Department of Health and Human Services 
OFFICE OF 
INSPECTOR GENERAL 
Accuracy of Unique Physician 
Identification Number Data 
JUNE GIBBS BROWN 
Inspector General 
OCTOBER 1999 
OEI-07-98-00410  OFFICE OF INSPECTOR GENERAL 
The mission of the Office of Inspector General (OIG), as mandated by Public Law 95-452, as 
amended by Public Law 100-504, is to protect the integrity of the Department of Health and 
Human Services programs as well as the health and welfare of beneficiaries served by them.  This 
statutory mission is carried out through a nationwide program of audits, investigations, 
inspections, sanctions, and fraud alerts.  The Inspector General informs the Secretary of program 
and management problems and recommends legislative, regulatory, and operational approaches to 
correct them. 
Office of Evaluation and Inspections 
The Office of Evaluation and Inspections (OEI) is one of several components of the Office of 
Inspector General.  It conducts short-term management and program evaluations (called 
inspections) that focus on issues of concern to the Department, the Congress, and the public.  The 
inspection reports provide findings and recommendations on the efficiency, vulnerability, and 
effectiveness of departmental programs. 
OEI's Kansas City office prepared this report under the direction of James H. Wolf, Regional 
Inspector General.  Principal OEI staff included: 
REGION  HEADQUARTERS 
Perry A. Seaton, Project Leader  Bambi Straw, Program Specialist

Tricia Fields, Program Analyst  Barbara Tedesco, Mathematical Statistician

Mike Craig, Program Inspection Assistant  Brian Ritchie, Program Analyst

Scott Horning, Program Analyst 
To obtain copies of this report, please call the Kansas City Regional Office at (816) 426-3697. 
Reports are also available on the World Wide Web at our home page address: 
http://www.dhhs.gov/progorg/oei  E X E C U T I V E   S U M M A R Y  
PURPOSE 
To determine whether the information associated with Unique Physician Identification 
Numbers is complete and accurate. 
BACKGROUND 
The Consolidated Omnibus Budget Reconciliation Act of 1985 requires physicians and 
other health care professionals to obtain a Unique Physician Identification Number 
(UPIN).  This is a national number that distinguishes the individual ordering or furnishing 
the service or supply from the entity requesting or receiving Medicare reimbursement, 
such as corporations, clinics and partnerships.  In 1989, the Health Care Financing 
Administration (HCFA) established the UPIN Registry and assigned unique numbers to 
Medicare physicians.  In 1994, the Registry was expanded to include non-physician 
practitioners and group practices.  The Registry also maintains data on each practice 
location, by Provider Identification Number (PIN).  The UPIN remains active as long as 
there is at least one active PIN.  The HCFA plans to use the Registry information as 
source data for the National Provider Identifier, which will replace UPINs and PINs after 
the year 2000. 
Before the unique identifier is assigned, the individual or entity must enroll with the 
Medicare carrier and provide documentation of any professional and governmental license 
requirements.  Each claim for Medicare reimbursement must list the UPIN for the service 
provider, the number of the referring professional, if any, and the entitys PIN for the 
practice location. 
We obtained the most recent UPIN Registry, also known as the Medicare Physician 
Identification and Eligibility Record data base (October 1998).  We analyzed it to 
determine if data was missing or contained improbable entries.  In addition, we validated 
information for a stratified sample of providers with State license agencies, independent 
certification entities, and Medicare carriers to determine the error rate for the sample. 
FINDINGS 
HCFA Has Taken Meaningful Actions to Enhance the Accuracy of UPIN Data 
The HCFA has implemented a number of significant enhancements to the provider 
enrollment process to improve program safeguards and increase the reliability of UPIN 
data.  These changes include: additional controls on the assignment of provider numbers; 
new requirements to conduct extensive verification and authentication of license and 
professional qualifications of number applicants; shortened protocols to deactivate 
numbers that do not have recent utilization; requirements for the provider to notify the 
carrier of any changes in their status; and mandatory inclusion of the Social Security 
Number.  In addition, HCFA plans to require the periodic re-validation of provider 
information. 
1 
Accuracy of UPIN Data  OEI-07-98-00410  As a result of HCFA actions, our analysis of the sample and the universe shows that 
virtually all Registry data fields are complete and contain feasible entries.  We identified 
only 92 Social Security Numbers associated with more than one UPIN, a significant 
improvement when compared to the 1995 Health Economics Research study which found 
up to 11,600 providers with potentially multiple UPIN registrations. 
The Social Security Number, an important identifier, was inaccurate for 13 percent of 
UPINs.  We recognize, however, the Balanced Budget Act of 1997 has only recently 
required providers to furnish this information to receive Medicare payment. 
Despite These Efforts, Problems Continue to Exist With Some Physician Registry 
Data 
Almost one-fourth of the active UPINs have no recent Medicare claims activity 
From our sample we estimate 23 percent of the active UPINs had no claims activity for 
the past year and 17 percent had no claims activity for the past 3 years.  We also estimate 
39 percent of the associated active Provider Identification Numbers for individual practice 
settings have no Medicare claims activity within the past year.  Twenty-seven percent have 
no activity for the past 3 years. 
Coding instructions and formats adversely affect the usefulness of information 
<	 We estimate 88 percent of the entries for the State license number do not agree with 
the licensure agencies information.  Of these errors, 72 percent of the numbers differ 
in format and 28 percent contain leading zeros in the first 3 positions of the number. 
Our analysis of the universe established that over 46 percent of the numbers also 
contain 3 or more leading zeros.  This convention can create difficulties in performing 
computer matching and number verification. 
<	 We estimate inaccurate professional school codes for 8 percent of the UPINs and for 
5 percent of the PINs. 
<	 We noted additional problems with the coding for physician specialities and 
certifications.  For the universe, the board certification code, which is optional data, 
contained feasible codes for only 62 percent of the records for the primary speciality 
and 30 percent of the records for the secondary speciality. 
Some providers have numerous active PINs 
Many providers (68 percent of the total UPIN universe) had 3 or less PINs and most 
(97.9 percent) had 10 or fewer.  However, the remaining UPINs had from 11 to 
57 separate billing numbers for each UPIN for a total of 9,535 PINs.  This small group of 
providers, in reflecting a high volume of billing numbers, represent an enhanced risk for 
improper billing or utilization by the provider, employees, a third party, or even carrier 
personnel. 
2 
Accuracy of UPIN Data  OEI-07-98-00410  Some UPIN Data is Inconsistent 
Several UPIN data fields for a providers individual practice settings contain data that 
apply to all of their practice locations.  Examples include: State license number; 
Professional School Code; and Primary and Secondary Speciality Codes.  We found 
carriers are updating only some of the provider-specific practice information on the UPIN 
record, resulting in inconsistencies for different practice locations.  Maintaining such 
information on each providers practice setting greatly increases the opportunity for 
errors, omissions, and discrepancies. 
RECOMMENDATIONS 
We have found a number of UPIN and PIN issues that need attention.  However, many of 
them can be effectively addressed when HCFA implements its process for periodic 
re-validation of provider information. 
Deactivate UPINs and PINs for Inactive Providers and Practice Locations 
The HCFA should ensure that carriers deactivate provider numbers and UPINs in

