networks, facilities, 

information systems, or groups of information systems, as appropriate; 

• Security awareness training to inform personnel (including contractors and other users of 

information systems that support the operations and assets of the agency) of the information 

security risks associated with their activities and their responsibilities in complying with 

agency policies and procedures designed to reduce these risks; 

• Periodic testing and evaluation of the effectiveness of information security policies, 

procedures, practices, and security controls4

 to be performed with a frequency depending on 

risk, but no less than annually; 

• A process for planning, implementing, evaluating, and documenting remedial actions to 

address any deficiencies in the information security policies, procedures, and practices of the 

agency; 

• Procedures for detecting, reporting, and responding to security incidents; and 

• Plans and procedures to ensure continuity of operations for information systems that support

the operations and assets of the agency. 

 

1 Information security is the protection of information and information systems from unauthorized access, use, 

disclosure, disruption, modification, or destruction in order to provide confidentiality, integrity, and availability. 

2

 An information system is a discrete set of information resources organized expressly for the collection, processing, 

maintenance, use, sharing, dissemination, or disposition of information.

3

 Agency operations include such things as mission, functions, image, and reputation. 

4

 Security controls are the management, operational, and technical controls (i.e., safeguards or countermeasures) 

prescribed for an information system to protect the confidentiality, integrity, and availability of the system and its

information. 

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

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FISMA, the Paperwork Reduction Act of 1995, and the Information Technology Management 

Reform Act of 1996 (Clinger-Cohen Act), explicitly emphasize a risk-based policy for costeffective security. In support of and reinforcing this legislation, the Office of Management and 

Budget (OMB) through Circular A-130, Appendix III, Security of Federal Automated 

Information Resources, requires executive agencies5

 within the federal government to: 

• Plan for security; 

• Ensure that appropriate officials are assigned security responsibility;

• Review the security controls in their information systems; and 

• Authorize system processing prior to operations and periodically thereafter. 

These management responsibilities presume that responsible agency officials understand the risks 

and other factors that could adversely affect their missions. Moreover, these officials must 

understand the current status of their security programs and the security controls planned or in

place to protect their information and information systems in order to make informed judgments 

and investments that appropriately mitigate risk to an acceptable level. The ultimate objective is 

to conduct the day-to-day operations of the agency and to accomplish the agency’s stated 

missions with what OMB Circular A-130, Appendix III, defines as adequate security, or security 

commensurate with risk, including the magnitude of harm resulting from the unauthorized access, 

use, disclosure, disruption, modification, or destruction of information. 

Security accreditation 6

 is the official management decision given by a senior agency official to 

authorize operation of an information system and to explicitly accept the risk to agency

operations, agency assets, or individuals7

 based on the implementation of an agreed-upon set of 

security controls. The senior agency official should have the authority to oversee the budget and 

business operations of the information system. Required by OMB Circular A-130, Appendix III, 

security accreditation provides a form of quality control and challenges managers and technical 

staffs at all levels to implement the most effective security controls possible in an information 

system, given mission requirements, technical constraints, operational constraints, and 

cost/schedule constraints. By accrediting an information system, an agency official accepts 

responsibility for the security of the system and is fully accountable for any adverse impacts to 

the agency if a breach of security occurs. Thus, responsibility and accountability are core 

principles that characterize security accreditation. 

The assessment of risk and the development of system security plans are two important activities 

in an agency’s information security program that directly support security accreditation and are 

required by FISMA and OMB Circular A-130, Appendix III. Risk assessments influence the 

development of the security controls for information systems and generate much of the 

information needed for the associated system security plans. Risk assessments can be 

accomplished in a variety of ways depending on the specific needs of the agency. Some agencies 

may choose to assess risk informally. Other agencies may choose to employ a more formal and 

structured approach. In either case, the assessment of risk is a process that should be incorporated 

 

5

 An executive agency is: (i) an Executive Department specified in 5 U.S.C., Section 101; (ii) a Military Department

specified in 5 U.S.C., Section 102; (iii) an independent establishment as defined in 5 U.S.C., Section 104(1); and (iv) a 

wholly owned government corporation fully subject to the provisions of 31 U.S.C., Chapter 91. 

6

 Security accreditation is synonymous with security authorization; the terms are used interchangeably in this special

publication.

7Risks to individuals may include, but are not limited to, loss of the privacy to which individuals are entitled under law. 

PAGE 4 
Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

________________________________________________________________________________________________ 

into the system development life cycle. At a minimum, documentation should be produced that 

describes the process employed and the results obtained. System security plans provide an 

overview of the information security requirements and describe the security controls in place or 

planned for meeting those requirements. System security plans can include as references or 

attachments, other important security-related documents (e.g., risk assessments, contingency 

plans, incident response plans, security awareness and training plans, information system rules of 

behavior, configuration management plans, security configuration checklists, privacy impact 

assessments, system interconnection agreements) produced as part of an agency’s information

security program.

8

In addition to risk assessments and system security plans, security assessments play an important 

role in security accreditation. It is essential that agency officials have the most complete, 

accurate, and trustworthy information possible on the security status of their information systems 

in order to make timely, credible, risk-based decisions on whether to authorize operation of those 

systems. The information and supporting evidence needed for security accreditation is developed 

during a detailed security review of an information system, typically referred to as security

certification. Security certification is a comprehensive assessment of the management, 

operational, and technical security controls9

 in an information system, made in support of security

accreditation, to determine the extent to which the controls are implemented correctly, operating 

as intended, and producing the desired outcome with respect to meeting the security requirements 

for the system. The results of a security certification are used to reassess the risks and update the 

system security plan, thus providing the factual basis for an authorizing official to render a 

security accreditation decision. 

By accrediting an information system, an agency official accepts the risks associated with 

operating the system and the associated implications on agency operations, agency assets, or 

individuals. Completing a security accreditation ensures that an information system will be 

operated with appropriate management review, that there is ongoing monitoring of security

controls, and that reaccreditation occurs periodically in accordance with federal or agency policy

and whenever there is a significant change to the system or its operational environment.10

1.1 PURPOSE AND APPLICABILITY

The purpose of this publication is to provide guidelines for the security certification and 

accreditation of information systems supporting the executive agencies of the federal government. 

The guidelines have been developed to help achieve more secure information systems within the 

federal government by: 

 

8

 NIST Special Publications 800-18, 800-30, 800-34, 800-47, 800-50, 800-61, and 800-70 respectively, provide

guidance on system security plans, risk management and risk assessments, contingency planning, information system 

interconnections, security awareness and training, incident response planning, and security configuration checklists. 

9 Management controls are the safeguards or countermeasures that focus on the management of risk and the 

management of information system security. Operational controls are the safeguards or countermeasures that primarily

are implemented and executed by people (as opposed to systems). Technical controls are the safeguards or 

countermeasures that are primarily implemented and executed by the information system through mechanisms 

contained in the hardware, software, or firmware components of the system. 

10 Examples of significant changes to an information system that should be reviewed for possible reaccreditation

include but are not limited to: (i) installation of a new or upgraded operating system, middleware component, or

application; (ii) modifications to system ports, protocols, or services; (iii) installation of a new or upgraded hardware 

platform or firmware component; or (iv) modifications to cryptographic modules or services. Changes in laws, 

directives, policies, or regulations, while not always directly related to the information system, can also potentially

affect the security of the system and trigger a reaccreditation action. 

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

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• Enabling more consistent, comparable, and repeatable assessments of security controls in 

federal information systems; 

• Promoting a better understanding of agency-related mission risks resulting from the operation 

of information systems; and 

• Creating more complete, reliable, and trustworthy information for authorizing officials—to 

facilitate more informed security accreditation decisions. 

The guidelines provided in this special publication are applicable to all federal information 

systems other than those systems designated as national security systems as defined in 44 U.S.C., 

Section 3542.11 The guidelines have been broadly developed from a technical perspective so as 

to be complementary to similar guidelines for national security systems. This publication 

provides augmented, updated security certification and accreditation information to federal 

agencies and will functionally replace Federal Information Processing Standards (FIPS) 102, 

Guidelines for Computer Security Certification and Accreditation, September 1983, when it is

rescinded. State, local, and tribal governments, as well as private sector organizations comprising 

the critical infrastructure of the United States, are encouraged to consider the use of these 

guidelines, as appropriate. 

1.2 SYSTEM DEVELOPMENT LIFE CYCLE

All federal information systems, including operational systems, systems under development, and 

systems undergoing some form of modification or upgrade, are in some phase of what is 

commonly referred to as the system development life cycle.12 There are many activities occurring 

during the life cycle of an information system dealing with the issues of cost, schedule, and 

performance. In addition to the functional requirements levied on an information system, security 

requirements must also be considered. When fully implemented, the information system must be 

able to meet its functional requirements and do so in a manner that is secure enough to protect 

agency operations, agency assets, and individuals. 

In accordance with the provisions of FISMA, agencies are required to have an agency-wide 

information security program and that program should be effectively integrated into the system

development life cycle. For new information systems (or major upgrades to information 

systems), the security certification and accreditation tasks begin early in the system development 

life cycle during the initiation, development, and acquisition phases and are important in shaping 

and influencing the security capabilities of the system. For operational systems and older legacy

systems, the certification and accreditation tasks may, by necessity, begin later in the system

development life cycle during the operations and maintenance phase and be more costly to

implement. In either situation, all of the tasks should be completed to ensure that: 

• The information system has received the necessary attention with regard to security; and 

• The authorizing official explicitly accepts the risk to agency operations, agency assets, or 

individuals based on the implementation of an agreed-upon set of security controls. 

 

11 NIST Special Publication 800-59 provides guidance for identifying an information system as a national security

system.

12 There are typically five phases in the system development life cycle of an information system: (i) system initiation; 

(ii) system development and acquisition; (iii) system implementation; (iv) system operations and maintenance; and (v) 

system disposal. NIST Special Publication 800-64 provides guidance on the security considerations in the information 

system development life cycle. 

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1.3 ORGANIZATION OF THIS SPECIAL PUBLICATION

The remainder of this special publication is organized as follows: 

• Chapter 2 describes the fundamentals of security certification and accreditation and includes: 

(i) an agency-wide view on cost-effective implementation; (ii) the roles and responsibilities 

of key participants; (iii) the considerations for determining accreditation boundaries; (iv) an 

introduction to common security controls; (v) types of accreditation decisions; (vi) 

requirements for supporting documentation; and (vii) the need for continuous monitoring of 

security controls. 

• Chapter 3 provides an overview of the different phases of the security certification and 

accreditation process and includes: (i) a description of the associated tasks and subtasks in 

each phase; (ii) the responsibilities of various participants in each subtask; (iii) guidance to 

help explain how to execute each subtask; (iv) supplemental guidance for low-impact 

information systems; and (v) appropriate references to supporting policies, standards, and 

guidelines. 

• Supporting appendices provide more detailed security certification and accreditation-related 

information and include: (i) general references; (ii) definitions and terms; (iii) acronyms; (iv) 

summary of tasks and subtasks; and (v) sample accreditation transmittal and decision letters.

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

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CHAPTER TWO

THE FUNDAMENTALS

BASIC CONCEPTS ASSOCIATED WITH SECURITY CERTIFICATION AND ACCREDITATION 

he purpose of this chapter is to describe the fundamentals of security certification and 

accreditation to include: (i) agency-level activities that can promote more cost-effective 

certification and accreditation processes; (ii) roles and responsibilities of key participants; 

(iii) approaches for determining accreditation boundaries; (iv) partitioning of security controls to 

facilitate reuse of assessment results; (v) types of security accreditation decisions; (vi) necessary

documentation and supporting materials; and (vii) ongoing activities employed to monitor the 

effectiveness of security controls. 

T

2.1 SECURITY CERTIFICATION AND ACCREDITATION

While security certification and accreditation are very closely related, they are indeed very 

distinct activities. Security accreditation is about the acceptance and management of risk—the 

risk to agency operations, agency assets, or individuals that results from the operation of an 

information system. Authorizing officials must be able to determine the risk to operations, assets, 

or individuals and the acceptability of such risk given the mission or business needs of their 

agencies. Authorizing officials must weigh the appropriate factors and decide to either accept or 

reject the risk to their respective agencies. To ensure that authorizing officials make credible, 

risk-based decisions, the following questions must be answered during the security certification 

and accreditation process: 

• Does the potential risk to agency operations, agency assets, or individuals described in the 

system security plan (or risk assessment) prior to security certification appear to be correct, 

and if so, would this risk be acceptable?

• Are the security controls in the information system effective in achieving the desired level of 

protection as defined by the security requirements for the system?

• What specific actions have been taken or are planned to correct any deficiencies in the 

security controls for the information system and to reduce or eliminate known 

vulnerabilities—and have resources been allocated to accomplish those actions? 

• How do the results of security certification translate into actual agency-level risk and is this 

risk acceptable?

Security certification directly supports security accreditation by providing authorizing officials 

with important information necessary to make credible, risk-based decisions on whether to place 

information systems into operation or continue their current operation. This information is 

produced by assessing the security controls in the information system to determine the extent to 

which the controls are implemented correctly, operating as intended, and producing the desired 

outcome with respect to meeting the security requirements for the system. Security certification 

can include a variety of assessment methods (e.g., interviewing, inspecting, studying, testing, 

demonstrating, and analyzing) and associated assessment procedures depending on the depth and 

breadth of assessment required by the agency.

13

 

13 NIST Special Publication 800-53A provides guidance for assessing the security controls in an information system. 

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Special Publication 800-37 Guide for the Security Certification and Accreditation of Federal Information Systems 

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The determination as to whether the security controls selected are in fact adequate to meet the 

security requirements for the information system is made during the initiation phase of the system

development life cycle. It is in this phase of the life cycle that security requirements are 

established, security controls selected, and the authorizing official and senior agency information 

security officer approve the system security plan.14 For legacy information systems (i.e., systems 

that are currently in the operations and maintenance phase of the system development life cycle), 

the determination of security control adequacy is, once again, accomplished prior to security 

certification when the system security plan is approved. 

Security certification does not include the determination of risk to agency operations, agency

assets, or individuals. The determination of program-level or agency-level risk generally requires 

a broader, more strategic view of the agency than can be obtained from the more technically

focused, system-level view of the information system that results from security certification. 

Authorizing officials or their designated representatives are better positioned to make mission risk 

determinations based on the known vulnerabilities remaining in the information system after the 

implementation of an agreed-upon set of security controls. The ultimate decision on the 

acceptability of such risk is the responsibility of the authorizing official. Authorizing officials or 

their designated representatives may, when needed, consult other individuals within the agency

(e.g., senior agency information security officers, information system owners, information system

security officers, or certification agents), at any phase in the certification and accreditation 

process to obtain advice on the security of the information system. Figure 2.1 illustrates the 

relationship between information system vulnerabilities and program/agency-level, mission risk. 

Remaining 

vulnerabilities 

affecting 

operations, 

assets, or 

individuals 

MISSION RISK

Program/Agency-level View 

OPERATIONS, ASSETS, INDIVIDUALS

Remaining 

vulnerabilities 

affecting 

operations, 

assets, or 

individuals 

Local View 

- Security controls 

- System vulnerabilities

AGENCY

INFORMATION 

SYSTEM #3

Local View 

- Security controls 

- System vulnerabilities

AGENCY

INFORMATION 

SYSTEM #2

Local View 

- Security controls 

- System vulnerabilities

AGENCY

INFORMATION 

SYSTEM #1

FIGURE 2.1 INFORMATION SYSTEM VULNERABILITIES AND MISSION RISK

Security accreditation is part of a dynamic, ongoing risk management process. An information 

system is authorized for operation at a specific point in time reflecting the current security state of 

the system. The inevitable changes to the information system (including hardware, firmware, 

 

14 Security certification and accreditation activities should be closely linked to and be a part of the system development 

life cycle for the information system. This linkage and integration into the life cycle will ensure that important

security-related considerations are included in the design, development, implementation, and operation of the 

information system. 

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software and people) and the potential impact those changes may have on agency operations, 

agency assets, or individuals, require a structured and disciplined process capable of monitoring 

the effectiveness of the security controls in the information system on an ongoing basis. Thus, 

the initial security accreditation must be supplemented and reinforced by a continuous monitoring 

process that: (i) tracks the changes to the information system; (ii) analyzes the security impact of 

those changes; (iii) makes appropriate adjustments to the security controls and the system security 

plan; and (iv) reports the security status of the system to appropriate agency officials. The 

following questions should be answered during the continuous monitoring process: 

• Could any of the changes to the information system affect the current, identified 

vulnerabilities in the system or introduce new vulnerabilities into the system? 

• If so, would the resulting risk to agency operations, agency assets, or individuals be 

unacceptable?

• When will the information system need to be reaccredited in accordance with federal or 

agency policy?

