Processing the CMS-855O Medicare 
Enrollment Application  Enrollment for 
Eligible Ordering, Certifying Physicians, 
and Other Eligible Professionals 
  Disclaimer: The information contained in this guide is to assist providers/suppliers in completing 
the Form CMS-855O application and MACs in processing Form CMS-855O application.   
 
 
 
Contents 
 
General Information ........................................................................................................................................... 3 
Section 1: Basic Information ............................................................................................................................... 4 
A - Reason for Submitting this Application ..................................................................................................... 5 
B - Reason you are Enrolling to Order and  Certify .......................................................................................... 5 
Section 2: Identifying Information ..................................................................................................................... 6 
A  Personal Information ................................................................................................................................ 6 
B  Educational Information ........................................................................................................................... 6 
C  License/Certification/Registration Information ........................................................................................ 7 
Section 3:  Final Adverse Legal Action ................................................................................................................ 8 
Section 4: Medical Specialty Information ........................................................................................................... 8 
A  Physician Specialty .................................................................................................................................... 8 
B  Eligible Professional or Other Eligible Professional or Other Non-Physician Type Specialty Type ........... 8 
Section 5:  Important Address Information ........................................................................................................ 9 
Section 6:  Contact Person Information .............................................................................................................. 9 
Section 7:  Penalties for Falsifying Information on this Application ................................................................. 10 
Section 8: Certification Statement and Signature ............................................................................................ 10 
  Disclaimer: The information contained in this guide is to assist providers/suppliers in completing 
the Form CMS-855O application and MACs in processing Form CMS-855O application.   
 
General Information 
 
Most physicians and eligible professionals (as defined in section 1848(K)(3)(B) of the Social 
Security Act) enroll in the Medicare program to be reimbursed for the covered services they 
furnish to Medicare beneficiaries. However, with the implementation of Section 6405 of the 
Affordable Care Act, CMS requires certain physicians and eligible professionals (hereafter 
referred to as providers) to enroll in the Medicare program for the sole purpose of ordering or 
certifying items or services for Medicare beneficiaries. These providers do not and will not send 
claims to a Medicare Administrative MAC (MAC) for the services they furnish. The providers 
who may enroll in Medicare solely for the purpose of ordering and certifying include those who 
are: 
 
  Doctors of Medicine or Osteopathy 
  Doctors of Dental Medicine 
  Doctors of Dental Surgery 
  Doctors of Podiatric Medicine 
  Doctors of Optometry 
  Physician Assistants 
  Certified Clinical Nurse Specialists 
  Nurse Practitioners 
  Clinical Psychologists 
  Certified Nurse Midwifes 
  Clinical Social Workers 
  Licensed Residents (as defined in 42 C.F.R. section 413.75(b)) in an approved 
medical residency program 
  Retired Physicians who are licensed 
 
These providers can enroll for the sole purpose of ordering or certifying items or services for 
Medicare beneficiaries by completing the Form CMS-855O via paper or the Internet-based 
Provider Enrollment, Chain and Ownership System (PECOS) process. To obtain additional 
information on Internet-based PECOS, refer to http://www.cms.gov/Medicare/Provider-
Enrollment-and- Certification/MedicareProviderSupEnroll/InternetbasedPECOS.html. 
 
In lieu of Internet-based PECOS, the most current version of the Form CMS-855O (January 2017) 
shall be completed by the providers. If an outdated version of the application is submitted, the 
MACs shall return any Form CMS-855O applications submitted on the previous version (01/13) to 
the provider/supplier with a letter explaining the CMS-855O has been updated and the supplier 
must submit the current version of the CMS-855O (01/17). To obtain the current version of the 
form, refer to http://www.cms.gov/MedicareProviderSupEnroll. 
 
It is important to observe that providers that complete the Form CMS-855O do not and will not 
send claims to their MAC for services they furnish. These providers are not given Medicare 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11  billing privileges for the purpose of submitting claims to Medicare directly for services that they 
furnish to beneficiaries. 
 