accordance with its instructions when no claims have been submitted to them for the

preceding 12 months.  This should be an active review element of the periodic Carrier

Performance Evaluation review.  To reduce program vulnerabilities and minimize

administrative costs, HCFA could consider implementing a shorter time frame 

(i.e., 2 consecutive quarters).

Improve Data Entry Instructions for Specific Data Fields 
We recommend the Medicare Carriers Manual Part 4,  1015, Exhibit 2, be revised to 
specify that the State license number be entered exactly as shown on State records and 
licenses.  The instructions should specify that the number be left justified, and that 
characters, numbers, and spaces are acceptable.  In addition, HCFA should review 
instructions for coding provider specialities and certifications to provide for the 
possibilities of none under provider speciality and not applicable under board 
certification.  This should significantly reduce coding errors by carrier personnel for health 
providers who are not board certified or for professions that are not independently 
certified. 
Establish a Priority to Review Individuals with Numerous PINs 
The HCFA should require carriers to establish a priority for review of individuals with 
numerous (i.e., more than 10) PIN numbers.  Such reviews should address the utilization 
of these numbers and their legitimacy. 
Reconcile Identical Fields in UPIN and PIN Records Before Implementing National 
Provider Identifier 
The HCFA should ensure that its contractors update applicable changes to all related 
UPIN and PIN records.  In planning for the National Provider Identifier and National 
Provider System, HCFA could avoid inconsistent data between these records by using a 
3 
Accuracy of UPIN Data  OEI-07-98-00410  single file for practitioner-specific data, or linking identical fields in different records to 
flag conflicting entries. 
AGENCY COMMENTS 
The HCFA concurs with the report and has undertaken or is planning meaningful steps to 
implement the recommendations.  Appendix D contains the complete text of these 
comments. 
4 
Accuracy of UPIN Data  OEI-07-98-00410  T A B L E   O F   C O N T E N T S  
PAGE 
EXECUTIVE SUMMARY

INTRODUCTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6

FINDINGS

HCFA has taken actions to enhance UPIN data accuracy . . . . . . . . . . . . . . . . . . . . . . . 10

Problems Continue to Exist With Some Physician Registry Data  . . . . . . . . . . . . . . . . .  10

<  No recent claims for almost one-fourth of active UPINs  . . . . . . . . . . . . . . . . . . . . 10

<  Coding instructions adversely affect the usefulness of information . . . . . . . . . . . . .  11

<  Some providers have numerous active PINs  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

<  Some UPIN Data is Inconsistent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

RECOMMENDATIONS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13

ENDNOTES  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15

APPENDICES

A: Estimates and Confidence Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

B: Analysis of the Universe - UPIN Header Record Data . . . . . . . . . . . . . . . . . . . . . . . 17

C: Analysis of the Universe - UPIN Practice Setting (PIN) Data . . . . . . . . . . . . . . . . . .  20