The successful completion of the security certification and accreditation process provides agency 

officials with the necessary confidence that the information system has adequate security

controls, that any vulnerabilities in the system have been considered in the risk-based decision to 

authorize processing, and that appropriate plans and funds have been identified to correct any

deficiencies in the information system. 

An Agency-wide Perspective 

When considering the prospect of accrediting agency information systems, it is important to put 

these activities into perspective with respect to the agency’s mission and operational 

responsibilities. Employing more secure information systems is critical to the success of an 

agency in carrying out its mission and conducting its day-to-day functions. However, security is 

only one of many factors that must be considered by agency officials in the design, development, 

acquisition, operation, and maintenance of information systems. In the end, agencies must have

systems that provide a high degree of functionality and adequate security so as not to place their 

respective missions at unacceptable levels of risk. 

The increasing costs required to adequately protect agency information systems necessitates an

agency-wide view of security to make the costs more manageable.15 Agencies must consider their 

entire inventory of information systems when developing appropriate strategies and programs for 

protecting those systems and managing agency-level risks. The cost of accrediting large numbers 

of information systems with varying degrees of complexity is a critical issue facing agencies 

today. The solution to this problem can be found in part, by creating and maintaining an agencywide information security program that promotes the reuse and sharing of security control 

development, implementation, and assessment-related information including: 

• Employment of standardized security controls and methods for assessing those controls; 

• Development of standardized assessment plans, methods and procedures to be used in 

security certifications and accreditations;

• Adoption, specification, and promulgation of standardized policies, procedures, and 

documentation for common security program areas (e.g., rules of behavior, system

 

15 Some agencies may choose to establish an authorization advocate or security certification and authorization 

organization that manages, coordinates, and oversees all security authorization activities, agency-wide—working with 

the senior agency information security officer, authorizing officials, and information system owners. 

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administration, auditing, system monitoring, vulnerability scanning, management of user 

accounts, configuration management, incident response, contingency planning, and system

maintenance); 

• Refinement of policies, procedures, and documentation on a system-by-system basis, as 

needed, by preparing amendments or adding system-specific appendices; 

• Adoption, publication, and distribution (preferably in an online database) of agency

prescribed or developed security implementation guidance; 

• Establishment of a protected central repository, preferably online, for all certification and 

accreditation documentation, acquisition-related information, risk and vulnerability 

assessments, compliance surveys, security incident reporting and remediation results, external 

security audits, and making these easily accessible by appropriate agency personnel; and 

• Procurement of agency-wide licenses for automated tools such as vulnerability scanners, 

online security monitoring tools, audit reduction tools, and certification and accreditation 

support tools.

Since the cost of security certification and accreditation can be substantial, it is important to 

leverage the results of previous assessments and audits that have been conducted on an agency’s

information system or the particular components comprising that system. Several potential 

sources for consideration include: (i) commercial product testing and evaluation programs;16 (ii) 

privacy impact assessments; (iii) physical security assessments; (iv) self-assessments;17 and (v) 

internal and external audits.18 These assessments and audits can support the security certification 

and accreditation process in two important ways. First, the assessment and audit results can be

used to gauge the preparedness of an information system for security certification and 

accreditation by examining the status of key security controls in the system. Second, the results

produced during these assessments and audits can be considered and potentially reused, when 

appropriate, during the security certification and accreditation process.19 Bringing in assessment

and audit results from multiple sources that the security controls in an information system are 

implemented correctly, operating as intended, and producing the desired outcome with respect to 

meeting the security requirements for the system, not only reduces the potential cost of security 

certification and accreditation but also increases the overall confidence in the final results. 

Reuse and sharing of security control development, implementation, and assessment-related 

information can significantly reduce agency security costs in new acquisitions, certifications and 

 

16 Programs for the testing and evaluation of cryptographic modules and information technology products are available 

under the NIST Cryptographic Module Validation Program (CMVP) (http://csrc.nist.gov/cryptval), and National

Information Assurance Partnership (NIAP) Common Criteria Evaluation and Validation Scheme (CCEVS) 

(http://niap.nist.gov/cc-scheme), respectively, in accordance with federal and international security standards.

17 Self-assessments can be conducted using a variety of methodologies including the National Security Agency

INFOSEC Assessment Methodology (http://www.nsa.gov/isso) and NIST Special Publication 800-26, Security SelfAssessment Guide for Information Technology Systems (http://csrc.nist.gov/publications). 

18 The Office of the Inspector General typically conducts internal audits on federal agencies. The General Accounting 

Office conducts external audits on agency information systems using the Federal Information System Controls Audit 

Manual (http://www.gao.gov). 

19 Previous assessment and audit results should always be reviewed and/or analyzed to determine the extent to which 

those results are still applicable and accurately reflect the current security state of the information system. Where

previous results are deemed not fully applicable or less than current, those areas should be reassessed or the differences 

so noted for consideration in the final security assessment report.

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accreditations of similar information systems, and reaccreditations of existing systems—and can 

ultimately result in a more consistent application of security solutions, agency-wide. 

2.2 ROLES AND RESPONSIBILITIES

The following sections describe the roles and responsibilities of key participants involved in an

agency’s security certification and accreditation process.20 Recognizing that agencies have 

widely varying missions and organizational structures, there may be differences in naming 

conventions for certification and accreditation-related roles and how the associated 

responsibilities are allocated among agency personnel (e.g., multiple individuals filling a single 

role or one individual filling multiple roles21). However, the basic functions remain the same. 

The security certification and accreditation process described in this special publication is 

flexible, allowing agencies to effectively accomplish the intent of the specific tasks within their 

respective organizational structures to best manage the risks to agency operations, agency assets, 

or individuals. 

Chief Information Officer

The Chief Information Officer 22 is the agency official responsible for: (i) designating a senior 

agency information security officer; (ii) developing and maintaining information security

policies, procedures, and control techniques to address all applicable requirements; (iii) training 

and overseeing personnel with significant responsibilities for information security; (iv) assisting 

senior agency officials concerning their security responsibilities; and (v) in coordination with 

other senior agency officials, reporting annually to the agency head on the effectiveness of the 

agency information security program, including progress of remedial actions. The Chief 

Information Officer, with the support of the senior agency information security officer, works 

closely with authorizing officials and their designated representatives to ensure that an agencywide security program is effectively implemented, that the certifications and accreditations 

required across the agency are accomplished in a timely and cost-effective manner, and that there 

is centralized reporting of all security-related activities. 

To achieve a high degree of cost effectiveness with regard to security, the Chief Information 

Officer encourages the maximum reuse and sharing of security-related information including: (i) 

threat and vulnerability assessments; (ii) risk assessments; (iii) results from common security

control assessments; and (iv) any other general information that may be of assistance to 

information system owners and their supporting security staffs. In addition to the above duties, 

the Chief Information Officer and authorizing officials determine the appropriate allocation of 

resources dedicated to the protection of the agency’s information systems based on organizational 

priorities. In certain instances, the Chief Information Officer may be designated as the 

authorizing official for agency-wide general support systems or as a co-authorizing official with 

other senior officials for selected agency information systems. 

 

20 Agencies may define other significant roles (e.g., systems administrators, facilities managers, system security

engineers, and operations managers) to support the security certification and accreditation process. The Office of the 

Inspector General may also become involved and take on the role of independent auditor in assessing the quality of

security certification and accreditation processes.

21 Caution should be exercised when one individual fills multiples roles in the security certification and accreditation

process to ensure that the individual retains an appropriate level of independence and remains free from conflicts of 

interest. 

22 When an agency has not designated a formal Chief Information Officer position, FISMA requires the associated

responsibilities to be handled by a comparable agency official. 

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Authorizing Official 

The authorizing official (or designated approving/accrediting authority as referred to by some

agencies) is a senior management official or executive with the authority to formally assume

responsibility for operating an information system at an acceptable level of risk to agency 

operations, agency assets, or individuals.

23 Through security accreditation, the authorizing official 

assumes responsibility and is accountable for the risks associated with operating an information 

system. The authorizing official should have the authority to oversee the budget and business 

operations of the information system within the agency and is often called upon to approve 

system security requirements, system security plans, and memorandums of agreement and/or 

memorandums of understanding. In addition to authorizing operation of an information system, 

the authorizing official can also: (i) issue an interim authorization to operate the information 

system under specific terms and conditions; or (ii) deny authorization to operate the information 

system (or if the system is already operational, halt operations) if unacceptable security risks 

exist. With the increasing complexities of agency missions and organizations, it is possible that a 

particular information system may involve multiple authorizing officials. If so, agreements 

should be established among the authorizing officials and documented in the system security

plan. In most cases, it will be advantageous to agree to a lead authorizing official to represent the 

interests of the other authorizing officials. The authorizing official has inherent U.S. government 

authority and, as such, must be a government employee. 

Authorizing Official Designated Representative

Due to the breadth of organizational responsibilities and significant demands on time, an 

authorizing official cannot always be expected to participate directly in the planning and technical 

meetings that occur during the security certification and accreditation process. The authorizing 

official’s designated representative is an individual acting on the authorizing official’s behalf in

coordinating and carrying out the necessary activities required during the security certification 

and accreditation of an information system. The authorizing official’s designated representative 

interacts with the senior agency information security officer, information system owner, 

information system security officer, certification agent, user representative(s), and other 

interested parties during the security certification and accreditation process. The designated 

representative can be empowered by the authorizing official to make certain decisions with regard 

to the planning and resourcing of the security certification and accreditation activities, the 

acceptance of the system security plan, and the determination of risk to agency operations, agency

assets, and individuals. The designated representative may also be called upon to prepare the 

final security accreditation package, obtain the authorizing official’s signature on the security

accreditation decision letter, and transmit the accreditation package to the appropriate agency

officials. The only activity that cannot be delegated by the authorizing official is the security

accreditation decision and the signing of the associated accreditation decision letter (i.e., the 

acceptability of risk to the agency). If a designated representative is not selected, the authorizing 

official is responsible for carrying out the activities described above. 

Senior Agency Information Security Officer 

The senior agency information security officer is the agency official responsible for: (i) carrying 

out the Chief Information Officer responsibilities under FISMA; (ii) possessing professional 

qualifications, including training and experience, required to administer the information security 

program functions; (iii) having information security duties as that official’s primary duty; and (iv) 

 

23 In some agencies, the senior official and the Chief Information Officer may be co-authorizing officials. In this

situation, the senior official approves the operation of the information system prior to the Chief Information Officer. 

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heading an office with the mission and resources to assist in ensuring agency compliance with 

FISMA. The senior agency information security officer (or supporting staff member) may also 

serve as the authorizing official's designated representative. The senior agency information 

security officer serves as the Chief Information Officer’s primary liaison to the agency’s

authorizing officials, information system owners, and information system security officers. 

Information System Owner 

The information system owner24 is an agency official responsible for the overall procurement, 

development, integration, modification, or operation and maintenance of an information system. 

The information system owner is responsible for the development and maintenance of the system

security plan and ensures the system is deployed and operated according to the agreed-upon 

security requirements. The information system owner is also responsible for deciding who has 

access to the information system (and with what types of privileges or access rights) and ensures 

that system users and support personnel receive the requisite security training (e.g., instruction in 

rules of behavior). The information system owner informs key agency officials of the need to 

conduct a security certification and accreditation of the information system, ensures that 

appropriate resources are available for the effort, and provides the necessary system-related 

documentation to the certification agent.25 The information system owner receives the security

assessment results from the certification agent. After taking appropriate steps to reduce or 

eliminate vulnerabilities, the information system owner assembles the security accreditation 

package and submits the package to the authorizing official or the authorizing official’s

designated representative for adjudication.26 

 Information Owner 

The information owner is an agency official with statutory or operational authority for specified 

information and responsibility for establishing the controls for its generation, collection, 

processing, dissemination, and disposal. The information owner is responsible for establishing 

the rules for appropriate use and protection of the subject information (e.g., rules of behavior) and 

retains that responsibility even when the information is shared with other organizations. The 

owner of the information stored within, processed by, or transmitted by an information system

may or may not be the same as the information system owner. Also, a single information system

may utilize information from multiple information owners. Information owners should provide

input to information system owners regarding the security requirements and security controls for 

the information systems where the information resides. 

Information System Security Officer

The information system security officer is the individual responsible to the authorizing official, 

information system owner, or the senior agency information security officer for ensuring the 

 

24 The role of information system owner can be interpreted in a variety of ways depending on the particular agency and 

the system development life cycle phase of the information system. Some agencies may refer to information system

owners as program managers or business/asset/mission owners. 

25 In some situations, the notification of the need to conduct a security certification and accreditation may come from 

the senior agency information security officer or authorizing official as they endeavor to ensure compliance with

federal or agency policy. The responsibility for ensuring appropriate resources are allocated to the security certification 

and accreditation effort depends on whether the agency uses a centralized or decentralized funding mechanism. 

26 Depending on how the agency has organized and structured its security certification and accreditation activities, the 

authorizing official may choose to designate an individual other than the information system owner to compile and

assemble the information for the accreditation package. In this situation, the designated individual must coordinate the 

compilation and assembly activities with the information system owner. 

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appropriate operational security posture is maintained for an information system or program. The 

information system security officer also serves as the principal advisor to the authorizing official, 

information system owner, or senior agency information security officer on all matters (technical 

and otherwise) involving the security of the information system. The information system security 

officer typically has the detailed knowledge and expertise required to manage the security aspects 

of the information system and, in many agencies, is assigned responsibility for the day-to-day

security operations of the system. This responsibility may also include, but is not limited to, 

physical security, personnel security, incident handling, and security training and awareness. The 

information system security officer may be called upon to assist in the development of the system

security policy and to ensure compliance with that policy on a routine basis. In close 

coordination with the information system owner, the information system security officer often 

plays an active role in developing and updating the system security plan as well as in managing 

and controlling changes to the system and assessing the security impact of those changes. 

Certification Agent 

The certification agent is an individual, group, or organization responsible for conducting a 

security certification, or comprehensive assessment of the management, operational, and 

technical security controls in an information system to determine the extent to which the controls 

are implemented correctly, operating as intended, and producing the desired outcome with respect 

to meeting the security requirements for the system. The certification agent also provides 

recommended corrective actions to reduce or eliminate vulnerabilities in the information system. 

Prior to initiating the security assessment activities that are a part of the certification process, the 

certification agent provides an independent assessment of the system security plan to ensure the 

plan provides a set of security controls for the information system that is adequate to meet all 

applicable security requirements. 

To preserve the impartial and unbiased nature of the security certification, the certification agent 

should be in a position that is independent from the persons directly responsible for the 

development of the information system and the day-to-day operation of the system. The 

certification agent should also be independent of those individuals responsible for correcting 

security deficiencies identified during the security certification. The independence of the 

certification agent is an important factor in assessing the credibility of the security assessment 

results and ensuring the authorizing official receives the most objective information possible in 

order to make an informed, risk-based, accreditation decision. The security category of the 

information system as defined in FIPS 199 should guide the degree of independence of the 

certification agent. When the potential impact on agency operations, agency assets, or individuals 

is low, a self-assessment activity may be reasonable and appropriate and not require an 

independent certification agent. When the potential agency-level impact is moderate or high, 

certification agent independence is needed and justified. 

User Representatives 

Users are found at all levels of an agency. Users are responsible for the identification of 

mission/operational requirements and for complying with the security requirements and security 

controls described in the system security plan. User representatives are individuals that represent 

the operational interests of the user community and serve as liaisons for that community

throughout the system development life cycle of the information system. The user representatives 

assist in the security certification and accreditation process, when needed, to ensure mission 

requirements are satisfied while meeting the security requirements and employing the security 

controls defined in the system security plan. 

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Delegation of Roles 

At the discretion of senior agency officials, certain security certification and accreditation roles 

may be delegated and if so, appropriately documented. Agency officials may appoint

appropriately qualified individuals, to include contractors, to perform the activities associated 

with any security certification and accreditation role with the exception of the Chief Information 

Officer and authorizing official. The Chief Information Officer and authorizing official have 

inherent United States Government authority, and those roles should be assigned to government 

personnel only. Individuals serving in delegated roles are able to operate with the authority of

agency officials within the limits defined for the specific certification and accreditation activities. 

Agency officials retain ultimate responsibility, however, for the results of actions performed by 

individuals serving in delegated roles.

2.3 ACCREDITATION BOUNDARIES

One of the most difficult and challenging problems for authorizing officials and senior agency 

information security officers is identifying appropriate security accreditation boundaries for 

agency information systems. Accreditation boundaries for agency information systems need to 

be established before the conduct of initial risk assessments and development of system security 

plans. Boundaries that are unnecessarily expansive (i.e., including too many hardware, software, 

and firmware components) make the security certification and accreditation process extremely

unwieldy and complex. Boundaries that are unnecessarily limited (i.e., including too few 

hardware, software, and firmware components) increase the number of security certifications and 

accreditations that must be conducted and thus drive up the total security costs for the agency. 