The ordering and certifying effective date is the date the MAC receives the CMS-855O 
application. 
 
NOTE: Only one Form CMS-855O submission is required which will allow the provider to 
order, certify nationwide.  Multiple Form CMS-855O submissions are not required. The provider 
need not submit a Form CMS-460, a Form CMS-588, or an application fee with his or her Form 
CMS-855O. 
 
Providers shall submit their CMS-855O applications to the MAC that serves there geographic 
jurisdiction.  To find out the MAC that serves your jurisdiction, refer 
to https://www.cms.gov/Medicare/Provider-Enrollment-and-
Certification/MedicareProviderSupEnroll/Downloads/contact_list.pdf.  
 
However, since the CMS-855O is a national enrollment, providers who relocate to another state 
are not required to dis-enroll in the current state and re-enroll in the new state.  The MAC that 
maintains the CMS-855O enrollment in the Provider Enrollment Chain and Ownership System 
(PECOS) is responsible for processing the change of information, even if the provider is 
relocating to a state outside of their jurisdiction.  If any new licenses and/or certifications are 
obtained as a result of the providers relocation, the MACs shall ensure that the updated 
information is captured in the providers enrollment record. 
 
Once enrolled, the provider will be listed on a CMS database located at http://Data.cms.gov and 
will be deemed eligible to order and certify services and items for Medicare beneficiaries. 
 
If the providers Form CMS-855O has been approved and he/she later wants to obtain Medicare 
billing privileges, the provider must complete the Form CMS-855I in order to receive Medicare 
billing privileges. 
 
If the provider has an approved Opt Out affidavit and now wants to be ordering/certifying only, 
the provider will need to notify the MAC they wish to term the Opt Out status, prior to 
completing the CMS-855O.  Please be aware that the Opt Out period must be exhausted prior to 
enrollment. 
 
Section 1: Basic Information 
 
All information on the Form CMS-855O is required with the exception of fields specifically 
marked as optional. 
 
The following general alternatives are applicable to all sections of the Form CMS-855O, 
unless otherwise specified: 
 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11  1.  Information Disclosed Elsewhere - If a data element on the suppliers Form CMS-855O 
application is missing but the information is disclosed (1) elsewhere on the application or 
(2) in the supporting documentation submitted with the application, the MAC need not 
obtain the missing data via an updated Form CMS-855O page and a newly-signed 
certification statement; no further development  not even by telephone  is required. The 
following information, however, must be furnished in the appropriate section(s) of the 
Form CMS- 855O, even if the data is identified elsewhere on the form or in the supporting 
documentation: 
 
a. Any final adverse action data requested in section 3 
b. Legal names 
c. Social Security Number (SSN) 
d. NPI-legacy number combinations in section 2 (if applicable) 
A - Reason for Submitting this Application 
This section identifies the reason for the application submission. With the exception of the 
voluntarily withdrawing checkbox, any blank checkboxes in Section 1 can be verified through 
any means chosen by the MAC (e.g., e-mail, telephone, fax). 
  You are enrolling for the sole purpose of ordering/certifying  
  Provider checks this box if he/she is enrolling for the sole purpose of ordering 
o
and certifying items and/or services to beneficiaries in the Medicare program. 
  All sections of the application must be completed. 
o
 
  You are currently enrolled solely to order and certify and are updating your 
information 
  Provider checks this box if he/she is enrolled for the sole purpose of ordering and 
o
certifying items and/or services to beneficiaries in the Medicare program but is 
making a change in their enrollment information. 
  Section 2A must be completed with the physician or eligible professionals 
o
personal information and all other applicable sections, including section 8. 
 
 
  You are voluntarily withdrawing your Medicare enrollment to solely order and 
certify  
  Provider checks this box if he/she no longer wants to be enrolled for the 
o
sole purpose of ordering and certifying items and/or services to 
beneficiaries in the Medicare program. 
  Section 2A must be completed with the physician or eligible professionals 
o
personal information and all other applicable sections, including section 8. 
B - Reason you are Enrolling Solely to Order or Certify 
This section identifies the reason the provider is registering solely to order, certify. Only one 
reason should be checked. If a reason is not identified, the MAC can verify the information 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11  through any means chosen (e.g., e-mail, telephone, fax). 
 