D: Agency Comments  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

5 
Accuracy of UPIN Data  OEI-07-98-00410  I N T R O D U C T I O N  
PURPOSE 
To determine whether the information associated with Unique Physician Identification 
Numbers is complete and accurate. 
BACKGROUND 
The Consolidated Omnibus Budget Reconciliation Act of 1985, 9201(g)1 requires 
physicians and other health care professionals to obtain a Unique Physician Identification 
Number (UPIN).  In 1989, the Health Care Financing Administration (HCFA) established 
the UPIN Registry, formerly known as the Physician Registry and assigned unique 
numbers to Medicare physicians.  In 1994, the UPIN Registry was expanded to include 
non-physician practitioners and medical group practices. 
The UPIN is used nationally to uniquely identify physicians, non-physician practitioners 
and medical group practices.  These individuals or entities often furnish or bill for medical 
services from several locations or states which are in different carrier jurisdictions.  This 
national number distinguishes the individual ordering, referring, or furnishing the service 
or supply from the entity requesting or receiving Medicare reimbursement for the service, 
such as corporations, clinics and partnerships. 
Roles of the Carriers 
Before a unique identifier is assigned, the individual or entity must complete an application 
for enrollment with the carrier and provide documentation of professional and 
governmental license requirements.  The HCFA has standardized provider enrollment and 
update forms for all carriers, implementing the current version August 1, 1998.  As part of 
enrollment, carriers validate that the entity or individual requesting the number meets 
license and other standards under Federal and State laws.2 
Upon completion of all mandated validation requirements, carriers initiate a computer 
inquiry to the Registry to request issuance of the UPIN for the applicant.  The carrier 
assigns a Provider Identification Number (PIN) for each practice setting.  While a 
physician or other health care practitioner may have more than one PIN (i.e., the provider 
has more than one billing location), only one UPIN is to be issued.  The Registry maintains 
data on each PIN under the providers UPIN. 
Once the Registry assigns a UPIN and establishes a record, the carrier is responsible for 
assuring that the information on both their provider file and the Registry is updated when 
changes, additions, or deletions are needed.  The carrier performs this process 
electronically or by mail.  In addition, when the Registry receives information which 
creates a question about the status of the provider, such as suspected death, sanction, or 
fraud, it generates an electronic investigational alert by UPIN to the carrier for their 
research and investigation. 
6 
Accuracy of UPIN Data  OEI-07-98-00410  The billing entity must list the service providers UPIN, the referring professionals 
number (if any), and the entitys PIN on the claim to receive Medicare reimbursement. 
However, carriers can initially process claims submitted by a new provider without a 
unique number through use of a temporary generic number, only until a permanent number 
is issued. 
As a program safeguard, carriers are instructed to deactivate the PIN if it remains inactive 
(no claims activity) for 12 consecutive months.  Prior to October 1998, the Medicare 
Carriers Manual required deactivation of numbers after 3 years of no claims activity.  The 
UPIN remains active as long as there is at least one active PIN for the provider.  If there is 
no activity on any PIN for 12 months, the UPIN should also be deactivated.  In order to 
reactivate a PIN or UPIN, the provider must complete a new General Enrollment form 
and the carrier must verify all enrollment information. 
Role of the Registry Contractor 
Transamerica Occidental Life Insurance Company establishes and maintains the Registry 
of physicians, health care practitioners, and group practices receiving Medicare Part B 
payments.  During a 5 month implementation period from January - May 1989, the 
Registry processed 1.2 million records submitted by 57 Medicare carriers.3 
The Registry contractor maintains the UPIN Registry, also known as the Medicare 
Physician Identification and Eligibility Record (MPIER), a data base of physician and 
other health provider enrollment information.  When a carrier electronically requests 
assignment of a  UPIN, the Registry staff performs its own validation to determine if the 
enrollment request can be added to the Registrys data file. 
If the Registrys internal validation checks identify discrepancies which need further 
review, it generates electronic exception messages to the carrier.  The carrier is to conduct 
the needed validations and either transmit the corrections or contact the Registry to 
resolve the problem.  When all validation is completed and approved, the Registry 
transmits the UPIN to the carrier. 
Provider Number Issues Previously Identified by the OIG and HCFA 
The OIG completed three studies that examined problems applicable to Medicare provider 
numbers.  These studies identified problems with 
<  the accuracy and completeness of carrier provider files. 
<  inadequate carrier controls to deactivate provider numbers for individuals who are not 
submitting claims or have lost the legal authority to practice. 
<  poor communications with State licensing authorities.4 
7 
Accuracy of UPIN Data  OEI-07-98-00410  As a result, the HCFA contracted with Health Economics Research, Inc. to evaluate the 
quality of the Registry data.5  Its review identified the following problems: 
<  as many as 11,600 providers may potentially have more than one number; 
<  nearly 14 percent of the practice settings are no longer being used by the physicians; 
<  the data base contains missing, erroneous, or infeasible entries for several data 
elements (i.e., State license number, date of birth, school code and graduation year); 
and 
<  Railroad Retirement Board carriers account for a disproportionately large share of the 
problems identified. 
Implementation Plan for the National Standard Health Care Provider Identifier 
In July 1993, HCFA undertook an initiative to establish a standardized provider identifier, 
the National Provider Identifier (NPI), that will replace the UPINs and PINs.  This 
identifier is to be an eight-position alpha numeric identifier.  It will be used by all health 
entities that bill or initiate referrals for Medicare patients and ultimately will be used by all 
health care providers and insurers.  As part of this process, HCFA is concurrently 
developing a National Provider System which will replace the data currently in the MPIER 
data file.  The HCFA estimates that the National Provider Identifier will not be operational 
until the year 2000. 
Periodic Re-Validation of Providers 
The HCFA is preparing a Notice of Proposed Rule for public comment which will for the 
first time require Medicare carriers to periodically re-validate information for its providers. 
The proposed rule will require physicians and other health providers to update their 
information every 3 years.  New providers will be validated annually for the first 
3 years and then will go to a 3 year re-validation cycle.  However, HCFA currently has no 
plans to validate all provider information prior to implementation of the National Provider 
Identifier data base. 
METHODOLOGY 
We conducted an analysis of the Medicare Physician Identification and Eligibility Record 
(MPIER) data base as of October 1998 to measure data integrity and its validity for the 
universe and a random sample of UPINs.  Further, we performed data comparisons to 
identify providers who may have more than one UPIN.  The estimates are weighted in 
accordance with the sample design.  Percentages are reported at the 95 percent confidence 
interval.  The confidence intervals for these percentages are detailed in Appendix A. 
We also selected a random sample of 225 UPINs associated with 424 PINs from the 
MPIER file, stratified by the year of the last record update to permit analysis of data 
quality and reliability over time.  The sample design is given in the table on the following 
page. 
8 
Accuracy of UPIN Data  OEI-07-98-00410  SAMPLE DESIGN