The guidelines in the following sections are provided to assist agencies in defining information 

system boundaries to strike a balance between the costs and benefits of security certification and 

accreditation. 

Establishing Information System Boundaries 

The process of uniquely assigning information resources27 to an information system defines the

security accreditation boundary for that system. Agencies have great flexibility in determining 

what constitutes an information system (i.e., major application or general support system) and the 

resulting security accreditation boundary that is associated with that system. If a set of 

information resources is identified as an information system, the resources should generally be 

under the same direct management control.28 Direct management control does not necessarily 

imply that there is no intervening management. It is quite possible for multiple information 

systems to be validly considered subsystems29 of a single, larger system provided all of these 

subsystems fall under the same higher management authority. This situation may arise in many

agencies when other than major applications (i.e., minor applications) are coalesced for purposes 

of security certification and accreditation into a general support system. In addition to the 

 

27 Information resources consist of information and related resources, such as personnel, equipment, funds, and

information technology.

28 Direct management control typically involves budgetary, programmatic, or operational authority and associated 

responsibility. For new information systems, management control can be interpreted as having budgetary/programmatic 

authority and responsibility for the development and deployment of the information systems. For information systems 

currently in the federal inventory, management control can be interpreted as having budgetary/operational authority for 

the day-to-day operations and maintenance of the information systems.

29 A subsystem is a major subdivision or component of an information system consisting of information, information 

technology, and personnel that performs one or more specific functions. 

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consideration of direct management control, it may also be helpful for agencies to consider if the 

information resources being identified as an information system: 

• Have the same function or mission objective and essentially the same operating 

characteristics and security needs; and 

• Reside in the same general operating environment (or in the case of a distributed information 

system, reside in various locations with similar operating environments). 

While the above considerations may be useful to agencies in determining information system

boundaries for purposes of security accreditation, they should not be viewed as limiting the 

agency’s flexibility in establishing common sense boundaries that promote effective information 

security within the available resources of the agency. Authorizing officials and senior agency

information security officers should consult with prospective information system owners when 

establishing information system and security accreditation boundaries. The process of 

establishing boundaries for agency information systems and the associated security certification 

and accreditation implications, is an agency-level activity that should include careful negotiation 

among all key participants—taking into account the mission/business requirements of the agency, 

the technical considerations with respect to information security, and the programmatic costs to 

the agency. 

Supplementing the above considerations, FIPS 199, Standards for Security Categorization of

Federal Information and Information Systems, defines security categories for information 

systems based on potential impact on organizations or individuals should there be a breach of 

security—that is, a loss of confidentiality, integrity (including authenticity and non-repudiation), 

or availability.30 FIPS 199 security categories can play an important part in defining accreditation 

boundaries by partitioning the agency’s information systems according to the criticality or

sensitivity of the systems and the importance of those systems in accomplishing the agency’s 

mission. The partitioning process facilitates the cost-effective application of security controls to 

achieve adequate security commensurate with the mission/business functions being supported by

the respective information systems.

Boundaries for Large and Complex Information Systems 

The application of security controls within large and complex information systems, even when

using FIPS 199 to categorize those systems, may be cost-prohibitive and technically infeasible for 

the agency. Accordingly, any attempt to assess the security controls in such systems may also be 

cost-prohibitive and unrealistic. To make this problem more manageable, authorizing officials 

should examine the nature of the information systems being considered for security certification 

and accreditation and the feasibility of decomposing the systems into more manageable 

components. The decomposition of large and complex systems into multiple components, or 

subsystems, facilitates the application of the security certification and accreditation process in a 

more cost-effective manner. 

 

30 Based on the definitions provided in OMB Circular A-130, Appendix III, agencies can associate the different types

of information systems and applications with the security categories and impact levels defined in FIPS 199. For 

example, a major application could be expected to have a potential impact level of moderate or high in its security

categorization. A minor application could be expected to have a potential impact level of low or moderate in its security

categorization. A general support system could be expected to have a potential impact level of low, moderate, or high 

in its security categorization depending on the criticality or sensitivity of the system, potential impact of loss, and

whether the system is supporting (i.e., hosting) any major applications. Minor applications are typically included (or

bundled) within a general support system. 

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For large and complex information systems, the authorizing official and senior agency

information security officer may define subsystem components with established subsystem

boundaries. The decomposition into subsystem components should be reflected in the system 

security plan for that large and complex information system. Each subsystem component is fully 

described in the system security plan, an appropriate security category assigned in accordance 

with FIPS 199, and an appropriate set of security controls identified. The extent to which the 

security controls are implemented correctly, operating as intended, and producing the desired 

outcome with respect to meeting the security requirements for the information system, can be 

determined by combining security assessments at the subsystem level and adding system-level

considerations. This facilitates a more cost-effective certification and accreditation process by 

enabling scaling of the effort at the subsystem level in accordance with that subsystem’s security 

category and allowing for reuse of certification results at the system level. 

To illustrate a simple example of system decomposition and the resulting subsystems, consider a 

general support system that contains a system guard that monitors the flow of information 

between two local area networks. The general support system, in this case, can be partitioned 

into three subsystem components: (i) local area network Alpha; (ii) local area network Bravo; and 

(iii) the system guard separating the two networks.31 When all subsystems within the information 

system have completed the security certification process, an additional certification is performed 

on the system-level security controls not covered by the individual subsystem certifications, and 

the results are bundled together into the accreditation package and presented as evidence to the 

authorizing official. Figure 2.2 illustrates the concept of information system decomposition and 

the security certification and accreditation process for a large and complex system. 

LOCAL AREA

NETWORK 

ALPHA

Subsystem Boundary

SYSTEM 

GUARD

Subsystem Boundary

LOCAL AREA

NETWORK 

BRAVO

Subsystem Boundary

General Support System Boundary

• System security plan reflects information system decomposition with adequate security

controls assigned to each subsystem component 

• Security assessment methods and procedures tailored for the security controls in each 

subsystem component and for the combined system level 

• Security certification performed on each subsystem component and on system-level 

controls not covered by subsystem certifications 

• Security accreditation performed on the information system as a whole 

AGENCY GENERAL SUPPORT SYSTEM

FIGURE 2.2 DECOMPOSITION OF LARGE AND COMPLEX INFORMATION SYSTEMS

 

31 Each subsystem component within the information system can be assigned a security categorization in accordance 

with FIPS 199. The overall security categorization of the information system can be determined by taking the high

water mark of the security categorizations of the individual subsystem components.

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2.4 COMMON SECURITY CONTROLS

An agency-wide view of the security program facilitates the identification of common security 

controls that can be applied to one or more agency information systems. Common security controls 

can apply to: (i) all agency information systems; (ii) a group of information systems at a specific site 

(sometimes associated with the terms site certification/accreditation); or (iii) common information 

systems, subsystems, or applications (i.e., common hardware, software, and/or firmware) deployed at

multiple operational sites (sometimes associated with the terms type certification/accreditation). 

Common security controls, typically identified during a collaborative agency-wide process with the

involvement of the Chief Information Officer, senior agency information security officer, authorizing 

officials, information system owners, and information system security officers (and by developmental 

program managers in the case of common security controls for common hardware, software, and/or

firmware) have the following properties: 

• The development, implementation, and assessment of common security controls can be assigned

to responsible agency officials or organizational elements (other than the information system

owners whose systems will implement or use those common security controls); and

• The results from the assessment of the common security controls can be used to support the 

security certification and accreditation processes of agency information systems where those 

controls have been applied. 

Many of the management and operational controls (e.g., contingency planning controls, incident 

response controls, security training and awareness controls, personnel security controls, and 

physical security controls) needed to protect an information system may be excellent candidates 

for common security control status. The objective is to reduce security costs by centrally

managing the development, implementation, and assessment of the common security controls 

designated by the agency—and subsequently, sharing assessment results with the owners of 

information systems where those common security controls are applied. Security controls not 

designated as common controls are considered system-specific controls and are the responsibility 

of the information system owner. System security plans should clearly identify which security 

controls have been designated as common security controls and which controls have been 

designated as system-specific controls. 

2.5 ACCREDITATION DECISIONS

Security accreditation decisions resulting from security certification and accreditation processes 

should be conveyed to information system owners. To ensure the agency’s business and 

operational needs are fully considered, the authorizing official should meet with the information 

system owner prior to issuing the security accreditation decision to discuss the security 

certification findings and the terms and conditions of the authorization. There are three types of 

accreditation decisions that can be rendered by authorizing officials: 

• Authorization to operate; 

• Interim authorization to operate; and 

• Denial of authorization to operate. 

Authorization to Operate

If, after assessing the results of the security certification, the authorizing official deems that the 

risk to agency operations, agency assets, or individuals is acceptable, an authorization to operate

is issued for the information system. The information system is authorized without any

significant restrictions or limitations on its operation. Although not affecting the security

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accreditation decision, authorizing officials should take specific actions to reduce or eliminate 

identified vulnerabilities, where it is cost-effective to do so. The information system owner 

should establish a disciplined and structured process to monitor the effectiveness of the security 

controls in the information system and the progress of any corrective actions on a continuous 

basis. Security reaccreditation occurs at the discretion of the authorizing official when significant 

changes have taken place in the information system or when a specified time period has elapsed 

in accordance with federal or agency policy.

Interim Authorization to Operate 

If, after assessing the results of the security certification, the authorizing official deems that the 

risk to agency operations, agency assets, or individuals is unacceptable, but there is an 

overarching mission necessity to place the information system into operation or continue its 

operation, an interim authorization to operate may be issued. An interim authorization to operate 

is rendered when the identified security vulnerabilities in the information system resulting from

deficiencies in the planned or implemented security controls are significant but can be addressed 

in a timely manner.32 An interim authorization provides a limited authorization to operate the 

information system under specific terms and conditions and acknowledges greater risk to the 

agency for a specified period of time. The terms and conditions, established by the authorizing 

official, convey limitations on information system operations. 

In accordance with OMB policy, an information system is not accredited during the period of 

limited authorization to operate. The duration established for an interim authorization to operate 

should be commensurate with the risk to agency operations, agency assets, or individuals 

associated with the operation of the information system. When the security-related deficiencies

have been adequately addressed, the interim authorization should be lifted and the information 

system authorized to operate. Security reaccreditation occurs at the discretion of the authorizing 

official when significant changes have taken place in the information system or when a specified 

time period has elapsed in accordance with federal or agency policy. The time period for 

reaccreditation is calculated from the date the information system receives its authorization to 

operate. 

The plan of action and milestones submitted by the information system owner is used by the 

authorizing official to monitor the progress in correcting deficiencies noted during the security 

certification. In addition to executing the plan of action and milestones, information system

owners should also establish a disciplined and structured process to monitor the effectiveness of 

the security controls in the information system during the period of limited authorization to 

operate. Monitoring activities should focus on the specific vulnerabilities in the information 

system identified during the security certification. Significant changes in the security state of the 

information system that occur during the period of limited authorization to operate should be 

reported immediately to the authorizing official. 

 

32 Since information system owners are involved in the planning process that establishes timeframes for conducting

security certification and accreditation activities, they are in a good position to address security-related deficiencies in a 

timely manner before the certification and accreditation process begins. Mitigating security vulnerabilities in the

information system as soon as possible before the vulnerabilities rise to higher levels of significance or seriousness 

ensures that the interim authorization to operate remains a viable option. Information systems, especially missioncritical or high-impact systems as described in FIPS 199, should not be operating with significant security

vulnerabilities requiring extended remediation time. 

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Denial of Authorization to Operate 

If, after assessing the results of the security certification, the authorizing official deems that the 

risk to agency operations, agency assets, or individuals is unacceptable, the authorization to 

operate the information system is denied. The information system is not accredited and should 

not be placed into operation. If the information system is currently in operation, all activity

should be halted. Failure to receive authorization to operate, or an interim authorization to 

operate, usually indicates that there are major deficiencies in the security controls in the 

information system. The authorizing official or designated representative should work with the 

information system owner to revise the plan of action and milestones to ensure that proactive 

measures are taken to correct the security deficiencies in the information system. 

Previous Authorizations

In the event that a new authorizing official is assigned responsibility for the information system, 

the newly assigned authorizing official should review the current security accreditation package 

(i.e., accreditation decision, decision rationale, and terms and conditions) and the current status 

reports from the continuous monitoring process to determine if a reaccreditation action is 

warranted. If the new authorizing official is willing to accept the currently documented risk, then 

reaccreditation occurs only when there is a significant change to the information system or when

a specified time period has elapsed in accordance with federal or agency policy.

2.6 SUPPORTING DOCUMENTATION

The security accreditation package documents the results of the security certification and 

provides the authorizing official with the essential information needed to make a credible, riskbased decision on whether to authorize operation of the information system. Unless specifically

designated otherwise by the Chief Information Officer or authorizing official, the information 

system owner is responsible for the assembly, compilation, and submission of the security

accreditation package. The information system owner receives inputs from the information 

system security officer, certification agent, and senior agency information security officer during 

the preparation of the security accreditation package. The security accreditation package contains 

the following documents: 

• Approved system security plan;33

• Security assessment report; and 

• Plan of action and milestones. 

The system security plan, prepared by the information system owner and previously approved by

the authorizing official and/or senior agency information security officer, provides an overview of 

the security requirements for the information system and describes the security controls in place 

or planned for meeting those requirements. The plan can also contain as supporting appendices 

or as references, other key security-related documents for the information system such as the risk 

assessment, privacy impact assessment, contingency plan, incident response plan, configuration 

management plan, security configuration checklists, and any system interconnection agreements. 

The security assessment report, prepared by the certification agent, provides the results of 

assessing the security controls in the information system to determine the extent to which the 

controls are implemented correctly, operating as intended, and producing the desired outcome 

 

33 The initial risk assessment, included as an appendix to the system security plan or referenced in the plan, is updated 

by the information system owner prior to the final assembly of the security accreditation package.

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with respect to meeting the system security requirements. The security assessment report can 

also contain a list of recommended corrective actions. 

The plan of action and milestones, which is prepared by the information system owner, describes 

the measures that have been implemented or planned: (i) to correct any deficiencies noted during 

the assessment of the security controls; and (ii) to reduce or eliminate known vulnerabilities in the 

information system. The information system owner submits the final security accreditation 

package to the authorizing official or designated representative.34 Figure 2.3 illustrates the key

sections of the security accreditation package.

AUTHORIZING 

OFFICIAL

OR

DESIGNATED

REPRESENTATIVE PLAN OF ACTION

AND MILESTONES

SECURITY ASSESSMENT 

REPORT

− Overview of the security requirements, 

the agreed-upon security contro

supporting security-related docum

such as risk assessment.

Security control a

ls, and

ents

− ssessment results 

.

− Measures implemented or planned to

and recommended corrective actions

correct deficiencies and to reduce or 

eliminate known vulnerabilities. 

SYSTEM SECURITY 

PLAN

FIGURE 2.3 CONTENTS OF THE SECURITY ACCREDITATION PACKAGE

The security accreditation decision letter transmits the security accreditation decision from the 

authorizing official to the information system owner. The authorizing official’s designated 

representative prepares the final security accreditation decision letter for the authorizing official 

with authorization recommendations, as appropriate. The security accreditation decision letter 

contains the following information: 

• Security accreditation decision; 

• Supporting rationale for the decision; and 

• Terms and conditions for the authorization. 

The security accreditation decision letter indicates to the information system owner whether the 

system is: (i) authorized to operate; (ii) authorized to operate on an interim basis under strict 

terms and conditions; or (iii) not authorized to operate. The supporting rationale provides the 

information system owner with the justification for the authorizing official’s decision. The terms 

and conditions for the authorization provide a description of any limitations or restrictions placed 

on the operation of the information system that must be adhered to by the information system

owner. The security accreditation decision letter is attached to the original accreditation package 

and returned to the information system owner. 

Upon receipt of the security accreditation decision letter and accreditation package, the 

information system owner accepts the terms and conditions of the authorization. The information 

 

34 Security accreditation packages can be submitted in either paper or electronic format. Appropriate measures should 

be employed to protect the information contained in accreditation packages (electronic or paper format) in accordance

with agency policy. 

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system owner keeps the original security accreditation decision letter and accreditation package 

on file. The authorizing official and senior agency information security officer also retain copies 

of the security accreditation decision letter and accreditation package. The contents of security 

certification and accreditation-related documentation (especially information dealing with 

information system vulnerabilities) should be: (i) marked and protected appropriately in 

accordance with agency policy; and (ii) retained in accordance with the agency’s record retention 

policy.