Section 2: Identifying Information  
A  Personal Information 
The provider must provide all applicable information in this section. The MAC shall verify all 
of the information on the Form CMS-855O to include: 
 
  The name, date of birth and social security number coincides with the information on 
the individuals Social Security record. This information will be validated against the 
Social Security Administration (SSA). 
  The Medicare Identification Number (or PTAN) (if issued) of the provider should be 
listed in the Medicare Identification Number field. If the provider is submitting an initial 
enrollment application a PTAN need not be listed; the provider can enter the word n/a 
in this field or leave the field blank since providers who enroll to order and certify will 
not be assigned a PTAN. 
  NPI of the provider should be reflected in the National Provider Identifier field; it 
should match the information provided to the National Plan and Provider Enumeration 
System (NPPES) and must be a Type 1 NPI. NPPES can be accessed by visiting 
https://nppes.cms.hhs.gov/NPPES/Welcome.do. 
  If any of the required information is not supplied, the MAC shall send a development 
request to the provider/contact person to obtain the missing data except for Type of Other 
Name and Gender which can be captured orally. 
  Reviewing the Medicare Exclusion Database (MED) and System for Award 
Management (SAM) to ensure that the provider is not excluded or debarred. 
 
If, at any time during the verification process, the MAC needs additional or clarifying information 
from the provider, it shall follow existing CMS instructions for obtaining said data (e.g., sending a 
developmental letter). The information must be furnished to the MAC within 30 calendar days of 
the MACs request. 
B  Educational Information 
 
The provider must provide their Medical School/Professional School information in this section 
along with their year of graduation.  If the Form CMS-855O lacks the Medical or Professional 
School and/or the year of graduation, but the information is disclosed in the supporting 
documentation submitted with the application or already exists in PECOS, no further development 
is needed by the MAC. 
 
If the information is not given, found in the supporting documentation or PECOS, the MAC 
shall send a development request to the provider/contact person to obtain the missing data. To 
the maximum extent possible, the MAC may use means other than the providers submission 
of documentation- such as a State or school Web site - to verify the Medical 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11  School/Professional School information. 
C  License/Certification/Registration Information 
 
The provider shall complete this section listing their applicable license, certifications and 
registrations. The MAC shall verify that the provider meets the requirements for his/her supplier 
type, is licensed and/or certified to furnish services and is of a supplier type that can legally order 
or certify. The only licenses that must be submitted with the application are those required by 
Medicare or the state to function as the supplier type in question. 
 
When processing a non-physician practitioners (NPP) application, the MAC need not 
automatically request a copy of the NPPs degree or diploma (if it is not submitted) if his or her 
education can be verified through other authorized means; requesting a copy of the degree or 
diploma should only be done if educational information cannot otherwise be verified.  If the 
provider submits a copy of the applicable license, certification, registration or degree but fails to 
complete the applicable section of Form CMS-855O, the section need not be completed if the data 
in question can be verified on the license/certification/registration itself or via any of the 
mechanisms at the MACs disposal. 
 
If the MAC is aware that a particular state does not require license/certification and the Not 
Applicable boxes are not checked in Section 2C, no further development is needed. 
 
MACs shall process form CMS-855O applications where the provider has relocated to another 
state. Since the form CMS-855O is a national enrollment, providers who relocate to another state 
are not required to dis-enroll in the current state and re-enroll in the new state. The MAC that 
maintains the form CMS-855O enrollment in the Provider Enrollment Chain and Ownership 
System (PECOS) is responsible for processing the change of information, even if the provider is 
relocating to a state outside of their jurisdiction. If any new licenses and/or certifications are 
obtained as a result of the providers relocation, the MACs shall ensure that the updated 
information is captured in the providers enrollment record. 
 