Year UPIN  Sample  Universe  Universe 
Strata  Last Updated  Size  Size  Percent 
Strata 1  1989 - 1994  75  54,284  6.6% 
Strata 2  1995 - 1996  75  284,109  34.6% 
Strata 3  1997 - 1998  75  482,110  58.8% 
Strata Total:  225  820,503  100.0% 
Data Integrity 
The records in the MPIER file were sorted by UPIN, the date the record was created, and 
the date that the record was last updated.  We performed frequency counts and analysis of 
other data fields to determine the number and percentage of data that was missing or 
contained improbable entries.  We also performed analysis of variable entries to determine 
if the data appeared to be accurate and complete when compared to other information 
contained in the providers identification eligibility record.  Further, we determined if the 
missing or questionable data was predominately from only certain data elements and 
issuing carriers. 
Data Validity 
To verify the sanction status of the sampled providers, we searched both the OIG

Exclusions List and the General Services Administrations List of Parties Excluded from

Federal Procurement and Non-Procurement Programs.  We also validated education,

professional license, and speciality through use of the Internet sites of State Professional

Boards and professional entities such as the American Medical Association and the

American Board of Medical Specialities.  Where Internet information was unavailable or

incomplete, we contacted the applicable State professional board.  In addition, we

contacted Medicare carriers to validate the sampled active UPINs and PINs, and to

identify providers who had not submitted claims within the previous 12 or 

36 consecutive months.