2.7 CONTINUOUS MONITORING

A critical aspect of the security certification and accreditation process is the post-accreditation 

period involving the continuous monitoring of security controls in the information system over 

time. An effective continuous monitoring program requires: 

• Configuration management and configuration control processes; 

• Security impact analyses on changes to the information system; and 

• Assessment of selected security controls in the information system and security status 

reporting to appropriate agency officials.35

With regard to configuration management and control, it is important to document the proposed 

or actual changes to the information system and to subsequently determine the impact of those 

proposed or actual changes on the security of the system. Information systems will typically be 

in a constant state of migration with upgrades to hardware, software, or firmware and possible 

modifications to the surrounding environment where the system resides. Documenting 

information system changes and assessing the potential impact those changes may have on the 

security of the system is an essential aspect of continuous monitoring and maintaining the 

security accreditation. 

Realizing that it is not feasible or cost-effective to monitor all of the security controls in an 

information system on a continuous basis, the information system owner should select an 

appropriate subset of those controls for periodic assessment.36 The criteria established by the 

information system owner for selecting which security controls will be monitored and for 

determining the frequency of such monitoring activity should reflect the agency’s priorities and 

importance of the information system to agency operations, agency assets, or individuals.37 The 

authorizing official and the senior agency information security officer should approve the set of 

security controls that are to be monitored on a continuous basis as well as the monitoring 

frequency.

The results of continuous monitoring should be documented and reported to the authorizing 

official and senior agency information security officer on a regular basis. The continuous 

monitoring results should also be considered with respect to any necessary updates to the system

security plan and to the plan of action and milestones, since the authorizing official, senior 

agency information security officer, information system owner, and certification agent will be 

using these plans to guide future security certification and accreditation activities. The plan of 

 

35 At the discretion of the agency, the security status reports on agency information systems can be used to help satisfy 

the FISMA reporting requirement for documenting remedial actions for any security-related deficiencies. 

36 NIST Special Publication 800-53A provides guidance for assessing the security controls in an information system. 

37 FIPS 199 security categorizations should be used to determine agency priorities and importance of information

systems.

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action and milestones should: (i) report progress made on the current outstanding items listed in 

the plan; (ii) address vulnerabilities in the information system discovered during the security

impact analysis or security control monitoring; and (iii) describe how the information system

owner intends to address those vulnerabilities (i.e., reduce, eliminate, or accept the identified 

vulnerabilities). The monitoring of security controls in the information system continues 

throughout the system development life cycle. Reaccreditation occurs when there are significant 

changes to the information system affecting the security of the system or when a specified time 

period has elapsed in accordance with federal or agency policy.

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CHAPTER THREE

THE PROCESS

PHASES AND TASKS ASSOCIATED WITH SECURITY CERTIFICATION AND ACCREDITATION 

he security certification and accreditation process consists of four distinct phases: (i) an 

Initiation Phase; (ii) a Security Certification Phase; (iii) a Security Accreditation Phase; 

and (iv) a Continuous Monitoring Phase. Each phase consists of a set of well-defined 

tasks and subtasks that are to be carried out, as indicated, by responsible individuals (e.g., the 

Chief Information Officer, authorizing official, authorizing official’s designated representative,

senior agency information security officer, information system owner, information owner, 

information system security officer, certification agent, and user representatives). The security 

certification and accreditation activities can be applied to an information system at appropriate 

phases in the system development life cycle. Additionally, the activities can be tailored to apply a 

level of effort and rigor that is most suitable for the information system undergoing security

certification and accreditation. Figure 3.1 provides a high-level view of the security certification 

and accreditation process including the tasks associated with each phase in the process. A 

summary table of all security certification and accreditation tasks and subtasks and the 

individuals responsible for accomplishing those tasks and subtasks is provided in Appendix D.

T

• Configuration Management and Control 

• Security Control Monitoring 

• Status Reporting and Documentation 

• Security Accreditation Decision 

• Security Accreditation Documentation

• Preparation 

• Notification and Resource Identification 

• System Security Plan Analysis, Update, and Acceptance

INITIATION

PHASE

SECURITY

CERTIFICATION PHASE

SECURITY

ACCREDITATION PHASE

• Security Control Assessment

• Security Certification Documentation 

CONTINUOUS

MONITORING PHASE

FIGURE 3.1 SECURITY CERTIFICATION AND ACCREDITATION PROCESS

Scalability of the Security Certification and Accreditation Process 

There is a general expectation that the level of effort for security certification and accreditation 

(expressed in terms of degree of rigor and formality) should be scalable to the FIPS 199 security 

category of the information system. The concept is straightforward—the agency information 

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systems with greater sensitivity and/or criticality have greater potential for adversely affecting 

agency operations, agency assets, or individuals and therefore demand: 

• Greater protection through the application of stronger security controls; and 

• Greater scrutiny with regard to the assessment of those security controls to determine the 

extent to which the controls are implemented correctly, operating as intended, and producing 

the desired outcome with respect to meeting the security requirements for the system. 

The FIPS 199 security category of an information system influences the initial selection of 

security controls from NIST Special Publication 800-53 and the initial selection of assessment 

methods and procedures from NIST Special Publication 800-53A. The level of effort applied to

the security certification and accreditation tasks and subtasks should be commensurate with the 

strength of the security controls selected and the rigor and formality of the assessment methods 

and procedures selected. The tasks outlined in this chapter apply to all FIPS 199 security

categories. However, the scalability of the security certification and accreditation process can be 

applied to low-impact information systems. As stated in FIPS 199: 

“For a low-impact information system, the loss of confidentiality, integrity, or availability could be

expected to have a limited adverse effect on agency operations, agency assets, or individuals. A limited 

adverse effect means that, for example, the loss of confidentiality, integrity, or availability might: (i) cause 

a degradation in mission capability to an extent and duration that the organization is able to perform its 

primary functions, but the effectiveness of the functions is noticeably reduced; (ii) result in minor damage 

to organizational assets; (iii) result in minor financial loss; or (iv) result in minor harm to individuals.” 

Since the agency-level risk in operating a low-impact information system is minimal, by

definition, the level of effort applied to the security certification and accreditation of that system

should be commensurate with that level of risk. While all of the certification and accreditation 

tasks apply to low-impact information systems, supplemental guidance is provided in the subtasks 

to address the appropriate level of effort (i.e., degree of rigor and formality) for the certification 

and accreditation process.38 The scalability of the certification and accreditation process for lowimpact systems results in the elimination of the independent certification agent, the incorporation 

of self-assessment activities, and a reduction in the associated level of supporting documentation. 

3.1 INITIATION PHASE

The Initiation Phase consists of three tasks: (i) preparation; (ii) notification and resource 

identification; and (iii) system security plan analysis, update, and acceptance. The purpose of this 

phase is to ensure that the authorizing official and senior agency information security officer are 

in agreement with the contents of the system security plan, including the system’s documented

security requirements, before the certification agent begins the assessment of the security controls 

in the information system. The early involvement of the authorizing official and senior agency 

information security officer, with key participants such as the information system owner, 

information owner, information system security officer, certification agent, and user 

representatives, is paramount to the success of the security certification and accreditation effort. 

A significant portion of the information needed for the Initiation Phase should have been 

previously generated by the information system owner during: (i) the initial risk assessment; (ii) 

 

38 Supplemental guidance is not provided for all subtasks in the certification and accreditation process. Guidance for 

scaling the level of effort applied to the development of system security plans, the selection of security controls, and the

conduct of risk assessments is beyond the scope of this publication.

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the development of the system security plan; and (iii) the conduct of previous assessments (e.g., 

security testing and evaluation, independent verification and validation, independent audits). For 

new information systems or systems undergoing major upgrades, this information is typically

produced during the initiation phase of the system development life cycle when system

requirements are established. For legacy systems currently in the operations and maintenance 

phase of the system development life cycle, this information is obtained from the most recent 

system security plans and risk assessments. In most cases, risk assessments and system security 

plans have been previously reviewed and approved by agency officials. Thus, the subtasks in 

Task 1 (preparation task) should not require any additional work on the part of the information 

system owner above and beyond what has already been accomplished as part of the system

development life cycle. Rather, the Initiation Phase of the security certification and accreditation 

process serves as a checkpoint to confirm that the system security plan and risk assessment have 

been completed. If an information system owner has not completed a risk assessment and a 

system security plan, those activities should be completed prior to proceeding with the security 

certification and accreditation process. 

TASK 1: PREPARATION

The objective of the preparation task is to prepare for security certification and accreditation by 

reviewing the system security plan and confirming that the contents of the plan are consistent 

with an initial assessment of risk. 

INFORMATION SYSTEM DESCRIPTION

SUBTASK 1.1: Confirm that the information system has been fully described and documented in the 

system security plan or an equivalent document. 

RESPONSIBILITY: Information System Owner.39

GUIDANCE: A typical system description includes: (i) the name of the information 

system; (ii) a unique identifier for the information system; (iii) the status of the 

information system with respect to the system development life cycle; (iv) the name

and location of the organization responsible for the information system; (v) contact 

information for the information system owner or other individuals knowledgeable 

about the information system; (vi) contact information for the individual(s) 

responsible for the security of the information system; (vii) the purpose, functions, 

and capabilities of the information system; (viii) the types of information processed,

stored, and transmitted by the information system; (ix) the boundary of the 

information system for operational authorization (or security accreditation); (x) the 

functional requirements of the information system; (xi) the applicable laws, 

directives, policies, regulations, or standards affecting the security of the information 

and the information system; (xii) the individuals who use and support the information 

system (including their organizational affiliations, access rights, privileges, and

citizenship, if applicable); (xiii) the architecture of the information system; (xiv) 

hardware and firmware devices (including wireless); (xv) system and applications 

software (including mobile code); (xvi) hardware, software, and system interfaces 

(internal and external); (xvii) information flows (i.e., inputs and outputs); (xviii) the

 

39 Agencies have significant flexibility in assigning security certification and accreditation responsibilities. Some

agencies may employ a shared model of responsibility with the senior agency information security officer called upon 

to assist the information system owner in carrying out security certification and accreditation tasks/subtasks. The 

delineation and assignment of specific security certification and accreditation responsibilities is handled by agencies on 

a case-by-case basis in accordance with their organizational structures. 

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network topology; (xix) network connection rules for communicating with external

information systems; (xx) interconnected information systems and unique identifiers

for those systems; (xxi) encryption techniques used for information processing, 

transmission, and storage; (xxii) public key infrastructures, certificate authorities, and 

certificate practice statements; (xxiii) the physical environment in which the

information system operates; and (xxiv) web protocols and distributed, collaborative 

computing environments (processes, and applications). The level of detail provided 

in the system security plan depends on the availability of information to the 

organization preparing the plan and is also commensurate with the FIPS 199 security

category of the information system (i.e., the level of detail in the system security plan

increases as the potential impact on agency operations, agency assets, or individuals

increases). Descriptive information about the information system is typically

documented in the system identification section of the system security plan or in

some cases, included in attachments to the plan. System identification information 

can also be provided by reference. 

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: NIST Special Publications 800-18, 800-30, or equivalents.

SECURITY CATEGORIZATION

SUBTASK 1.2: Confirm that the security category of the information system has been determined 

and documented in the system security plan or an equivalent document. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: Consult NIST Special Publication 800-59 to confirm that the information

system is other than a national security system. For other than national security

systems, FIPS 199 establishes three potential impact levels (low, moderate, and high) 

for each of the stated security objectives (confidentiality, integrity, and availability) 

relevant to securing federal information systems. These impact levels focus on the 

potential impact and magnitude of harm that the loss of confidentiality, integrity, or 

availability would have on agency operations, agency assets, or individuals. It is 

recognized that an information system may contain more than one type of 

information (e.g., privacy information, medical information, proprietary information,

financial information, contractor sensitive information, system security information),

each of which is subject to security categorization. The security category of an 

information system that processes, stores, or transmits multiple types of information 

should be at least the highest impact level that has been determined for each type of 

information for each security objective of confidentiality, integrity, and availability.

The FIPS 199 security category should be considered during the risk assessment to 

help guide the information system owner’s selection of security controls for the

information system. Security categorization information is typically documented in

the system identification section of the system security plan or included as an 

attachment to the plan.

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: FIPS 199; NIST Special Publications 800-18, 800-30, 800-59, 800-60, 

or equivalents.

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THREAT IDENTIFICATION

SUBTASK 1.3: Confirm that potential threats that could exploit information system flaws or 

weaknesses have been identified and documented in the system security plan, risk 

assessment, or an equivalent document. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: It is important to consider all potential threats that could cause harm to an

information system, ultimately affecting the confidentiality, integrity, or availability

of the system. Threats can be natural (floods, earthquakes, tornadoes, landslides, 

avalanches, electrical storms), human (events that are either enabled by or caused by 

human beings), or environmental (long-term power failures, pollution, chemicals, 

liquid leakage). It should be noted that all possible threats that might be encountered 

in the environment need not be listed—only those that are relevant to the security of 

the information system. Threat information (including capabilities, intentions, and

resources of potential adversaries) for a specific information system is generally

nonspecific or incomplete at best. Recognizing the highly networked nature of the 

current federal computing environment, there exists an acknowledged set of baseline

threats to all information systems. In other words, in today's interconnected and

interdependent information systems environment, which encompasses many common 

platforms and technologies, there is a high likelihood of a variety of threats (both 

intentional and unintentional) acting to compromise the security of agency

information systems. In addition to this generalized assumption about threats,

specific threat information, if available, should be used during the risk assessment to

help guide the selection of security controls for the information system. Threat 

information should be coordinated with the senior agency information security

officer and authorizing official to facilitate reuse and sharing with other information

system owners, agency-wide. The level of effort (i.e., degree of rigor and formality) 

applied to the threat identification process should be commensurate with the FIPS 

199 security category of the information system (i.e., the level of effort increases as

the potential impact on agency operations, agency assets, or individuals increases). 

Threat identification information is typically documented in the risk assessment, 

which should be included in the system security plan either by reference or as an

attachment.

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: NIST Special Publications 800-18, 800-30, or equivalents.

VULNERABILITY IDENTIFICATION

SUBTASK 1.4: Confirm that flaws or weaknesses in the information system that could be exploited 

by potential threat sources have been identified and documented in the system

security plan, risk assessment, or an equivalent document. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: Flaws or weaknesses in an information system that could be exploited by

potential threats determine the potential vulnerabilities in that system. Vulnerability

identification can be conducted at any phase in the system development life cycle. If 

the system is under development, the search for vulnerabilities focuses on the 

organization’s security policies, planned security procedures, system requirement 

definitions, and developer security product analyses. If the system is being

implemented, the identification of vulnerabilities is expanded to include more 

specific information, such as the planned security features described in the security 

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design documentation and the results of the developmental security test and 

evaluation. If the system is operational, the process of identifying vulnerabilities 

includes an analysis of the system security controls employed to protect the system. 

The identification of vulnerabilities can be accomplished in a variety of ways using 

questionnaires, on-site interviews, document reviews, and automated scanning tools.

Vulnerability sources include, for example: (i) previous risk assessment 

documentation; (ii) audit reports; (iii) system anomaly reports; (iv) security reviews;

(v) self assessments; (vi) results of vulnerability scans and penetration tests; (vii) 

security test and evaluation reports; (viii) previous assessment reports from security

certifications; (ix) vulnerability lists; (x) security advisories; (xi) vendor advisories; 

(xii) commercial computer incident/emergency response teams and post lists; (xiii) 

information security vulnerability alerts and bulletins; and (xiv) hardware, software, 

or firmware security analyses. Vulnerability information associated with systemspecific and common security controls should be coordinated with the senior agency

information security officer and authorizing officials to facilitate reuse and sharing 

with other information system owners agency-wide. The level of effort (i.e., degree

of rigor and formality) applied to the vulnerability identification process should be

commensurate with the FIPS 199 security category of the information system (i.e., 

the level of effort increases as the potential impact on agency operations, agency 

assets, or individuals increases). Vulnerability identification information is typically

documented in the risk assessment report, which should be included in the system

security plan either by reference or as an attachment. 

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: NIST Special Publications 800-18, 800-30, or equivalents. 

SECURITY CONTROL IDENTIFICATION

SUBTASK 1.5: Confirm that the security controls (either planned or implemented) for the 

information system have been identified and documented in the system security plan

or an equivalent document. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: Security controls for information systems are listed in NIST Special

Publication 800-53, Recommended Security Controls for Federal Information 

Systems. These predefined sets of security controls (targeted to the security

categories defined in FIPS 199) provide a baseline or starting point for agencies in

addressing the necessary safeguards and countermeasures required for their 

information systems. Common security controls should be identified during a 

collaborative agency-wide process with the involvement of the senior agency 

information security officer, authorizing officials, information system owners, and 

information system security officers (or by the developmental program manager in

the case of common security controls for common hardware software and/or 

firmware). Agencies should perform additional analyses to determine if adjustments 

to the baseline set of security controls are needed. These adjustments to the baseline 

set of security controls should be based on specific threat and vulnerability

information generated during the risk assessment for the information system and the 

agency's determination of acceptable risk. Adjustments to the baseline set of security

controls should be reasonable, appropriate, and fully documented in the system

security plan with supporting rationale. Upon completion of the security control

identification process, the agreed-upon set of controls should adequately protect the

confidentiality, integrity, and availability of the system and its information. The level 

of effort (i.e., degree of rigor and formality) applied to the security control selection

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process should be commensurate with the FIPS 199 security category of the 

information system (i.e., the level of effort increases as the potential impact on

agency operations, agency assets, or individuals increases). Security controls are 

typically documented in the system security plan. 