The provider shall enter their Drug Enforcement Agency (DEA) Registration Information, if 
applicable.  If the DEA fields are not completed at all on the application, meaning no information 
was entered into this section, MACs shall assume that the DEA information is not applicable and 
are not required to develop. If the provider partially completed the section, MACs shall obtain the 
missing information elsewhere on the CMS-855 application, in the supporting documentation, if 
available, or using the DEA sources available to them; otherwise, the MAC is required to develop. 
 
DEA certificates need not be submitted if the applicable DEA information was furnished on 
the Form CMS-855O application. Similarly, if the aforementioned certificates are furnished 
but the applicable CMS-855 sections are blank, no further development is needed by the MAC. 
 
 
Section 3:  Final Adverse Legal Action 
 
This section captures information on final adverse legal actions, such as convictions, exclusions, 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11  revocations, and suspensions. The provider shall refer to the instructions in Section 3 for the 
types of final adverse legal actions that must be reported. All applicable final adverse actions 
must be reported in this section regardless of whether any records were expunged or any appeals 
are pending. If a final adverse legal action is disclosed in this section, the provider must furnish 
documentation concerning the type and date of the action, what court(s) and law enforcement 
authorities were involved, and how the adverse action was resolved. The documentation must be 
furnished regardless of whether the adverse action occurred in a state different from that in 
which the provider seeks enrollment or is enrolled.  With the exception of any federal/state 
felony convictions within the preceding 10 years, identified in Section 3A1, all final adverse 
actions must be reported regardless of when they occurred. 
 
If the final adverse legal action is not reported but uncovered during the screening of the 
application, the MAC shall follow previous established guidance to address the missing 
information. 
Section 4: Medical Specialty Information 
This section captures the physician, eligible professional or other non-physician type specialty of 
the provider. Please refer to the General Information section for a list of the providers who are 
eligible to order and certify items and services to Medicare beneficiaries. 
A  Physician Specialty 
The provider shall select their primary specialty in this section. Only one specialty shall be 
selected. The provider must meet all state requirements for the type of specialty checked. If a 
physician specialty is not identified, the MAC shall send a development request to the 
provider/contact person to obtain the missing data. 
B  Eligible Professional or Other Non-Physician Type Specialty 
 
The provider shall select their Eligible Professional or Other Non-Physician Type Specialty in 
this section. Only one specialty shall be selected. Eligible Professional or Other Non-Physician 
Type Specialty must meet specific licensing, certification, educational and work experience 
requirements for the type of specialty selected. If a Eligible Professional or Other Non-
Physician Type Specialty is not identified, the MAC shall send a development request to the 
provider/contact person to obtain the missing data. 
 
Section 5:  Important Address Information 
 
The correspondence address must be one where the MAC can directly contact the applicant to 
resolve any issues once the provider is enrolled in the Medicare program. It cannot be the 
address of a billing agency, management services organization, chain home office, or the 
providers representative (e.g., attorney, financial advisor). It can, however, be a P.O. Box or, in 
the case of an individual practitioner, the persons home address. The MAC may accept a 
particular correspondence address if it has no reason to suspect that it does not belong to or is not 
somehow associated with the provider. If a particular address lacks a city or state, the MAC can 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11  verify the missing data in any manner it chooses. In addition, the MAC can obtain the zip + four 
from either the U.S. Postal Service or address validation functionality in PECOS. 
 
The provider may list any telephone number it wishes as the correspondence phone number. The 
number need not link to the listed correspondence address. The MAC may accept this telephone 
number if it has no reason to suspect that it does not belong to or is not somehow associated with 
the provider. If the provider fails to list a correspondence telephone number and it is required for 
the application submission, the MAC shall develop for this information  preferably via email or 
fax. 
The provider may list an email address, however, email is not required. The email address listed 
on the application can be a generic email address. It need not be that of a specific individual. The 
MAC may accept a particular email address if it has no reason to suspect that it does not belong 
to or is not somehow associated with the provider. 
 