Multiple Numbers 
We matched the universe of UPINs to the associated Social Security Number on the 
Registry to identify providers who may have more than one UPIN.  We also compared the 
providers name, date of birth and school information. 
We conducted this inspection in accordance with the Quality Standards for Inspections 
issued by the Presidents Council on Integrity and Efficiency. 
9 
Accuracy of UPIN Data  OEI-07-98-00410  F I N D I N G S  
HCFA Has Taken Meaningful Actions to Enhance the 
Accuracy of UPIN Data 
The HCFA has implemented a number of significant enhancements to the provider 
enrollment process designed to improve program safeguards and increase the reliability of 
provider enrollment data.  These changes include: additional controls on the assignment of 
provider numbers; new requirements to conduct extensive verification and authentication 
of license and professional qualifications of number applicants; shortened protocols to 
deactivate numbers after 12 months of claims inactivity; requirements for the provider to 
notify the carrier of any changes in their status which are updated by the carrier to the 
Registry, and mandatory inclusion of the Social Security Number.  In addition, HCFA is 
proceeding with plans to require the periodic re-validation of provider information. 
As a result of HCFA actions, our analysis of the sample and the universe shows that 
virtually all Registry data fields are complete and contain feasible entries (Appendices B 
and C).  We identified only 92 Social Security Numbers associated with more than one 
UPIN.  This is a significant improvement when compared to the 1995 Health Economics 
Research study of UPIN Registry data which found that up to 11,600 providers may have 
multiple UPIN registrations. 
The Social Security Number, an important identifier, was inaccurate for 13 percent of the 
total UPINs.  We recognize, however, the Balanced Budget Act of 1997 (Public Law 105-
32) has only recently required providers to furnish this information to receive Medicare 
payment. 
Despite These Efforts, Problems Continue to Exist With 
Some Physician Registry Data 
Almost One-fourth of the Active UPINs Have No Recent Medicare Claims Activity 
In order to deactivate a UPIN, all of the associated PINs must be inactive.  To confirm 
this, we compared the active UPINs to their claims activity for all practice settings.  From 
our sample we estimate 23 percent of the active UPINs had no claims activity for the past 
year and 17 percent had no claims activity for the past 3 years.  We also found that 
four of the active numbers in the sample belonged to providers who were deceased prior 
to 1996.  While the carriers had deactivated the PINs, the corresponding UPINs remained 
active. 
A provider should have only one UPIN but can have several PINs, which are billing 
numbers assigned by Medicare contractors to designate separate practice locations or 
10 
Accuracy of UPIN Data  OEI-07-98-00410  accounting designations.  Based on sample data, we estimate 39 percent of the associated 
active PINs have no Medicare claims activity within the past year.  Twenty-seven percent 
have no activity for the past 3 years. 
Active UPINs and PINs with no recent claims activity represent a vulnerability to the 
Medicare program as unscrupulous individuals and organizations could use these numbers 
to submit fraudulent claims and supporting documents.  Also, maintaining these numbers 
creates an unnecessary administrative cost for HCFA and its Medicare contractors. 
Performing provider mailings, researching undeliverable mail, maintaining provider files, 
and paying for computer time and storage are a few of the ongoing operational expenses 
that can be reduced by deactivating these unused numbers. 
The HCFA has notified Medicare carriers to deactivate practice settings PINs that have 
not had claims activity for 1 year and to update the UPIN Registry database either 
electronically or by mailed notification.  Previously, carriers deactivated these settings 
after 3 years of claims inactivity. 
Coding Instructions and Formats Adversely Affect the Usefulness of Information 
From our sample we estimate 88 percent of entries for the State license number do not 
agree with licensure agencies information.  Of these errors, 72 percent of the numbers 
differ in format, such as missing alpha characters, digits, dashes or spaces and 28 percent 
contain leading zeros in the first 3 positions which do not match the number on file with 
the State licensing entity.  Our analysis of the universe also established that 46 percent of 
the numbers contain 3 or more leading zeros (Appendix C).  This convention can create 
difficulties in performing computer matching and verification. 
The HCFA instructed Medicare carriers to enter the State license number in this 
12-position data field right justified and preceded with zeros.6  These instructions can alter 
the appearance of the number and therefore, greatly limit the usefulness of this information 
for automated data matching and verification. 
We estimate inaccurate professional school codes for 8 percent of the UPINs and 
5 percent of the PINs.  Carriers currently use specific school coding for Medical Doctors, 
Doctors of Osteopathy, Chiropractors, and Optometrists for U.S. educated professionals. 
Categorical coding is used for all others, including professionals educated abroad.7 
We found additional problems with the sample data for physician primary board speciality 
and certification.  The HCFA instructions for these data fields do not specify coding for 
those health professionals not certified by independent boards.5  Moreover, the coding 
options do not provide a choice of none or non-applicable.  From our sample we 
estimate the primary provider speciality code, a required entry for the UPIN Registry, was 
83 percent accurate.  However, the primary speciality board certification code, which is 
optional, was only 28 percent accurate.  Problems detected included extensive use of the 
U (unknown) code and inconsistent coding for health professionals such as 
chiropractors, optometrists, nurses (excluding certified registered nurse anesthetists), 
psychologists, and physical therapists who are not certified by independent boards. 
11 
Accuracy of UPIN Data  OEI-07-98-00410  For the universe, since we could not determine the accuracy of the primary provider 
speciality code, we analyzed the data to determine if it contained feasible values as defined 
by HCFA.  We found 99.9 percent of the entries corresponded to legitimate speciality 
codes.  However, the primary speciality board certification was coded as unknown for 
38 percent of the practices (Appendix C). 
We identified the same issues in the sample for the physician secondary board speciality 
and certification (optional data), but the problems were more pronounced.  We estimate 
only 76 percent of the speciality codes and 4 percent of the secondary speciality board 
certification codes were accurate.  Problems detected included inconsistent coding for 
board certification and use of all code choices, or no entry for the speciality Carrier 
Wide, which is synonymous for none or not applicable.  This accounted for 92 percent of 
the errors in the secondary speciality board certification code.  For the universe, the 
secondary provider speciality code was blank 94 percent of the time, and the 
corresponding secondary speciality board certification code contained an entry of 
unknown (70 percent) or did not contain data (25 percent).  Refer to Appendix C. 
Some Providers Have Numerous Active PINS 
In analyzing the number of active practices for each UPIN, we found that many providers 
(68 percent of the total UPIN universe) had 3 or less practice settings and most 
(97.9 percent) had 10 or fewer settings.  However, the 9,535 remaining PIN numbers had 
up to 57 separate billing numbers or practice settings for each UPIN: 
<  8,219 providers had 11 to 20; 
<  820 providers had 21 to 30; 
<  414 providers had 31 to 40; 
<  78 providers had 41 to 50; and 
<  4 providers had 51 to 57 practice settings. 
This small group of providers, in reflecting a high volume of practice locations, represent 
an enhanced risk for improper billing or utilization by the provider, employees, a third 
party, or even carrier personnel. 
Some UPIN Data is Inconsistent 
Several UPIN data fields for a providers individual practice settings contain data that 
apply to all of their practice locations.  Examples include: State license number; 
Professional School Code; Primary and Secondary Speciality Codes; and Primary and 
Secondary Speciality Board Certification Codes.  We found carriers are updating only 
some of the provider-specific practice information on the UPIN record, resulting in 
inconsistencies for different practice locations.  Maintaining such information on each 
providers practice setting greatly increases the opportunity for errors, omissions, and 
discrepancies. 
12 
Accuracy of UPIN Data  OEI-07-98-00410  R E C O M M E N D A T I O N S  
Accurate enrollment and practice information for Medicare providers is vital to ensure that 
only qualified health care professionals furnish treatment to Medicare beneficiaries.  The 
HCFA has stated its intent to use the data contained in the UPIN Registry as source 
information for the NPI data base.  Therefore, it is important that the UPIN and PIN data 
be both accurate and specific.  While HCFA has initiated important improvements in the 
enrollment and updating of health care providers which should greatly improve the 
accuracy and reliability of the data records, a number of problems continue to exist. 
Accordingly, we recommend that HCFA implement the following actions to improve the 
overall accuracy and reliability of this data. 
Deactivate UPINs and PINs for Inactive Providers and 
Practice Locations 
The HCFA should ensure that carriers deactivate PINs and UPINs in accordance with its 
instructions when no claims have been submitted to them for the preceding 12 months. 
This should be an active review element of the periodic Carrier Performance Evaluation 
(CPE) review.  To reduce program vulnerabilities and minimize administrative costs, 
HCFA could consider implementing a shorter time frame (i.e., 2 consecutive quarters). 
Improve Data Entry Instructions for Specific Data Fields 
We recommend the Medicare Carriers Manual Part 4,  1015, Exhibit 2, be revised to 
specify that the State license number be entered exactly as shown on State records or 
licenses.  The instructions should specify that the number be left justified, and that 
characters, numbers, and spaces are acceptable. 
In addition, HCFA should revise instructions for coding provider specialities and 
certifications, to provide for the possibilities of none under provider speciality and not 
applicable under board certification.  This should significantly reduce coding errors by 
carrier personnel for health providers who are not board certified or for professions that 
are not independently certified. 
Establish a Priority to Review Individuals with Numerous 
PINs 
As part of its re-validation of providers, HCFA should require carriers to establish a 
priority for the review of individuals with numerous (i.e., more than 10) PIN numbers. 
Such reviews should address the utilization of these numbers and their legitimacy. 
13 
Accuracy of UPIN Data  OEI-07-98-00410  Reconcile Identical Fields in UPIN and PIN Records Before 
Implementing NPI 
The HCFA should ensure that its contractors update applicable changes to all related 
UPIN and PIN records.  In planning for the National Provider Identifier and National 
Provider System, HCFA could avoid inconsistent data between these records by using a 
single file for practitioner-specific data, or linking identical fields in different records to 
flag conflicting entries. 
AGENCY COMMENTS 
The HCFA concurs with the report and has undertaken or is planning meaningful steps to 
implement the recommendations.  Appendix D contains the complete text of these 
comments. 
14 
Accuracy of UPIN Data  OEI-07-98-00410  E N D N O T E S  
1.  Public Law (P.L. 99-272), signed into law April 7, 1986. 
2.  Medicare Carriers Manual, Professional Relations, (Pub. 14-4)  1030.5D.  As part of the 
enrollment process, carriers must: 
<  establish that the facility, entity, or individual is properly licensed, certified, and 
registered under State law; 
<	 establish evidence of qualifying course work from educational institution(s) from 
which the applicant received his medical, professional, or related training including 
Diplomas or degrees; 
<  authenticate each board certification listed by the applicant; 
<  establish that the facility, entity, or individual is not excluded from the Medicare and 
Medicaid programs; 
<	 verify that the applicant is not on the General Services Administrations List of 
Parties Excluded from Federal Procurement and Non-procurement Programs (List of 
Parties); and, 
<	 determine whether the individual or entity has or previously had a Medicare Provider 
Identification Number (PIN). 
3.  Health Economics Research Inc., Unique Physician Identification Number (UPIN) Validation 
Studies: Carrier Analysis, August 23, 1994, p 21. 
4.  Previous Office of Inspector General Reports include 
Carrier Maintenance of Medicare Provider Numbers, OEI-06-89-00870, June 1991. 
Carrier Assignment of Medicare Provider Numbers, OEI-06-89-00871, April 1992. 
Carriers Still Need to Purge Unused Provider Numbers, OEI-01-94-00231, 
December 1995. 
5.  Health Economics Research, Inc. issued the following Unique Physician Identification 
Number (UPIN) Validation Studies 
Carrier Edits, May 27, 1994. 
Carrier Analysis, August 23, 1994. 
Documentation for the UPIN Integrity and Multiple-UPIN Files, October 5, 1994. 
Final Report, February 7, 1995. 
Understanding Properties of the UPIN for Claims-Based Research, February 11, 1997. 
6.  Medicare Carriers Manual, Professional Relations, (Pub. 14 - 4) 1015, Exhibit 2. 
7.  Ibid, Exhibits 3A - 3D.  Specific school code listing  for M.D.s, D.O.s, D.P.M.s, D.C.s and 
O.D.s. 	 The following categorical codes are used for other health professionals: 
10000 - D.D.M.s; 
20000 - D.D.S.s 
60000 - Nurses; 
70000 - other U.S. educated health professionals; and 
99999 - professionals educated abroad. 
15 
Accuracy of UPIN Data  OEI-07-98-00410  A P P E N D I X  A  
Estimates and Confidence Intervals