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: NIST Special Publications 800-18, 800-30, 800-53, or equivalents. 

INITIAL RISK DETERMINATION

SUBTASK 1.6: Confirm that the risk to agency operations, agency assets, or individuals has been

determined and documented in the system security plan, risk assessment, or an 

equivalent document. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: FISMA and OMB Circular A-130, Appendix III, require risk assessments 

as part of a risk-based approach to determining adequate, cost-effective security for 

an information system. The methods used to assess risk should include consideration 

of the major factors in risk management including: (i) threats to and vulnerabilities in 

the information system; (ii) potential impact and magnitude of harm to agency

operations, agency assets, or individuals that could result from the unauthorized 

access, use, disclosure, disruption, modification, or destruction of information and 

the information system; and (iii) the effectiveness of current or proposed security

controls. It is impractical, in most cases, to plan for or implement security controls 

that address all potential vulnerabilities. Vulnerabilities resulting from the absence of

security controls or the ineffectiveness of controls (i.e., controls not implemented 

correctly, not operating as intended, or not producing the desired outcome with

respect to meeting system security requirements) provide the basis for determining

the agency-level risk posed by the operation of the information system. The level of 

effort (i.e., degree of rigor and formality) applied to the risk assessment should be

commensurate with the FIPS 199 security category of the information system (i.e., 

the level of effort increases as the potential impact on agency operations, agency 

assets, or individuals increases). Assessing agency-level risk should be an ongoing

activity to ensure that as new threats and vulnerabilities are identified, adequate

security controls are implemented. Agency-level risk is typically documented in the 

risk assessment, which should be included in the system security plan either by

reference or as an attachment. 

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: FISMA; OMB Circular A-130, Appendix III; NIST Special 

Publication 800-30, or equivalent. 

TASK 2: NOTIFICATION AND RESOURCE IDENTIFICATION

The objective of the notification and resource identification task is to: (i) provide notification to

all concerned agency officials as to the impending security certification and accreditation of the 

information system; (ii) determine the resources needed to carry out the effort; and (iii) prepare a 

plan of execution for the certification and accreditation activities indicating the proposed schedule 

and key milestones. 

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NOTIFICATION

SUBTASK 2.1: Inform the senior agency information security officer, authorizing official,

certification agent, user representatives, and other interested agency officials that the 

information system requires security certification and accreditation support. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: The initial notification of key agency officials is an important activity to

establish the security certification and accreditation process as an integral part of the 

system development life cycle. The notification also serves as an early warning to

help prepare potential participants for the upcoming tasks that will be necessary to

plan, organize, and conduct the security certification and accreditation. In some

instances, the authorizing official or senior agency information security officer 

provides the initial notification to the information system owner and other key

agency officials. This typically occurs when a specified time period has elapsed and 

the information system must undergo reaccreditation in accordance with federal or 

agency policy.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, a simplified

notification procedure is recommended. The information system owner notifies the 

authorizing official and senior agency information security officer that a self-assessment

of the information system security controls is planned and provides an estimated

completion date.

REFERENCE: OMB Circular A-130, Appendix III. 

PLANNING AND RESOURCES

SUBTASK 2.2: Determine the level of effort and resources required for the security certification and 

accreditation of the information system (including organizations involved) and 

prepare a plan of execution.

RESPONSIBILITY: Authorizing Official; Senior Agency Information Security Officer; 

Information System Owner; Certification Agent.

GUIDANCE: The level of effort required for security certification depends on: (i) the 

size and complexity of the information system; (ii) the FIPS 199 security category of

the system; (iii) the security controls employed to protect the system; and (iv) the 

specific methods and procedures used to assess the security controls in the system to 

determine the extent to which the controls are implemented correctly, operating as 

intended, and producing the desired outcome with respect to meeting the security

requirements for the system. Identifying appropriate resources (e.g., supporting 

organizations, funding, and individuals with critical skills) needed for the security

certification effort is an essential aspect of the initial preparation activities and is 

typically integrated within the system development life cycle and capital planning

and budgeting processes. Once a certification agent is selected (or certification 

services procured), an execution plan for conducting the security certification and 

accreditation is prepared by the certification agent and approved by the information 

system owner, authorizing official, and senior agency information security officer. 

The execution plan contains specific tasks, milestones, and delivery schedule. This 

information can be included in a system development/change plan during the 

initiation phase of the system development life cycle and need not be repeated in a

separate plan of execution.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, a simplified

planning procedure is recommended. The information system owner estimates the level of 

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effort required for a self-assessment of the information system security controls. The 

authorizing official, senior agency information security officer, and independent

certification agent are not required to participate in the process.

REFERENCE: OMB Circular A-130, Appendix III. 

TASK 3: SYSTEM SECURITY PLAN ANALYSIS, UPDATE, AND ACCEPTANCE

The objective of the system security plan analysis, update, and acceptance task is to: (i) perform

an independent review of the FIPS 199 security categorization; (ii) obtain an independent analysis 

of the system security plan; (iii) update the system security plan as needed based on the results of 

the independent analysis; and (iv) obtain acceptance of the system security plan by the 

authorizing official and senior agency information security officer prior to conducting an 

assessment of the security controls in the information system. The completion of this task 

concludes the Initiation Phase of the security certification and accreditation process. 

SECURITY CATEGORIZATION REVIEW

SUBTASK 3.1: Review the FIPS 199 security categorization described in the system security plan to

determine if the assigned impact values with respect to the potential loss of 

confidentiality, integrity, and availability are consistent with agency’s actual mission 

requirements.

RESPONSIBILITY: Authorizing Official; Senior Agency Information Security Officer; 

Certification Agent.

GUIDANCE: FIPS 199 is used as part of an agency’s risk management program to help 

ensure that appropriate security controls are applied to each information system and 

that the controls are adequately assessed to determine the extent to which the controls

are implemented correctly, operating as intended, and producing the desired outcome 

with respect to meeting the system security requirements. The review of the security

categorization ensures that the information system owner has adequately reflected the 

importance (including criticality and sensitivity) of the information system in 

supporting the operations and assets of the agency. Independent review of the 

security categorization by the certification agent, authorizing official, and senior 

agency information security officer is performed as needed to ensure appropriate 

categorization. 

Supplemental Guidance for Low-Impact Systems: For low-impact systems, an independent

certification agent is not required to participate in the process.

REFERENCES: FIPS 199; NIST Special Publication 800-60, or equivalent. 

SYSTEM SECURITY PLAN ANALYSIS

SUBTASK 3.2: Analyze the system security plan to determine if the vulnerabilities in the information 

system and the resulting risk to agency operations, agency assets, or individuals are 

actually what the plan would produce, if implemented. 

RESPONSIBILITY: Authorizing Official; Senior Agency Information Security Officer; 

Certification Agent.

GUIDANCE: The system security plan provides an overview of the information system

security requirements and describes the security controls in place or planned for 

meeting those requirements. The independent review of the system security plan by 

the certification agent, authorizing official, and senior agency information security 

officer determines if the plan is complete and consistent with the requirements 

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document for the information system. The certification agent, authorizing official,

and senior agency information security officer also determine, at the level of analysis

possible only with available planning or operational documents and information from

the risk assessment, if the vulnerabilities in the information system and resulting 

agency-level risk appear to be correct and reasonable. Based on the results of this 

independent review and analysis, the certification agent, authorizing official and 

senior agency information security officer may recommend changes to the system

security plan. Whenever possible, these changes should be reflected in the

requirements document for the information system. 

Supplemental Guidance for Low-Impact Systems: For low-impact systems, a simplified

review process is recommended. The authorizing official and senior agency information 

security officer conduct a limited review of the system security plan to determine the 

validity of the plan. Minimal analysis is required. An independent certification agent is 

not required to participate in the process.

REFERENCE: NIST Special Publication 800-18, or equivalent. 

SYSTEM SECURITY PLAN UPDATE

SUBTASK 3.3: Update the system security plan based on the results of the independent analysis and 

recommendations of the certification agent, authorizing official, and senior agency

information security officer. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: The information system owner reviews the changes recommended by the 

certification agent, authorizing official, and senior agency information security

officer and consults with other agency representatives (e.g., information owner, 

information system security officer, or user representatives) prior to making any final 

modifications to the system security plan. The modifications to the system security 

plan may include any of the areas described in Task 1 (e.g., adjusting security

controls, changing vulnerabilities, or modifying the agency-level risk).

Supplemental Guidance for Low-Impact Systems: For low-impact systems, an independent

certification agent is not required to participate in the process.

REFERENCE: NIST Special Publication 800-18, or equivalent. 

SYSTEM SECURITY PLAN ACCEPTANCE

SUBTASK 3.4: Review the system security plan to determine if the risk to agency operations, agency

assets, or individuals is acceptable.

RESPONSIBILITY: Authorizing Official; Senior Agency Information Security Officer.

GUIDANCE: If the agency-level risk described in the system security plan (or risk 

assessment) is deemed unacceptable, the authorizing official and senior agency

information security officer send the plan back to the information system owner for 

appropriate action. If the agency-level risk described in the system security plan (or 

risk assessment) is deemed acceptable, the authorizing official and senior agency 

information security officer accept the plan. The acceptance of the system security 

plan and agency-level risk assessment represents an important milestone in the

security certification and accreditation of the information system. The authorizing 

official and senior agency information security officer, by accepting the system

security plan, are agreeing to the set of security controls proposed to meet the

security requirements for the information system. This agency-level agreement 

allows the security certification and accreditation process to advance to the next 

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phase (i.e., the actual assessment of the security controls). The acceptance of the 

system security plan also approves the level of effort and resources required to 

successfully complete the associated security certification and accreditation 

activities. 

Supplemental Guidance for Low-Impact Systems: For low-impact systems, a simplified

review process is recommended. The authorizing official and senior agency information 

security officer conduct a limited review of the system security plan to determine the 

acceptability of agency-level risk. Minimal analysis is required.

REFERENCE: NIST Special Publication 800-30, or equivalent. 

Key Milestone: 

The following questions should be answered before proceeding to the Security Certification Phase— 

− Does the FIPS 199 security category of the information system described in the system 

security plan appear to be correct?

− Have the resources required to successfully complete the security certification and

accreditation of the information system been identified and allocated?

− Does the risk to agency operations (including mission, functions, image, or reputation), 

agency assets, or individuals described in the system security plan appear to be correct?

− Having decided that the agency-level risk appears to be correct, would this risk be

acceptable?

3.2 SECURITY CERTIFICATION PHASE

The Security Certification Phase consists of two tasks: (i) security control assessment; and (ii) 

security certification documentation. The purpose of this phase is to determine the extent to 

which the security controls in the information system are implemented correctly, operating as 

intended, and producing the desired outcome with respect to meeting the security requirements 

for the system. This phase also addresses specific actions taken or planned to correct deficiencies 

in the security controls and to reduce or eliminate known vulnerabilities in the information 

system. Upon successful completion of this phase, the authorizing official will have the 

information needed from the security certification to determine the risk to agency operations, 

agency assets, or individuals—and thus will be able to render an appropriate security 

accreditation decision for the information system. 

TASK 4: SECURITY CONTROL ASSESSMENT

The objective of the security control assessment task is to: (i) prepare for the assessment of the 

security controls in the information system; (ii) conduct the assessment of the security controls; 

and (iii) document the results of the assessment. Preparation for security assessment involves 

gathering appropriate planning and supporting materials, system requirements and design 

documentation, security control implementation evidence, and results from previous security 

assessments, security reviews, or audits. Preparation also involves developing specific methods 

and procedures to assess the security controls in the information system. The certification agent,40

at the completion of this task, will be able to determine the extent to which the security controls 

 

40 The information system owner may assume the role of the independent certification agent when a self-assessment of 

the information system security controls is appropriate. The information system owner may also seek the assistance of 

other designated individuals (including contractors) in carrying out self-assessment activities.

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in the information system are implemented correctly, operating as intended, and producing the

desired outcome with respect to meeting the security requirements for the information system. 

The certification agent will also be in a position to make recommendations on corrective actions 

for security control deficiencies and offer advice to the information system owner and authorizing 

official on how the known vulnerabilities in the system translate into agency-level risk. 

DOCUMENTATION AND SUPPORTING MATERIALS

SUBTASK 4.1: Assemble any documentation and supporting materials necessary for the assessment 

of the security controls in the information system; if these documents include 

previous assessments of security controls, review the findings, results, and evidence.

RESPONSIBILITY: Information System Owner; Certification Agent.

GUIDANCE: The information system owner should assist the certification agent in

gathering all relevant documents and supporting materials from the agency that will

be required during the assessment of the security controls. Descriptive information 

about the information system is typically documented in the system identification 

section of the system security plan or in some cases, included by reference or as 

attachments to the plan. Supporting materials such as procedures, reports, logs, and 

records showing evidence of security control implementation should be identified as 

well. Assessing the security controls in an information system can be a very costly

and time-consuming process. In order to make the security certification and 

accreditation process as timely and cost-effective as possible, the reuse of previous 

evaluation results, when reasonable and appropriate, is strongly recommended. For 

example, a recent audit of an information system may have produced important 

information about the effectiveness of selected security controls. Another 

opportunity, as appropriate, to reuse previous assessment results comes from

programs that test and evaluate the security features of commercial information 

technology products. And finally, if prior assessment results from the system

developer are available, the certification agent, under appropriate circumstances may

incorporate those results into the security certification. Certification agents should 

maximize the use of previous assessment results in determining the extent to which 

the security controls are implemented correctly, operating as intended, and producing 

the desired outcome with respect to meeting the security requirements for the system.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, the information 

system owner may employ the services of the information system security officer or other 

designated individuals (including contractors) to assist in: (i) the assembly of

documentation and supporting materials necessary for a self-assessment of the

information system security controls; and (ii) the review of findings, results, and evidence

from previous assessments of the security controls. An independent certification agent is 

not required to participate in the process.

REFERENCES: Documents and supporting materials included or referenced in the

system security plan; NIST Special Publication 800-53A, or equivalent; audits; 

security certifications; security reviews; self-assessments; security test and evaluation

reports; privacy impact assessments; ISO/IEC 15408 (Common Criteria) validations;

FIPS 140-2 validations. 

METHODS AND PROCEDURES

SUBTASK 4.2: Select, or develop when needed, appropriate methods and procedures to assess the

management, operational, and technical security controls in the information system. 

RESPONSIBILITY: Certification Agent.

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GUIDANCE: In lieu of developing unique or specialized methods and procedures to

assess the security controls in the information system, certification agents should

consult NIST Special Publication 800-53A, which provides standardized methods 

and procedures for assessing the security controls listed in NIST Special Publication 

800-53. The certification agent, if so directed by the information system owner, 

authorizing official, or senior agency information security officer, can supplement 

these assessment methods and procedures. Assessment methods and procedures may

need to be created for those security controls employed by the agency that are not 

contained in NIST Special Publication 800-53. Additionally, assessment methods 

and procedures may need to be tailored for specific system implementations.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, the information 

system owner may employ the services of the information system security officer or other 

designated individuals (including contractors) to select or develop when needed, the

appropriate methods and procedures necessary to conduct a self-assessment of the

information system security controls. An independent certification agent is not required

to participate in the process.

REFERENCE: NIST Special Publication 800-53A, or equivalent. 

SECURITY ASSESSMENT

SUBTASK 4.3: Assess the management, operational, and technical security controls in the 

information system using methods and procedures selected or developed. 

RESPONSIBILITY: Certification Agent.

GUIDANCE: Security assessment determines the extent to which the security controls 

are implemented correctly, operating as intended, and producing the desired outcome 

with respect to meeting the security requirements for the system. The results of the

security assessment, including recommendations for correcting any deficiencies in

the security controls, are documented in the security assessment report.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, the information 

system owner may employ the services of the information system security officer or other 

designated individuals (including contractors) to conduct a self-assessment of the 

information system security controls. An independent certification agent is not required

to participate in the process.

REFERENCE: NIST Special Publication 800-53A, or equivalent. 

SECURITY ASSESSMENT REPORT

SUBTASK 4.4: Prepare the final security assessment report. 

RESPONSIBILITY: Certification Agent.