Section 6:  Contact Person Information 
 
This section captures information regarding the person who should be contacted regarding this 
application. Multiple contact persons are allowed to be captured and the provider/contact person 
may copy this page and include in the Form CMS-855O submission to the MAC. The MAC has 
the discretion to use the contact persons listed in section 6 of the Form CMS-855O for all written 
and oral communications (e.g., mail, email, telephone) related to the providers Medicare 
enrollment. Such communication need not be restricted to a particular enrollment application of 
the provider that the MAC is currently processing. Nor is the MAC required (again, unless either 
CMS or the provider directs otherwise) to send certain materials to the correspondence mailing 
or email address rather than the contact persons mailing or email address. MACs shall validate 
that the: 
  Contact person provided his/her first name, middle initial, and last name with any 
suffixes as well as the address, city/town, state, zip code, telephone and fax number 
(optional). 
  Contact person supplied an email address, although this is not required. 
  Contact Person listed his or her relationship or affiliation to the individual practitioner or 
clinic/group/organization, although this is not required. 
  Communications regarding the processing of the Form CMS-855O shall be sent to the 
contact person listed. If multiple contact persons are listed, the MAC shall contact the 
first contact person listed on the application. If they are not available, the MAC shall 
contact the other person(s) listed, unless the provider indicates otherwise via any means. 
  If no contact person is listed in this section, the MAC shall contact the provider in 
Section 2 or another contact person on file. The MAC need not develop for the 
information in this section. 
  If a contact person is listed, any other missing data (e.g., address, e-mail) can be captured 
via telephone.  This instruction applies only to Section 5. 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11   
If this section is completely blank, the MAC need not develop for this information and can 
simply contact the physician or practitioner. 
 
Section 7: Penalties for Falsifying Information on this Application 
 
This section explains the penalties for deliberately furnishing false information in this application 
to gain or maintain enrollment in the Medicare program. 
 
Section 8: Certification Statement and Signature 
 
The provider is the only person who can sign this application. The authority to sign the 
application on behalf of the provider may not be delegated to any other person. The certification 
statement contains certain standards that must be met for initial and continuous enrollment in the 
Medicare program solely to order and certify items and services for Medicare beneficiaries. 
Note: Exceptions to the above policy may apply in the case of death, an executor of the estate, 
may sign on behalf of the deceased provider. 
 
All signatures must be original and signed in ink (blue ink preferred). Applications with 
signatures deemed not original will not be processed. Stamped, faxed or copied signatures will 
not be accepted. 
A signed certification statement shall accompany the paper Form CMS-855O. If the provider 
submits an invalid certification statement or fails to submit a certification statement, the MAC 
shall still proceed with processing the application. An appropriate certification statement shall be 
solicited as part of the development process. This includes certification statements that are: (a) 
unsigned; (b) undated; (c) contains a copied or stamped signature; (d) was signed (as reflected 
by the date of signature) more than 120 days prior to the date on which the MAC received the 
application); (e) for paper Form CMS-855O submissions, someone other than the physician or 
non-physician practitioner signed the form, except as noted above; or (f) missing certification 
statements. The MAC shall send one development request to include a list of all of the missing 
required data/documentation, including the certification statement. The MAC may reject the 
providers application if the provider fails to furnish the missing information on the enrollment 
application - including all necessary documentation - within 30 calendar days from the date the 
MAC requested the missing information or documentation. Unless otherwise stated: 
 
  The certification statement may be returned via scanned email, fax or mail to the MAC 
(as long as an original certification statement signature exist on file). 
 
  The MAC is not required to compare the signature thereon with the same providers 
signature on file to ensure that it is the same person. The MAC shall not request the 
submission of a drivers license or passport to verify a signature. 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11   
Note:  Web-based application must be accompanied by an e-signature or web certification in 
order for the MAC to begin processing the application. 
 
Instructions for CMS-855O Medicare Enrollment Application  Enrollment for Eligible Ordering, Certifying 
and Prescribing Physicians, and Other Eligible Professionals 
Page 11