The following table summarizes the estimates at the 95 percent confidence intervals for key data 
presented in this report.  The estimates refer to projected error rates for specified variables in the 
Universe of the UPIN Registry. 
Weighted  95% 
Error  Confidence 
Data Variable  Percentage  Interval 
No Claims Filed in the Last 12 Months (UPIN)  23%  +/- 6.5% 
No Claims Filed in the Last 36 Months (UPIN)  17%  +/- 5.7% 
No Claims Filed in the Last 12 Months (PIN)  39%  +/- 6.7% 
No Claims Filed in the Last 36 Months (PIN)  27%  +/- 5.9% 
State License Number (UPIN - overall)  88%  +/- 5.2% 
State License Number (UPIN - format problem)1  72%  +/-7.1% 
State License Number (UPIN - leading zero problem)1  28%  +/- 7.1% 
Professional School Codes (UPIN)
 8%  +-/ 4% 
Professional School Codes (PIN)
 5%  +/- 2.8% 
Primary Board Speciality Code (UPIN)
 17%  +/-6.1% 
Primary Board Certification Code (UPIN)
 72%  +/-6.9% 
Secondary Board Speciality Code (UPIN)
 24%  +/-6.8% 
Secondary Board Certification Code (UPIN)
 96%  +/-3.2% 
1 These are the proportionate percentages that contribute to the overall estimated 88 percent 
error rate for the State License number. 
16 
Accuracy of UPIN Data  OEI-07-98-00410  A P P E N D I X  B  
Medicare Physician Identification