GUIDANCE: The security assessment report contains: (i) the results of the security

assessment (i.e., the determination of the extent to which the security controls are 

implemented correctly, operating as intended, and producing the desired outcome 

with respect to meeting the security requirements for the system); and (ii) 

recommendations for correcting deficiencies in the security controls and reducing or 

eliminating identified vulnerabilities. The security assessment report is part of the 

final accreditation package along with the updated system security plan and plan of 

action and milestones. The security assessment report is the certification agent’s 

statement regarding the security status of the information system. 

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Supplemental Guidance for Low-Impact Systems: For low-impact systems, the information 

system owner may employ the services of the information system security officer or other 

designated individuals (including contractors) to prepare the security assessment report

containing the results of the self-assessment of the information system security controls. 

The security assessment report can be a short and concise document synopsizing the selfassessment results and highlighting those areas that need further attention. An

independent certification agent is not required to participate in the process.

REFERENCE: NIST Special Publication 800-53A, or equivalent. 

TASK 5: SECURITY CERTIFICATION DOCUMENTATION

The objective of the security certification documentation task is to: (i) provide the certification 

findings and recommendations to the information system owner; (ii) update the system security 

plan as needed; (iii) prepare the plan of action and milestones; and (iv) assemble the accreditation 

package. The information system owner has an opportunity to reduce or eliminate vulnerabilities 

in the information system prior to the assembly and compilation of the accreditation package and 

submission to the authorizing official. This is accomplished by implementing corrective actions 

recommended by the certification agent. The certification agent should assess any security

controls modified, enhanced, or added during this process. The completion of this task concludes 

the Security Certification Phase. 

FINDINGS AND RECOMMENDATIONS

SUBTASK 5.1: Provide the information system owner with the security assessment report. 

RESPONSIBILITY: Certification Agent.

GUIDANCE: The information system owner relies on the security expertise and the

technical judgment of the certification agent to: (i) assess the security controls in the

information system; and (ii) provide specific recommendations on how to correct

deficiencies in the controls and reduce or eliminate identified vulnerabilities. The 

information system owner may choose to act on selected recommendations of the 

certification agent before the accreditation package is finalized if there are specific 

opportunities to correct deficiencies in security controls and reduce or eliminate 

vulnerabilities in the information system. To ensure effective allocation of resources 

agency-wide, any actions taken by the information system owner prior to the final 

accreditation decision should be coordinated with the authorizing official and senior 

agency information security officer. The certification agent assesses any changes 

made to the security controls in response to corrective actions by the information 

system owner and updates the assessment report, as appropriate.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, the information 

system security officer or other designated individuals (including contractors) provide 

the information system owner with the security assessment report containing the 

summarized results of the self-assessment of the information system security controls. An 

independent certification agent is not required to participate in the process.

REFERENCE: NIST Special Publication 800-30, or equivalent. 

SYSTEM SECURITY PLAN UPDATE

SUBTASK 5.2: Update the system security plan (and risk assessment) based on the results of the 

security assessment and any modifications to the security controls in the information 

system. 

RESPONSIBILITY: Information System Owner.

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GUIDANCE: The system security plan should reflect the actual state of the security 

controls after the security assessment and any modifications by the information 

system owner in addressing the recommendations for corrective actions from the 

certification agent. At the completion of the Security Certification Phase, the security

plan and risk assessment should contain an accurate list and description of the

security controls implemented and a list of identified vulnerabilities (i.e., controls not

implemented).

Supplemental Guidance for Low-Impact Systems: For low-impact systems, an independent

certification agent is not required to participate in the process.

REFERENCE: NIST Special Publication 800-18, or equivalent. 

PLAN OF ACTION AND MILESTONES PREPARATION

SUBTASK 5.3: Prepare the plan of action and milestones based on the results of the security

assessment. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: The plan of action and milestones document, one of the three key

documents in the security accreditation package, describes actions taken or planned

by the information system owner to correct deficiencies in the security controls and 

to address remaining vulnerabilities in the information system (i.e., reduce, eliminate,

or accept the vulnerabilities). The plan of actions and milestones document 

identifies: (i) the tasks needing to be accomplished; (ii) the resources required to

accomplish the elements of the plan; (iii) any milestones in meeting the tasks; and 

(iv) scheduled completion dates for the milestones. 

Supplemental Guidance for Low-Impact Systems: None.

REFERENCE: OMB Memorandum 02-01.

ACCREDITATION PACKAGE ASSEMBLY

SUBTASK 5.4: Assemble the final security accreditation package and submit to authorizing official.

RESPONSIBILITY: Information System Owner.

GUIDANCE: The information system owner is responsible for the assembly and 

compilation of the final security accreditation package with inputs from the 

information system security officer and the certification agent. The accreditation 

package contains: (i) the security assessment report from the certification agent 

providing the results of the independent assessment of the security controls and 

recommendations for corrective actions; (ii) the plan of action and milestones from

the information system owner indicating actions taken or planned to correct 

deficiencies in the controls and to reduce or eliminate vulnerabilities in the 

information system; and (iii) the updated system security plan with the latest copy of

the risk assessment. Certification agent input to the final accreditation package 

provides an unbiased and independent view of the extent to which the security

controls in the information system are implemented correctly, operating as intended, 

and producing the desired outcome with respect to meeting the system security

requirements. The information system owner may also wish to consult with other key

agency participants (e.g., the user representatives) prior to submitting the final 

accreditation package to the authorizing official. The authorizing official will use this

information during the Security Accreditation Phase to determine the risk to agency 

operations, agency assets, or individuals. The accreditation package can be submitted 

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in either paper or electronic form. The contents of the accreditation package should

be protected appropriately in accordance with agency policy.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, the security 

accreditation package consists of: (i) the updated system security plan; (ii) an 

abbreviated security assessment report (i.e., a brief summary of the self-assessment

results); and (iii) a plan of action and milestones.

REFERENCE: OMB Circular A-130, Appendix III. 

Key Milestone: 

The following questions should be answered before proceeding to the Security Accreditation Phase— 

− To what extent are the security controls in the information system implemented correctly, 

operating as intended, and producing the desired outcome with respect to meeting the

security requirements for the system?

− What specific actions have been taken or are planned to correct deficiencies in the security

controls and to reduce or eliminate known vulnerabilities in the information system?

3.3 SECURITY ACCREDITATION PHASE

The Security Accreditation Phase consists of two tasks: (i) security accreditation decision; and (ii) 

security accreditation documentation. The purpose of this phase is to determine if the remaining 

known vulnerabilities in the information system (after the implementation of an agreed-upon set 

of security controls) pose an acceptable level of risk to agency operations, agency assets, or 

individuals. Upon successful completion of this phase, the information system owner will have: 

(i) authorization to operate the information system; (ii) an interim authorization to operate the 

information system under specific terms and conditions; or (iii) denial of authorization to operate 

the information system. 

TASK 6: SECURITY ACCREDITATION DECISION

The objective of the security accreditation decision task is to: (i) determine the risk to agency

operations, agency assets, or individuals; and (ii) determine if the agency-level risk is acceptable. 

The authorizing official, working with information from the information system owner, 

information system security officer, and certification agent produced during the previous phase, 

has independent confirmation of the identified vulnerabilities in the information system and a list 

of planned or completed corrective actions to reduce or eliminate those vulnerabilities. It is this 

information that is used to determine the final risk to the agency and the acceptability of that risk. 

FINAL RISK DETERMINATION

SUBTASK 6.1: Determine the risk to agency operations, agency assets, or individuals based on the 

vulnerabilities in the information system and any planned or completed corrective

actions to reduce or eliminate those vulnerabilities. 

RESPONSIBILITY: Authorizing Official.

GUIDANCE: The authorizing official receives the final security accreditation package 

from the information system owner. The vulnerabilities in the information system

confirmed by the certification agent should be assessed to determine how those 

particular vulnerabilities translate into risk to agency operations, agency assets, or 

individuals. The authorizing official or designated representative should judge which 

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information system vulnerabilities are of greatest concern to the agency and which 

vulnerabilities can be tolerated without creating unreasonable agency-level risk. The

plan of action and milestones (i.e., actions taken or planned to correct deficiencies in 

the security controls and reduce or eliminate vulnerabilities) submitted by the 

information system owner should also be considered in determining the risk to the 

agency. The authorizing official may consult the information system owner, 

certification agent, or other agency officials before making the final risk

determination.

Supplemental Guidance for Low-Impact Systems: For low-impact systems, a simplified

process for risk determination is recommended. The level of effort by the authorizing 

official in determining risk should be minimal since the potential impact on agency 

operations, agency assets, and/or individuals has already been determined to be low. An

independent certification agent is not required to participate in the process.

REFERENCE: NIST Special Publication 800-30, or equivalent. 

RISK ACCEPTABILITY

SUBTASK 6.2: Determine if the risk to agency operations, agency assets, or individuals is acceptable 

and prepare the final security accreditation decision letter. 

RESPONSIBILITY: Authorizing Official.

GUIDANCE: The authorizing official should consider many factors when deciding if 

the risk to agency operations, agency assets, or individuals is acceptable. Balancing 

security considerations with mission and operational needs is paramount to achieving

an acceptable accreditation decision. The authorizing official renders an accreditation 

decision for the information system after reviewing all of the relevant information

and, where appropriate, consulting with key agency officials.

If, after assessing the results of the security certification, the authorizing official

deems that the agency-level risk is acceptable, an authorization to operate is issued. 

The information system is accredited without any restrictions or limitations on its 

operation. 

If, after assessing the results of the security certification, the authorizing official

deems that the agency-level risk is unacceptable, but there is an important missionrelated need to place the information system into operation, an interim authorization 

to operate may be issued. The interim authorization to operate is a limited 

authorization under specific terms and conditions including corrective actions to be

taken by the information system owner and a required timeframe for completion of 

those actions. A detailed plan of action and milestones should be submitted by the 

information system owner and approved by the authorizing official prior to the 

interim authorization to operate taking effect. The information system is not

accredited during the period of limited authorization to operate. The information 

system owner is responsible for completing the corrective actions identified in the 

plan of action and milestones and resubmitting an updated security accreditation 

package upon completion of those actions.

If, after assessing the results of the security certification, the authorizing official

deems that the agency-level risk is unacceptable, the information system is not

authorized for operation and thus is not accredited.

The authorizing official’s designated representative or administrative staff prepares 

the final security accreditation decision letter. The letter includes the accreditation 

decision, the rationale for the decision, the terms and conditions for information 

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system operation, and required corrective actions, if appropriate. The accreditation 

decision letter indicates to the information system owner whether the system is: (i) 

authorized to operate; (ii) authorized to operate on an interim basis under strict terms 

and conditions; or (iii) not authorized to operate. The supporting rationale provides 

the information system owner with the justification for the authorizing official’s 

decision. The terms and conditions for the authorization provide a description of any

limitations or restrictions placed on the operation of the information system that must 

be adhered to by the information system owner. The security accreditation letter is 

included in the final accreditation package. The contents of the accreditation package

should be protected appropriately in accordance with agency policy. 

Supplemental Guidance for Low-Impact Systems: For low-impact systems, a simplified

process for the determination of risk acceptability is recommended. The level of effort by 

the authorizing official in determining risk acceptability should be minimal since the 

potential impact on agency operations, agency assets, and/or individuals has already 

been determined to be low.

REFERENCE: OMB Circular A-130, Appendix III. 

TASK 7: SECURITY ACCREDITATION DOCUMENTATION

The objective of the security accreditation documentation task is to: (i) transmit the final security 

accreditation package to the appropriate individuals and organizations; and (ii) update the system

security plan with the latest information from the accreditation decision. The completion of this 

task concludes the Security Accreditation Phase of the security certification and accreditation 

process. 

SECURITY ACCREDITATION PACKAGE TRANSMISSION

SUBTASK 7.1: Provide copies of the final security accreditation package including the accreditation 

decision letter (in either paper or electronic form), to the information system owner 

and any other agency officials having an interest (i.e., need to know) in the security 

of the information system. 

RESPONSIBILITY: Authorizing Official. 

GUIDANCE: The security accreditation package including the accreditation decision 

letter is returned to the information system owner. Upon receipt of the security 

accreditation decision letter and accreditation package, the information system owner 

accepts the terms and conditions of the authorization. The original accreditation 

package is kept on file by the information system owner. The authorizing official and 

senior agency information security officer also retain copies of the decision letter and

accreditation package. The accreditation package contains important documents and 

as such, should be appropriately safeguarded and stored, whenever possible, in a

centralized agency filing system to ensure accessibility. The accreditation package

should also be readily available to auditors and oversight agencies upon request. The

accreditation package including all supporting documents, should be retained in

accordance with the agency’s records retention policy. 

Supplemental Guidance for Low-Impact Systems: None.

REFERENCE: OMB Circular A-130, Appendix III. 

SYSTEM SECURITY PLAN UPDATE

SUBTASK 7.2: Update the system security plan based on the final determination of risk to agency

operations, agency assets, or individuals. 

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RESPONSIBILITY: Information System Owner.

GUIDANCE: The system security plan should be updated to reflect any changes in the 

information system resulting from the Security Accreditation Phase. Any conditions

set forth in the accreditation decision should also be noted in the plan. It is expected 

that the changes to the system security plan at this phase in the security certification

and accreditation process would be minimal. 

Supplemental Guidance for Low-Impact Systems: None.

REFERENCE: NIST Special Publication 800-18, or equivalent. 

Key Milestone: 

The following questions should be answered before proceeding to the Continuous Monitoring Phase—

− How do the known vulnerabilities in the information system translate into agency-level risk—

that is, risk to agency operations, agency assets, or individuals?

− Is this agency-level risk acceptable?

3.4 CONTINOUS MONITORING PHASE

The Continuous Monitoring Phase consists of three tasks: (i) configuration management and 

control; (ii) security control monitoring; and (iii) status reporting and documentation. The 

purpose of this phase is to provide oversight and monitoring of the security controls in the 

information system on an ongoing basis and to inform the authorizing official when changes 

occur that may impact on the security of the system. The activities in this phase are performed 

continuously throughout the life cycle of the information system. Reaccreditation may be 

required because of specific changes to the information system or because federal or agency

policies require periodic reaccreditation of the information system. 

TASK 8: CONFIGURATION MANAGEMENT AND CONTROL

The objective of the configuration management and control task is to: (i) document the proposed 

or actual changes to the information system; and (ii) determine the impact of proposed or actual 

changes on the security of the system. An information system will typically be in a constant state 

of migration with upgrades to hardware, software, or firmware and possible modifications to the 

system environment. Documenting information system changes and assessing the potential 

impact on the security of the system on an ongoing basis is an essential aspect of maintaining the 

security accreditation. 

DOCUMENTATION OF INFORMATION SYSTEM CHANGES

SUBTASK 8.1: Using established agency configuration management and control procedures, 

document proposed or actual changes to the information system (including hardware, 

software, firmware, and surrounding environment). 

RESPONSIBILITY: Information System Owner.

GUIDANCE: An orderly and disciplined approach to managing, controlling, and 

documenting changes to an information system is critical to the continuous 

assessment of the security controls that protect the system. It is important to record

any relevant information about the specific proposed or actual changes to the 

hardware, firmware, or software such as version or release numbers, descriptions of

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new or modified features or capabilities, and security implementation guidance. It is

also important to record any changes to the information system environment such as 

modifications to the physical plant. The information system owner and information 

system security officer should use this information in assessing the potential security

impact of the proposed or actual changes to the information system. Significant

changes to the information system should not be undertaken prior to assessing the 

security impact of such changes.

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: Agency policies/procedures on configuration management and control.

SECURITY IMPACT ANALYSIS

SUBTASK 8.2: Analyze the proposed or actual changes to the information system (including

hardware, software, firmware, and surrounding environment) to determine the 

security impact of such changes. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: Changes to the information system may affect the security controls 

currently in place, produce new vulnerabilities in the system, or generate

requirements for new security controls that were not needed previously. If the results 

of the security impact analysis indicate that the proposed or actual changes to the 

information system will affect or have affected the security of the information 

system, corrective actions should be initiated and the plan of action and milestones

revised. The information system owner or information system security officer may 

wish to consult with the user representatives or other agency officials prior to

implementing any security-related changes to the information system. Conducting a 

security impact analysis is part of the ongoing assessment of risk within the agency. 

The level of effort (i.e., degree of rigor and formality) applied to the security impact 

analysis should be commensurate with the FIPS 199 security category of the 

information system (i.e., the level of effort increases as the potential impact on

agency operations, agency assets, or individuals increases).

Supplemental Guidance for Low-Impact Systems: None. 

REFERENCE: NIST Special Publication 800-30, or equivalent. 

TASK 9: SECURITY CONTROL MONITORING

The objective of the security control monitoring task is to: (i) select an appropriate set of security 

controls in the information system to be monitored; and (ii) assess the designated controls using 

methods and procedures selected by the information system owner. The continuous monitoring of 

security controls helps to identify potential security-related problems in the information system

that are not identified during the security impact analysis conducted as part of the configuration 

management and control process. 

SECURITY CONTROL SELECTION

SUBTASK 9.1: Select the security controls in the information system to be monitored on a 

continuous basis. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: The criteria established by the information system owner for selecting 

which security controls will be monitored should reflect the agency’s priorities and

importance of the information system to the agency. For example, certain security 

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controls may be considered more critical than other controls because of the potential 

impact on the information system if those controls were subverted or found to be 

ineffective. The security controls being monitored should be reviewed over time to 

ensure that a representative sample of controls is included in the ongoing security

assessments. The authorizing official and information system owner should agree on

the subset of security controls in the information system that should be monitored as

well as the frequency of such monitoring activity. The level of effort (i.e., degree of

rigor and formality) applied to the security control selection process should be 

commensurate with the FIPS 199 security category of the information system (i.e., 

the level of effort increases as the potential impact on agency operations, agency 

assets, or individuals increases).

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: FISMA; OMB Circular A-130, Appendix III; NIST Special 

Publication 800-53. 

SELECTED SECURITY CONTROL ASSESSMENT

SUBTASK 9.2: Assess an agreed-upon set of security controls in the information system to determine 

the extent to which the controls are implemented correctly, operating as intended, 

and producing the desired outcome with respect to meeting the security requirements 

for the system. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: The continuous monitoring of security controls can be accomplished in a 

variety of ways including security reviews, self-assessments, security testing and 

evaluation, or audits. The methods and procedures employed to assess the security

controls during the monitoring process are at the discretion of the information system

owner. In lieu of developing unique or specialized methods and procedures to assess 

the security controls in the information system, information system owners should 

consult NIST Special Publication 800-53A, which provides standardized assessment 

methods and procedures for the security controls listed in NIST Special Publication 

800-53. The monitoring process should be documented and available for review by

the authorizing official or senior agency information security officer, upon request. If

the results of the security assessment indicate that selected controls are less than 

effective in their application and are affecting the security of the information system, 

corrective actions should be initiated and the plan of action and milestones updated. 

The level of effort (i.e., degree of rigor and formality) applied to the assessment of 

security controls should be commensurate with the FIPS 199 security category of the 

information system (i.e., the level of effort increases as the potential impact on

agency operations, agency assets, or individuals increases).

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: FISMA; OMB Circular A-130, Appendix III; NIST Special 

Publication 800-53A. 

TASK 10: STATUS REPORTING AND DOCUMENTATION

The objective of the status reporting and documentation task is to: (i) update the system security 

plan to reflect the proposed or actual changes to the information system; (ii) update the plan of 

action and milestones based on the activities carried out during the continuous monitoring phase; 

and (iii) report the security status of the information system to the authorizing official and senior 

agency information security officer. The information in the security status reports (typically 

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conveyed through updated plans of action and milestones) should be used to determine the need 

for security reaccreditation and to satisfy FISMA reporting requirements. 

SYSTEM SECURITY PLAN UPDATE

SUBTASK 10.1: Update the system security plan based on the documented changes to the information 

system (including hardware, software, firmware, and surrounding environment) and

the results of the continuous monitoring process. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: The system security plan should contain the most up-to-date information 

about the information system. Changes to the information system should be reflected 

in the system security plan. The frequency of system security plan updates is at the 

discretion of the information system owner. The updates should occur at appropriate

intervals to capture significant changes to the information system, but not so 

frequently as to generate unnecessary paperwork. The Chief Information Officer,

senior agency information security officer, authorizing official, information system

owner, information system security officer, and certification agent will be using the

system security plan to guide any future security certification and accreditation 

activities, when required.

Supplemental Guidance for Low-Impact Systems: None.

REFERENCE: NIST Special Publication 800-18, or equivalent. 

PLAN OF ACTION AND MILESTONES UPDATE

SUBTASK 10.2: Update the plan of action and milestones based on the documented changes to the 

information system (including hardware, software, firmware, and surrounding 

environment) and the results of the continuous monitoring process. 

RESPONSIBILITY: Information System Owner.

GUIDANCE: The plan of action and milestones is used by the authorizing official to

monitor the progress in correcting deficiencies noted during the security certification. 

The plan of action and milestones should: (i) report progress made on the current

outstanding items listed in the plan; (ii) address vulnerabilities in the information

system discovered during the security impact analysis or security control monitoring;

and (iii) describe how the information system owner intends to address those 

vulnerabilities (i.e., reduce, eliminate, or accept the identified vulnerabilities). The 

frequency of the plan of action and milestones updates is at the discretion of the

information system owner. The updates should occur at appropriate intervals to

capture significant changes to the information system, but not so frequently as to

generate unnecessary paperwork. The Chief Information Officer, senior agency 

information security officer, authorizing official, information system owner, 

information system security officer, and certification agent will be using the plan of 

action and milestones to guide any future security certification and accreditation 

activities, when required.

Supplemental Guidance for Low-Impact Systems: None.

REFERENCE: OMB Memorandum 02-01.

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STATUS REPORTING

SUBTASK 10.3: Report the security status of the information system to the authorizing official and

senior agency information security officer.

RESPONSIBILITY: Information System Owner.

GUIDANCE: The security status report (which can be submitted in the form of an 

updated plan of action and milestones) should describe the continuous monitoring

activities employed by the information system owner. The security status report 

addresses vulnerabilities in the information system discovered during the security

certification, security impact analysis, and security control monitoring and how the 

information system owner intends to address those vulnerabilities (i.e., reduce,

eliminate, or accept the vulnerabilities). The frequency of security status reports is at

the discretion of the agency. The status reports should occur at appropriate intervals 

to transmit significant security-related information about the system, but not so

frequently as to generate unnecessary paperwork. The authorizing official and the

senior agency information system security officer should use the security status 

reports to determine if a security reaccreditation is necessary. The authorizing official

should notify the information system owner if there is a decision to require a 

reaccreditation of the information system. A decision to reaccredit the information 

system should begin, as in the original security accreditation, with the Initiation

Phase. The security status report should be marked and handled in accordance with

agency policy. At the discretion of the agency, the security status reports on agency 

information systems can be used to help satisfy the FISMA reporting requirement for 

documenting remedial actions for any security-related deficiencies.

Supplemental Guidance for Low-Impact Systems: None.

REFERENCES: FISMA; OMB Circular A-130, Appendix III. 

Key Milestone: 

The following questions should be answered before reinitiating the certification and accreditation process—

− Have any changes to the information system affected the security controls in the system or

introduced new vulnerabilities into the system? 

− If so, has the agency-level risk—that is, the risk to agency operations, agency assets, or

individuals been affected? or

− Has a specified time period passed requiring the information system to be reauthorized in

accordance with federal or agency policy?

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APPENDIX A

REFERENCES

LAWS, DIRECTIVES, POLICIES, STANDARDS, AND GUIDELINES 

1. Privacy Act of 1974 (Public Law 93-579), September 1975. 

2. Paperwork Reduction Act of 1995 (Public Law 104-13), May 1995. 

3. Information Technology Management Reform Act of 1996 (Public Law 104-106), August 

1996. 

4. Federal Information Security Management Act of 2002 (Public Law 107-347), December 

2002. 

5. OMB Circular A-130, Appendix III, Transmittal Memorandum #4, Management of 

Federal Information Resources, November 2000. 

6. Federal Information Processing Standards (FIPS) 199, Standards for Security 

Categorization of Federal Information and Information Systems, December 2003. 

7. Federal Information Processing Standards (FIPS) 200, Security Controls for Federal 

Information Systems (projected for publication December 2005). 

8. Committee for National Security Systems Instruction 4009, National Information 

Assurance Glossary, revised May 2003.

9. NIST Special Publication 800-18, Guide for Developing Security Plans for Information 

Technology Systems, December 1998. 

10. NIST Special Publication 800-26, Security Self-Assessment Guide for Information 

Technology Systems, November 2001. 

11. NIST Special Publication 800-30, Risk Management Guide for Information Technology 

Systems, January 2002. 

12. NIST Special Publication 800-34, Contingency Planning Guide for Information 

Technology Systems, June 2002. 

13. NIST Special Publication 800-47, Security Guide for Interconnecting Information 

Technology Systems, September 2002. 

14. NIST Special Publication 800-59, Guideline for Identifying an Information System as a 

National Security System, August 2003.

15. NIST Special Publication 800-50, Building an Information Technology Security Awareness 

and Training Program, October 2003. 

16. NIST Special Publication 800-64, Security Considerations in the Information System 

Development Life Cycle, October 2003. 

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17. NIST Special Publication 800-53, Recommended Security Controls for Federal 

Information Systems (Initial public draft), October 2003. 

18. NIST Special Publication 800-60, Guide for Mapping Information and Information Types 

to Security Objectives and Risk Levels (Second public draft), March 2004. 

19. NIST Special Publication 800-61, Computer Security Incident Handling Guide, January

2004. 

20. NIST Special Publication 800-53A, Guide for Assessing the Security Controls in Federal 

Information Systems (Initial public draft), Summer 2004. 

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APPENDIX B

GLOSSARY

COMMON TERMS AND DEFINITIONS 

Accreditation The official management decision given by a senior agency

official to authorize operation of an information system and to 

explicitly accept the risk to agency operations (including mission, 

functions, image, or reputation), agency assets, or individuals, 

based on the implementation of an agreed-upon set of security

controls. 

Accreditation Boundary All components of an information system to be accredited by an

authorizing official and excludes separately accredited systems, to 

which the information system is connected. Synonymous with the 

term security perimeter defined in CNSS Instruction 4009 and

DCID 6/3. 

Accreditation Package The evidence provided to the authorizing official to be used in the 

security accreditation decision process. Evidence includes, but is 

not limited to: (i) the system security plan; (ii) the assessment 

results from the security certification; and (iii) the plan of action 

and milestones. 

Accrediting Authority See Authorizing Official. 

Adequate Security 

[OMB Circular A-130,

Appendix III]

Security commensurate with the risk and the magnitude of harm

resulting from the loss, misuse, or unauthorized access to or 

modification of information. 

Agency See Executive Agency. 

Application 

[OMB Circular A-130,

Appendix III]

The use of information resources (information and information 

technology) to satisfy a specific set of user requirements. 

Assessment Method A focused activity or action employed by an assessor for 

evaluating a particular attribute of a security control. 

Assessment Procedure A set of activities or actions employed by an assessor to 

determine the extent to which a security control is implemented 

correctly, operating as intended, and producing the desired 

outcome with respect to meeting the security requirements for the 

system. 

Authenticity The property of being genuine and being able to be verified and 

trusted; confidence in the validity of a transmission, a message, or 

message originator. See authentication. 

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Authentication Verifying the identity of a user, process, or device, often as a 

prerequisite to allowing access to resources in an information 

system. 

Authorization See Accreditation. 

Authorize Processing See Accreditation. 

Authorizing Official Official with the authority to formally assume responsibility for

operating an information system at an acceptable level of risk to 

agency operations (including mission, functions, image, or 

reputation), agency assets, or individuals. 

Authorizing Official 

Designated Representative

Individual selected by an authorizing official to act on their behalf 

in coordinating and carrying out the necessary activities required 

during the security certification and accreditation of an 

information system. 

Availability

[44 U.S.C., Sec. 3542]

Ensuring timely and reliable access to and use of information. 

Designated Approving 

(Accrediting) Authority

See Authorizing Official. 

Certification Agent The individual, group, or organization responsible for conducting 

a security certification. 

Certification A comprehensive assessment of the management, operational, 

and technical security controls in an information system, made in 

support of security accreditation, to determine the extent to which 

the controls are implemented correctly, operating as intended, and 

producing the desired outcome with respect to meeting the 

security requirements for the system. 

Chief Information Officer

[44 U.S.C., Sec. 5125(b)]

Agency official responsible for: 

(i) Providing advice and other assistance to the head of the 

executive agency and other senior management personnel of the 

agency to ensure that information technology is acquired and 

information resources are managed in a manner that is consistent 

with laws, Executive Orders, directives, policies, regulations, and 

priorities established by the head of the agency; 

(ii) Developing, maintaining, and facilitating the implementation 

of a sound and integrated information technology architecture for 

the agency; and 

(iii) Promoting the effective and efficient design and operation of 

all major information resources management processes for the 

agency, including improvements to work processes of the agency.

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Common Security Control Security control that can be applied to one or more agency

information systems and has the following properties: (i) the 

development, implementation, and assessment of the control can be 

assigned to a responsible official or organizational element (other 

than the information system owner); and (ii) the results from the 

assessment of the control can be used to support the security

certification and accreditation processes of an agency information 

system where that control has been applied.

Confidentiality

[44 U.S.C., Sec. 3542]

Preserving authorized restrictions on information access and 

disclosure, including means for protecting personal privacy and

proprietary information. 

Countermeasures 

[CNSS Inst. 4009]

Actions, devices, procedures, techniques, or other measures that 

reduce the vulnerability of an information system. Synonymous 

with security controls and safeguards. 

Configuration Control 

[CNSS Inst. 4009]

Process for controlling modifications to hardware, firmware, 

software, and documentation to ensure the information system is 

protected against improper modifications prior to, during, and

after system implementation. 

Executive Agency

[41 U.S.C., Sec. 403] 

An executive department specified in 5 U.S.C., Sec. 101; a 

military department specified in 5 U.S.C., Sec. 102; an

independent establishment as defined in 5 U.S.C., Sec. 104(1); 

and a wholly owned Government corporation fully subject to the 

provisions of 31 U.S.C., Chapter 91. 

Federal Information 

System

[40 U.S.C., Sec. 11331] 

An information system used or operated by an executive agency, 

by a contractor of an executive agency, or by another 

organization on behalf of an executive agency. 

General Support System

[OMB Circular A-130,

Appendix III]

An interconnected set of information resources under the same

direct management control that shares common functionality. It 

normally includes hardware, software, information, data, 

applications, communications, and people. 

Information 

[FIPS 199] 

An instance of an information type. 

Information Owner 

[CNSS Inst. 4009]

Official with statutory or operational authority for specified 

information and responsibility for establishing the controls for its 

generation, collection, processing, dissemination, and disposal. 

Information Resources 

[44 U.S.C., Sec. 3502]

Information and related resources, such as personnel, equipment, 

funds, and information technology. 

Information Security

[44 U.S.C., Sec. 3542]

The protection of information and information systems from

unauthorized access, use, disclosure, disruption, modification, or 

destruction in order to provide confidentiality, integrity, and 

availability. 

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Information Security

Policy

[CNSS Inst. 4009]

Aggregate of directives, regulations, rules, and practices that 

prescribes how an organization manages, protects, and distributes 

information. 

Information System

[44 U.S.C., Sec. 3502]

[OMB Circular A-130,

Appendix III]

A discrete set of information resources organized for the 

collection, processing, maintenance, use, sharing, dissemination, 

or disposition of information. 

Information System Owner

(or Program Manager) 

[CNSS Inst. 4009, Adapted]

Official responsible for the overall procurement, development, 

integration, modification, or operation and maintenance of an 

information system. 

Information System

Security Officer 

[CNSS Inst. 4009, Adapted]

Individual responsible to the senior agency information security

officer, authorizing official, or information system owner for 

ensuring the appropriate operational security posture is 

maintained for an information system or program. 

Information Technology

[40 U.S.C., Sec. 1401]

Any equipment or interconnected system or subsystem of 

equipment that is used in the automatic acquisition, storage, 

manipulation, management, movement, control, display,

switching, interchange, transmission, or reception of data or 

information by the executive agency. For purposes of the 

preceding sentence, equipment is used by an executive agency if 

the equipment is used by the executive agency directly or is used 

by a contractor under a contract with the executive agency which:

(i) requires the use of such equipment; or (ii) requires the use, to a 

significant extent, of such equipment in the performance of a 

service or the furnishing of a product. The term information 

technology includes computers, ancillary equipment, software, 

firmware and similar procedures, services (including support

services), and related resources. 

Information Type 

[FIPS 199] 

A specific category of information (e.g., privacy, medical, 

proprietary, financial, investigative, contractor sensitive, security

management), defined by an organization or in some instances, 

by a specific law, Executive Order, directive, policy, or 

regulation. 

Integrity

[44 U.S.C., Sec. 3542]

Guarding against improper information modification or 

destruction, and includes ensuring information non-repudiation 

and authenticity. 

Major Application 

[OMB Circular A-130,

Appendix III]

An application that requires special attention to security due to 

the risk and magnitude of harm resulting from the loss, misuse, or 

unauthorized access to or modification of the information in the 

application. 

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Major Information System 

[FISMA] 

An information system that requires special management 

attention because of its importance to an agency mission; its high 

development, operating, or maintenance costs; or its significant 

role in the administration of agency programs, finances, property,

or other resources. 