and Eligibility Record

Analysis of the Universe

UPIN Header Record Data

17 
Accuracy of UPIN Data  OEI-07-98-00410  Medicare Physician Identification and Eligibility Record Data Elements 
Analysis of the Universe - UPIN Header Record Data 
Percent of 
Field Identifier / Analytical Criteria  Total1  Universe 
Date of Birth 
Feasible Entry - Year code is 1918 to 1973, month and day are valid.2  677,996  98.6% 
Questionable Entry - Year code is 1901 to 1917, or 1899, month and day 
are valid.2  7,616  1.1% 
Erroneous Entry - Any code other than listed above.  1,171  0.2% 
Missing Entry -Year code is all 9's, 0's or blanks.  982  0.1% 
Date of Death 
Alive - Date code is 0's or blanks.  686,823  99.9% 
Feasible Entry - Year code is 1997 or 1998, month and day are valid.  476  0.1% 
Questionable Entry - Year code is 1901 to 1996, month and day are valid.  465  0.1% 
Erroneous Entry - Any code other than listed above.  1  * 
School Code 
Specific School Code Entry - Contains one of the school codes listed in 
the Medicare Carriers Manual.3  501,177  72.9% 
Foreign School Categorical Code - Entry is equal to code 99999.  121,294  17.6% 
Chiropractic School Categorical Code -Entry is equal to code 50000.  33,066  4.8% 
DDS Categorical School Code - Entry is equal to code 20000.  20,134  2.9% 
DDM Categorical School Code - Entry is equal to code 10000.  4,295  0.6% 
Erroneous Entry - Any code other than listed above.  3,812  0.6% 
Missing Entry - Code is all blanks, all 0's or 00001.  2,964  0.4% 
Retired School Code  947  0.1% 
Other Health Professions Categorical Code - Entry is equal to code 
70000.  68  * 
Nursing School Categorical Code - Entry is equal to code 60000.  8  * 
1 Universe total for each header record field is 687,765.
2 Span of years is comparable to interval used in the Health Economics Research Studies.
3 Medicare Carriers Manual, Professional Relations, (Pub 14-4)  1015, Exhibits 3A - 3D.
* Rounds to zero percent. 
18 
Accuracy of UPIN Data  OEI-07-98-00410  Medicare Physician Identification and Eligibility Record Data Elements 
Analysis of the Universe - UPIN Header Record Data 
Percent of 
Field Identifier / Analytical Criteria  Total1  Universe 
Graduation Year 
Feasible Entry - Year code is 1945 to 1998.4  670,994  97.6% 
Questionable Entry - Year code is 1935 to 1944.4  8,166  1.2% 
Erroneous Entry - Any code other than listed above.  5,858  0.9% 
Missing Entry - Year code is all 9's, 0's or blanks.  2,747  0.4% 
Sanction Code 
Not Sanctioned - Code is all blanks.  686,247  99.8% 
Feasible Entry - Code is A to R.5  1,459  0.2% 
Unknown - Individual is sanctioned but type of sanction action is code U 
for unknown.  57  * 
Erroneous Entry - Any code other than listed above.  2  * 
Sanction Date 
Not Sanctioned - Year code is all blanks or 0's.  685,573  99.7% 
Feasible Entry - Year code is 1966 to 1998, and month is valid.  2,059  0.3% 
Erroneous Entry - Any code other than listed above.  133  * 
Sanction Length 
Not Sanctioned - Code is all blanks or 0's.  685,616  99.7% 
Feasible Entry - Code for years of sanction is between 1 to 15, 20, 25, 30, 
35, 40, 45, 50, 99.  2,101  0.3% 
Questionable Entry - Code for years of sanction is 16 to 19, 21 to 24, 26 
to 29, 31 to 34, 36 to 39, 41 to 44, 46 to 49, 51 to 98.  48  * 
Social Security Number 
Feasible Entry  594,318  86.7% 
Missing Entry  1  * 
Zero Entry - Code is all 0's or 9's  93,446  13.3% 
4 Span of years is comparable to interval used in the Health Economics Research Studies.
5 Medicare Carriers Manual, Professional Relations, (Pub. 14 - 4) 1015, Exhibit 4.
* Rounds to zero percent. 
19 
Accuracy of UPIN Data  OEI-07-98-00410  A P P E N D I X  C  
Medicare Physician Identification and 