Management Controls 

[NIST SP 800-18]

The security controls (i.e., safeguards or countermeasures) for an 

information system that focus on the management of risk and the 

management of information system security. 

Minor Application An application, other than a major application, that requires 

attention to security due to the risk and magnitude of harm

resulting from the loss, misuse, or unauthorized access to or 

modification of the information in the application. Minor 

applications are typically included as part of a general support 

system. 

National Security

Information 

Information that has been determined pursuant to Executive 

Order 12958 as amended by Executive Order 13292, or any

predecessor order, or by the Atomic Energy Act of 1954, as 

amended, to require protection against unauthorized disclosure 

and is marked to indicate its classified status. 

National Security System

[44 U.S.C., Sec. 3542]

Any information system (including any telecommunications 

system) used or operated by an agency or by a contractor of an 

agency, or other organization on behalf of an agency— (i) the 

function, operation, or use of which involves intelligence 

activities; involves cryptologic activities related to national 

security; involves command and control of military forces; 

involves equipment that is an integral part of a weapon or 

weapons system; or is critical to the direct fulfillment of military

or intelligence missions (excluding a system that is to be used for 

routine administrative and business applications, for example, 

payroll, finance, logistics, and personnel management 

applications); or, (ii) is protected at all times by procedures 

established for information that have been specifically authorized 

under criteria established by an Executive Order or an Act of 

Congress to be kept classified in the interest of national defense 

or foreign policy.

Non-repudiation 

[CNSS Inst. 4009]

Assurance that the sender of information is provided with proof 

of delivery and the recipient is provided with proof of the 

sender’s identity, so neither can later deny having processed the 

information. 

Operational Controls 

[NIST SP 800-18]

The security controls (i.e., safeguards or countermeasures) for an 

information system that primarily are implemented and executed 

by people (as opposed to systems). 

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Plan of Action and 

Milestones 

[OMB Memorandum 02-01]

A document that identifies tasks needing to be accomplished. It 

details resources required to accomplish the elements of the plan, 

any milestones in meeting the tasks, and scheduled completion 

dates for the milestones. 

Potential Impact 

[FIPS 199] 

Low: The loss of confidentiality, integrity, or availability could 

be expected to have a limited adverse effect on organizational 

operations, organizational assets, or individuals. 

Moderate: The loss of confidentiality, integrity, or availability

could be expected to have a serious adverse effect on 

organizational operations, organizational assets, or individuals. 

High: The loss of confidentiality, integrity, or availability could 

be expected to have a severe or catastrophic adverse effect on 

organizational operations, organizational assets, or individuals. 

Risk 

[NIST SP 800-30]

The level of impact on agency operations (including mission, 

functions, image, or reputation), agency assets, or individuals 

resulting from the operation of an information system given the 

potential impact of a threat and the likelihood of that threat 

occurring. 

Risk Assessment 

[NIST SP 800-30]

The process of identifying risks to agency operations (including 

mission, functions, image, or reputation), agency assets, or 

individuals by determining the probability of occurrence, the 

resulting impact, and additional security controls that would 

mitigate this impact. Part of risk management, synonymous with 

risk analysis, and incorporates threat and vulnerability analyses. 

Risk Management 

[NIST SP 800-30]

The process of managing risks to agency operations (including 

mission, functions, image, or reputation), agency assets, or 

individuals resulting from the operation of an information system. 

It includes risk assessment; cost-benefit analysis; the selection, 

implementation, and assessment of security controls; and the 

formal authorization to operate the system. The process considers 

effectiveness, efficiency, and constraints due to laws, directives, 

policies, or regulations. 

Safeguards 

[CNSS Inst. 4009, Adapted]

Protective measures prescribed to meet the security requirements 

(i.e., confidentiality, integrity, and availability) specified for an 

information system. Safeguards may include security features, 

management constraints, personnel security, and security of 

physical structures, areas, and devices. Synonymous with security

controls and countermeasures. 

Security Authorization See Accreditation. 

Security Accreditation See Accreditation. 

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Security Category

[FIPS 199] 

The characterization of information or an information system

based on an assessment of the potential impact that a loss of 

confidentiality, integrity, or availability of such information or 

information system would have on organizational operations, 

organizational assets, or individuals. 

Security Controls 

[FIPS 199] 

The management, operational, and technical controls (i.e., 

safeguards or countermeasures) prescribed for an information 

system to protect the confidentiality, integrity, and availability of 

the system and its information. 

Security Impact Analysis The analysis conducted by an agency official, often during the 

continuous monitoring phase of the security certification and 

accreditation process, to determine the extent to which changes to 

the information system have affected the security posture of the 

system. 

Security Objective Confidentiality, integrity, or availability. 

Security Plan See System Security Plan. 

Security Requirements 

[CNSS Inst. 4009, Adapted]

Types and levels of protection necessary for equipment, data, 

information, applications, and facilities to meet laws, Executive 

Orders, directives, policies, or regulations. 

Senior Agency 

Information Security 

Officer 

Official responsible for carrying out the Chief Information 

Officer responsibilities under FISMA and serving as the Chief 

Information Officer’s primary liaison to the agency’s authorizing 

officials, information system owners, and information system

security officers. 

Subsystem A major subdivision or component of an information system

consisting of information, information technology, and personnel 

that performs one or more specific functions. 

System See Information System. 

System-specific Security

Control 

A security control for an information system that has not been 

designated as a common security control. 

System Security Plan 

[NIST SP 800-18]

Formal document that provides an overview of the security 

requirements for the information system and describes the 

security controls in place or planned for meeting those 

requirements. 

Technical Controls 

[NIST SP 800-18, Adapted]

The security controls (i.e., safeguards or countermeasures) for an 

information system that are primarily implemented and executed 

by the information system through mechanisms contained in the 

hardware, software, or firmware components of the system. 

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Threat 

[CNSS Inst. 4009, Adapted]

Any circumstance or event with the potential to adversely impact 

agency operations (including mission, functions, image, or 

reputation), agency assets, or individuals through an information 

system via unauthorized access, destruction, disclosure, 

modification of information, and/or denial of service. 

Threat Agent See Threat Source. 

Threat Assessment 

[CNSS Inst. 4009]

Formal description and evaluation of threat to an information 

system. 

Threat Source 

[NIST SP 800-30]

Either: (i) intent and method targeted at the intentional 

exploitation of a vulnerability; or (ii) a situation and method that 

may accidentally trigger a vulnerability. Synonymous with threat 

agent. 

User Representative An individual that represents the operational interests of the user 

community and serves as the liaison for that community 

throughout the system development life cycle of the information 

system. 

Vulnerability 

[CNSS Inst. 4009, Adapted]

Weakness in an information system, system security procedures, 

internal controls, or implementation that could be exploited or 

triggered by a threat source. 

Vulnerability Assessment 

[CNSS Inst. 4009]

Formal description and evaluation of the vulnerabilities in an 

information system. 

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APPENDIX C

ACRONYMS

COMMON ABBREVIATIONS 

CIO Chief Information Officer

CNSS Committee for National Security Systems 

COTS Commercial Off The Shelf 

DCID Director of Central Intelligence Directive 

FIPS Federal Information Processing Standard(s) 

FISMA Federal Information Security Management Act 

MOA Memorandum of Agreement 

MOU Memorandum of Understanding 

NIAP National Information Assurance Partnership 

NIST National Institute of Standards and Technology 

NSA National Security Agency

OMB Office of Management and Budget 

U.S.C. United States Code 

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APPENDIX D

SUMMARY OF PHASES AND RESPONSIBILITIES

LISTING BY SECURITY CERTIFICATION AND ACCREDITATION TASK AND SUBTASK 

PHASES, TASKS, AND SUBTASKS RESPONSIBILITY 

Initiation Phase 

 Task 1: Preparation

Subtask 1.1: Information System Description Information System Owner 

Subtask 1.2: Security Categorization Information System Owner 

Subtask 1.3: Threat Identification Information System Owner 

Subtask 1.4: Vulnerability Identification Information System Owner 

Subtask 1.5: Security Control Identification Information System Owner 

Subtask 1.6: Initial Risk Determination Information System Owner 

Task 2: Notification and Resource Identification

Subtask 2.1: Notification Information System Owner 

Subtask 2.2: Planning and Resources Authorizing Official 

Senior Agency Information Security Officer 

Information System Owner 

Certification Agent 

Task 3: System Security Plan Analysis, Update, and Acceptance 

Subtask 3.1: Security Categorization Review Authorizing Official 

Senior Agency Information Security Officer 

Certification Agent 

Subtask 3.2: System Security Plan Analysis Authorizing Official 

Senior Agency Information Security Officer 

Certification Agent 

Subtask 3.3: System Security Plan Update Information System Owner 

Subtask 3.4: System Security Plan Acceptance Authorizing Official 

Senior Agency Information Security Officer 

Security Certification Phase 

Task 4: Security Control Assessment 

Subtask 4.1: Documentation and Supporting Materials Information System Owner 

Certification Agent 

Subtask 4.2: Methods and Procedures Certification Agent 

Subtask 4.3: Security Assessment Certification Agent 

Subtask 4.4: Security Assessment Report Certification Agent 

Task 5: Security Certification Documentation

Subtask 5.1: Findings and Recommendations Certification Agent

Subtask 5.2: System Security Plan Update Information System Owner 

Subtask 5.3: Plan of Action and Milestones Preparation Information System Owner 

Subtask 5.4: Accreditation Package Assembly Information System Owner 

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PHASES, TASKS, AND SUBTASKS RESPONSIBILITY 

Security Accreditation Phase 

Task 6: Security Accreditation Decision

Subtask 6.1: Final Risk Determination Authorizing Official

Subtask 6.2: Risk Acceptability Authorizing Official

Task 7: Security Accreditation Documentation

Subtask 7.1: Security Accreditation Package Transmission Authorizing Official 

Subtask 7.2: System Security Plan Update Information System Owner 

Continuous Monitoring Phase 

Task 8: Configuration Management and Control 

Subtask 8.1: Documentation of Information System Changes Information System Owner 

Subtask 8.2: Security Impact Analysis Information System Owner 

Task 9: Security Control Monitoring

Subtask 9.1: Security Control Selection Information System Owner 

Subtask 9.2: Selected Security Control Assessment Information System Owner 

Task 10: Status Reporting and Documentation

Subtask 10.1: System Security Plan Update Information System Owner 

Subtask 10.2: Plan of Action and Milestones Update Information System Owner 

Subtask 10.3: Status Reporting Information System Owner 

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APPENDIX E

SAMPLE TRANSMITTAL AND DECISION LETTERS

AUTHORIZATION, INTERIM AUTHORIZATION, AND DENIAL OF AUTHORIZATION 

Security Accreditation Package Transmittal Letter 

From: Information System Owner Date: 

Thru: Senior Agency Information Security Officer

To: Authorizing Official 

Subject: Security Accreditation Package for [INFORMATION SYSTEM] 

A security certification of the [INFORMATION SYSTEM] and its constituent subsystem-level 

components (if applicable) located at [LOCATION] has been conducted in accordance with Office of 

Management and Budget Circular A-130, Appendix III, Security of Federal Automated 

Information Resources; NIST Special Publication 800-37, Guide for the Security Certification 

and Accreditation of Federal Information Systems; and the [AGENCY] policy on security

accreditation. The attached security accreditation package contains: (i) current system security 

plan; (ii) security assessment report; and (iii) plan of action and milestones. 

The security controls listed in the system security plan have been assessed by [CERTIFICATION

AGENT] using the assessment methods and procedures described in the security assessment report 

to determine the extent to which the controls are implemented correctly, operating as intended, 

and producing the desired outcome with respect to meeting the security requirements for the 

system. The plan of action and milestones describes the corrective measures that have been 

implemented or are planned to address any deficiencies in the security controls for the 

information system and to reduce or eliminate known vulnerabilities. 

Signature 

Title 

Enclosures 

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Security Accreditation Decision Letter (Authorization to Operate) 

From: Authorizing Official Date: 

Thru: Senior Agency Information Security Officer

To: Information System Owner 

Subject: Security Accreditation Decision for [INFORMATION SYSTEM] 

After reviewing the results of the security certification of the [INFORMATION SYSTEM] and its 

constituent system-level components (if applicable) located at [LOCATION] and the supporting 

evidence provided in the associated security accreditation package (including the current system

security plan, the security assessment report, and the plan of action and milestones), I have 

determined that the risk to agency operations, agency assets, or individuals resulting from the 

operation of the information system is acceptable. Accordingly, I am issuing an authorization to 

operate the information system in its existing operating environment. The information system is 

accredited without any significant restrictions or limitations. This security accreditation is my

formal declaration that adequate security controls have been implemented in the information 

system and that a satisfactory level of security is present in the system. 

The security accreditation of the information system will remain in effect as long as: (i) the 

required security status reports for the system are submitted to this office every [TIME PERIOD]; (ii) 

the vulnerabilities reported during the continuous monitoring process do not result in additional 

agency-level risk which is deemed unacceptable; and (iii) the system has not exceeded the 

maximum allowable time period between security accreditations in accordance with federal or 

agency policy. 

A copy of this letter with all supporting security certification and accreditation documentation 

should be retained in accordance with the agency’s record retention schedule. 

Signature 

Title 

Enclosures 

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Security Accreditation Decision Letter (Interim Authorization to Operate) 

From: Authorizing Official Date: 

Thru: Senior Agency Information Security Officer

To: Information System Owner 

Subject: Security Accreditation Decision for [INFORMATION SYSTEM] 

After reviewing the results of the security certification of the [INFORMATION SYSTEM] and its 

constituent system-level components (if applicable) located at [LOCATION] and the supporting 

evidence provided in the associated security accreditation package (including the current system

security plan, the security assessment report, and the plan of action and milestones), I have 

determined that the risk to agency operations, agency assets, or individuals resulting from the 

operation of the information system is not acceptable. However, I have also determined that there 

is an overarching need to place the information system into operation or continue its operation 

due to mission necessity. Accordingly, I am issuing an interim authorization to operate the 

information system in its existing operating environment. An interim authorization is a limited 

authorization to operate the information system under specific terms and conditions and 

acknowledges greater agency-level risk for a limited period of time. The information system is 

not considered accredited during the period of limited authorization to operate. The terms and 

conditions of this limited authorization are described in Attachment A. 

A process must be established immediately to monitor the effectiveness of the security controls in 

the information system during the period of limited authorization. Monitoring activities should 

focus on the specific areas of concern identified during the security certification. Significant 

changes in the security state of the information system during the period of limited authorization 

should be reported immediately.

This interim authorization to operate the information system is valid for [TIME PERIOD]. The 

limited authorization will remain in effect during that time period as long as: (i) the required 

security status reports for the system are submitted to this office every [TIME PERIOD]; (ii) the 

vulnerabilities reported during the continuous monitoring process do not result in additional 

agency-level risk which is deemed unacceptable; and (iii) continued progress is being made in

reducing or eliminating vulnerabilities in the information system in accordance with the plan of 

action and milestones. At the end of the period of limited authorization, the information system

must be either authorized to operate or the authorization for further operation will be denied. 

Renewals or extensions to this interim authorization to operate will be granted only under the 

most extenuating of circumstances. This office will monitor the plan of action and milestones 

submitted with the accreditation package during the period of limited authorization. 

A copy of this letter with all supporting security certification and accreditation documentation 

should be retained in accordance with the agency’s record retention schedule. 

Signature 

Title 

Enclosures 

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Security Accreditation Decision Letter (Denial of Authorization to Operate) 

From: Authorizing Official Date: 

Thru: Senior Agency Information Security Officer

To: Information System Owner 

Subject: Security Accreditation Decision for [INFORMATION SYSTEM] 

After reviewing the results of the security certification of the [INFORMATION SYSTEM] and its 

constituent system-level components (if applicable) located at [LOCATION] and the supporting 

evidence provided in the associated security accreditation package (including the current system

security plan, the security assessment report, and the plan of action and milestones), I have 

determined that the risk to agency operations, agency assets, or individuals resulting from the 

operation of the information system is unacceptable. Accordingly, I am issuing a denial of 

authorization to operate the information system in its existing operating environment. The 

information system is not accredited and [MAY NOT BE PLACED INTO OPERATION or ALL CURRENT 

OPERATIONS MUST BE HALTED]. Failure to receive an authorization to operate the information 

system indicates that there are major deficiencies in the security controls in the system and that a 

satisfactory level of security is not present in the system at this time. 

The plan of action and milestones should be revised immediately to ensure that proactive 

measures are taken to correct the security deficiencies in the information system. The security

certification should be repeated at the earliest opportunity to determine the effectiveness of the 

security controls in the information system after the reduction or elimination of identified 

vulnerabilities. 

A copy of this letter with all supporting security certification and accreditation documentation 

should be retained in accordance with the agency’s record retention schedule. 

Signature 

Title 

Enclosures 

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