Eligibility Record Data Elements

Analysis of the Universe

UPIN Practice Setting (PIN) Data

20 
Accuracy of UPIN Data  OEI-07-98-00410  Medicare Physician Identification and Eligibility Data Elements
Analysis of the Universe - UPIN Practice Setting (PIN) Data 
Universe  Universe 
Field Identifier / Flag Description  Total1   Percent 
Date of Birth 
Feasible Entry - Year code is 1918 to 1973, month and day are valid.2  1,806,547  98.9% 
Questionable Entry - Year code is 1901 to 1917, or 1899, month and day 
are valid.2  12,198  0.7% 
Missing Entry - Year code is all 9's, 0's or blanks.  4,891  0.3% 
Erroneous Entry - Any code other than listed above.  2,443  0.1% 
Date of Death 
Alive - Date code is 0's or blanks.  1,826,062  100.0% 
Feasible Entry - Year code is 1997 or 1998, month and day are valid.  11  * 
Questionable Entry - Year code is 1901 to 1996, month and day are valid.  6  * 
School Code 
Specific School Code Entry - Contains one of the school codes listed in 
the Medicare Carriers Manual.3  1,366,674  74.8% 
Foreign School Categorical Code - Entry is equal to code 99999.  367,231  20.1% 
Chiropractic School Categorical Code - Entry is equal to code 50000.  46,045  2.5% 
DDS Categorical School Code - Entry is equal to code 20000.  25,011  1.4% 
Erroneous Entry -Any code other than listed above.  7,555  0.4% 
Missing Entry - Code is all blanks, all 0's or 00001.  6,056  0.3% 
DDM Categorical School Code - Entry is equal to code 10000.  5,321  0.3% 
Retired School Code  2,088  0.1% 
Other Health Professions Categorical Code - Entry is equal to code 
70000.  88  * 
Nursing School Categorical Code - Entry is equal to code 60000.  10  * 
1 Universe total for each practice field is 1,826,079.
2 Span of years is comparable to interval used in the Health Economics Research Studies.
3 Medicare Carriers Manual, Professional Relations, (Pub 14-4)  1015, Exhibits 3A - 3D.
* Rounds to zero percent. 
21 
Accuracy of UPIN Data  OEI-07-98-00410  Medicare Physician Identification and Eligibility Data Elements
Analysis of the Universe - UPIN Practice Setting (PIN) Data 
Universe  Universe 
Field Identifier / Flag Description  Total1   Percent 
Graduation Year 
Feasible Entry - Year code is 1945 to 1998.4  1,798,111  98.5% 
Questionable Entry - Year code is 1935 to 1944.4  13,352  0.7% 
Missing Entry - Year code is all 9's, 0's or blanks.  8,261  0.5% 
Erroneous Entry -Any code other than listed above.  6,355  0.3% 
Physician Status Code (Type of Provider Listed in Carriers Manual) 
Feasible Entry - Code is 1, 2, or 3.5  1,825,975  100.0% 
Erroneous Entry - Any code other than listed above.  104  * 
Credential Code 
Feasible Entry - Code is MD, DO, CH DPM, DDS, DDM, OD, CSW, PT, 
CP, AA, NP, OT, CNA, PSY, PA, CNM., CNS, AU.6  1,825,976  100.0% 
Erroneous Entry - Any code other than listed above.  103  * 
State License Number 
Lead Zeros - Code for the first 3 digits of the license number are 0's.  837,736  45.9% 
Number Justification - Entry is not right justified.  764,008  41.8% 
Feasible Entry - It contains an alpha numeric entry not otherwise listed.  208,606  11.4% 
Missing Entry - Code is all blanks.  12,510  0.7% 
Zero Entry - Code is all 0's.  3,219  0.2% 
License State Code 
Feasible Entry - Code is a standard postal state abbreviation (including 
U.S. properties).  1,826,073  100.0% 
Erroneous Entry - Any code other than listed above.  6  * 
4 Span of years is comparable to interval used in the Health Economics Research Studies.
5 Medicare Carriers Manual, Professional Relations, (Pub 14-4)  1015, Exhibit 2, (2).
6 Medicare Carriers Manual, Professional Relations, (Pub 14-4)  1015, Exhibit 2, (21).
* Rounds to zero percent. 
22 
Accuracy of UPIN Data  OEI-07-98-00410  Medicare Physician Identification and Eligibility Data Elements
Analysis of the Universe - UPIN Practice Setting (PIN) Data 
Universe  Universe 
Field Identifier / Flag Description  Total1   Percent 
Primary Speciality Code 
Feasible Entry - Contains one of the valid speciality codes listed in the 
HCFA Data Users Reference Guide.7  1,824,864  99.9% 
Unknown Entry -Code is 99.  618  * 
Retired Entry - Code is retired - osteopathic speciality code.  321  * 
Revised Entry - Code is 49 (formerly for a miscellaneous speciality, 
redesignated as an Ambulatory Surgical Center).  260  * 
Erroneous Entry - Any code other than listed above.  16  * 
Primary Speciality Board Certification Code 
Feasible Entry - Code is Yor N.  1,132,899  62.0% 
Unknown Entry - Code is U.  693,180  38.0% 
Secondary Speciality Code 
Missing Entry - Code is all blanks.  1,712,541  93.8% 
Feasible Entry -Contains one of the valid speciality codes listed in the 
HCFA Data Users Reference Guide.7  113,394  6.2% 
Unknown Entry - Code is 99.  88  * 
Retired Entry -Code is retired - osteopathic speciality code.  49  * 
Erroneous Entry - Any code other than listed above.  6  * 
Revised Entry -Code is 49 (formerly for a miscellaneous speciality, 
redesignated as an Ambulatory Surgical Center).  1  * 
Secondary Speciality Board Certification Code 
Unknown Entry - Code is U.  1,271,103  69.6% 
Missing Entry - Code is all blanks.  450,819  24.7% 
Feasible Entry - Code is Yor N.  104,157  5.7% 
UPIN Status Code -Deactivated, Resident, Intern, Practice (DRIP) 
Feasible Entry - Code is R, I, or P (Active Practice).  1,826,039  100.0% 
Erroneous Entry - Any code other than listed above.  40  * 
7 Health Care Financing Administration, Data Users Reference Guide, March 1997, Appendix
of Common Codes, pp 75 - 77. 
*Rounds to zero percent. 
23 
Accuracy of UPIN Data  OEI-07-98-00410  Medicare Physician Identification and Eligibility Data Elements
Analysis of the Universe - UPIN Practice Setting (PIN) Data 
Universe  Universe 
Field Identifier / Flag Description  Total1   Percent 
Participation Status Code 
Feasible Entry - Code is Y or N.  1,826,076  100.0% 
Missing Entry - Code is all blanks.  2  * 
Erroneous Entry - Any code other than listed above.  1  * 
Group Practice Indicator 
Feasible Entry - Code is 1 (group) or 4 (solo) practice.  1,824,555  99.9% 
Erroneous Entry - Any code other than listed above.  1,521  0.1% 
Missing Entry - Code is all 0's or blanks.  3  * 
Sanction Code 
Not Sanctioned - Code is all blanks.  1,824,038  99.9% 
Feasible Entry - Code is A to R.8  1,948  0.1% 
Unknown - Code is U, individual is sanctioned but type of sanction action 
is unknown.  93  * 
Sanction Date 
Not Sanctioned - Date code is all blanks.  1,824,430  99.9% 
Feasible Entry - Year code is between 1966 to 1998, and month is valid.  1,531  0.1% 
Erroneous Entry - Any code other than listed above.  118  * 
Sanction Length 
Not Sanctioned - Code is blank or 0.  1,824,442  99.9% 
Feasible Entry - Code for years of sanction is between 1 to 15, 20, 25, 30, 
35, 40, 45, 50, 99.  1,608  0.1% 
Questionable Entry - Code for years of sanction is between 16 to 19, 21 to 
24, 26 to 29, 31 to 34, 36 to 39, 41 to 44, 46 to 49, 51 to 98.  29  * 
Social Security Number 
Feasible Entry  1,319,135  72.2% 
Missing Entry  1  * 
Zero Entry - Code is all 0's or 9's  506,943  27.8% 
8 Medicare Carriers Manual, Professional relations, (Pub. 14 - 4) 1015, Exhibit 4.
* Rounds to zero percent. 
24 
Accuracy of UPIN Data  OEI-07-98-00410  A P P E N D I X  D  
Agency Comments

25 
Accuracy of UPIN Data  OEI-07-98-00410