Department of Health and Human Services 
OFFICE OF 
INSPECTOR GENERAL 
Accuracy of Unique Physician/Practitioner 
Identification Number Registry Data 
INSPECTOR GENERAL 
July 2003 
OEI-03-01-00380  O I G
FFICE OF  NSPECTOR  ENERAL

http://www.oig.hhs.gov/ 
The mission of the Office of Inspector General (OIG), as mandated by Public Law 95-452, as amended, 
is to protect the integrity of the Department of Health and Human Services (HHS) programs, as well as 
the health and welfare of beneficiaries served by those programs.  This statutory mission is carried out 
through a nationwide network of audits, investigations, and inspections conducted by the following 
operating components: 
Office of Audit Services 
The OIG's Office of Audit Services (OAS) provides all auditing services for HHS, either by conducting 
audits with its own audit resources or by overseeing audit work done by others.  Audits examine the 
performance of HHS programs and/or its grantees and contractors in carrying out their respective 
responsibilities and are intended to provide independent assessments of HHS programs and operations in 
order to reduce waste, abuse, and mismanagement and to promote economy and efficiency throughout the 
Department. 
Office of Evaluation and Inspections 
The OIG's Office of Evaluation and Inspections (OEI) conducts short-term management and program 
evaluations (called inspections) that focus on issues of concern to the Department, the Congress, and the 
public.  The findings and recommendations contained in the inspections reports generate rapid, accurate, 
and up-to-date information on the efficiency, vulnerability, and effectiveness of departmental programs. 
Office of Investigations 
The OIG's Office of Investigations (OI) conducts criminal, civil, and administrative investigations of 
allegations of wrongdoing in HHS programs or to HHS beneficiaries and of unjust enrichment by 
providers.  The investigative efforts of OI lead to criminal convictions, administrative sanctions, or civil 
monetary penalties.  The OI also oversees State Medicaid fraud control units which investigate and 
prosecute fraud and patient abuse in the Medicaid program. 
Office of Counsel to the Inspector General 
The Office of Counsel to the Inspector General (OCIG) provides general legal services to OIG, rendering 
advice and opinions on HHS programs and operations and providing all legal support in OIGs internal 
operations.  The OCIG imposes program exclusions and civil monetary penalties on health care providers 
and litigates those actions within the Department.  The OCIG also represents OIG in the global settlement 
of cases arising under the Civil False Claims Act, develops and monitors corporate integrity agreements, 
develops model compliance plans, renders advisory opinions on OIG sanctions to the health care 
community, and issues fraud alerts and other industry guidance.  E X E C U T I V E  S U M M A R Y  
OBJECTIVE 
To determine whether information contained in the Unique Physician/Practitioner Identification 
Number database is complete and accurate. 
BACKGROUND 
The Consolidated Omnibus Budget Reconciliation Act of 1985 required the Centers for

Medicare & Medicaid Services (CMS) to establish unique identifiers for all physicians who

provide services to Medicare beneficiaries.  As part of the Medicare enrollment process, CMS

began assigning Unique Physician/Practitioner Identification Numbers (UPINs) to all physicians

who bill or perform services for Medicare payment.  The use of UPINs was later expanded to

include non-physician practitioners and medical group practices. Information on all UPINs is

stored in a national database called the Unique Physician/Practitioner Identification Number

System, also known as the UPIN Registry. The Medicare enrollment process should ensure

that services are performed only by qualified providers and enable CMS to reduce the potential

for inappropriate payments. 

In order to receive a UPIN, a health care provider must enroll with the Medicare 

Part B carrier serving his or her geographic area.  The carrier assigns a separate Provider

Identification Number (PIN) to each of the providers practice locations and submits the

providers information to the UPIN Registry. The Registry then assigns a UPIN to the

provider.  Health care providers must inform the appropriate Part B carrier when changes

occur in their enrollment information.  Carriers are required to maintain and update enrollment

data and deactivate practice settings that are no longer active. 

For this inspection, we selected a stratified random sample of 500 UPINs from CMSs active

UPIN database. We contacted providers and asked them to verify information contained in the

UPIN database for each of their active practice settings.  Each practice setting record contains

a providers biographical data and data specific to the practice location, including the Medicare

billing number. We also reviewed the universe of active UPIN database records to identify

inconsistent, missing, and questionable information. 

i 
Accuracy of UPIN Data  OEI-03-01-00380  FINDINGS 
Fifty-two percent of providers in the active UPIN database had inaccurate 
information in at least one of their practice setting records 
Forty-four percent of PINs have never been used or are no longer used to bill 
Medicare 
Nine percent of providers could not be contacted by mail 
The UPIN record layout and data entry instructions may adversely affect the 
accuracy of data 
By performing an automated review of the entire UPIN database, CMS could 
identify inconsistent, missing, and questionable information 
CONCLUSION AND RECOMMENDATIONS 
We recognize that CMS has made an effort to improve the completeness and accuracy of the UPIN 
Registry. However, the findings of our report demonstrate that the information housed in the UPIN 
Registry continues to be inaccurate. The UPIN Registry is the most comprehensive source of 
information on all health care practitioners who provide services for which payment is made under 
Medicare. When information housed in this Registry is unreliable, CMSs oversight functions may 
become less effective. For instance, inaccurate UPIN data may jeopardize CMSs ability to identify 
unusual billing activity, both in the performance of services and the ordering of services. It may also 
inhibit CMS from verifying that sanctions are correctly imposed. Given that information in the UPIN 
database is used to update Medicares Participating Provider Directory, unreliable UPIN Registry data 
could also adversely affect beneficiaries ability to make informed choices about health care providers. 
Furthermore, CMS intends to use UPIN Registry data to enumerate the National Provider System 
(NPS), which will issue and house new National Provider Identifiers (NPIs).  The creation of these 
standard identifiers was mandated by the Health Insurance Portability and Accountability Act of 1996. 
NPIs will replace UPINs in the Medicare program, and are expected to enhance CMSs ability to 
safeguard Medicare and its beneficiaries against fraud, abuse, and inappropriate payments. However, 
if inaccurate data are used to populate NPS, the new identifiers will not meet their full potential as a 
protection for the Medicare program and the people it serves. 
ii 
Accuracy of UPIN Data  OEI-03-01-00380  We recommend that CMS: 
<	 Correct inaccurate and incomplete information in the UPIN Registry and 
deactivate practice settings that have never been or are no longer used by 
Medicare providers. In addition, CMS and its contractors should periodically 
review data contained in the UPIN Registry to ensure that it is complete, 
accurate, and consistent. Automated reviews can be used to target potentially 
inaccurate data in the UPIN database.  We will provide CMS with information 
regarding the specific inaccuracies we identified in the UPIN Registry. Complete and 
accurate UPIN data are essential given that CMS intends to transfer provider data from 
the UPIN Registry to the NPS. 
<	 Conduct a review of providers who billed Medicare for Part B services in the 
year 2000 but could not be contacted by mail. 
<	 Review and revise existing UPIN Registry data entry guidelines, including 
format requirements and response categories, to ensure that data are accurately 
recorded.  For instance, CMS may want to provide a uniform format for state license 
numbers; expand the length of certain variables, such as street address; and revise the 
categories that carriers use to classify schools, credentials, and specialties. CMS 
should also ensure that changes specified in program memoranda be reflected in the 
Medicare Carriers Manual and that carriers implement those changes. When 
developing the structure of the new NPS, CMS should consider how formatting, space 
allotment, and response categories will affect the accuracy of data. 
AGENCY COMMENTS 
CMS concurred with our recommendations and indicated that they are taking steps to correct 
inaccurate and incomplete information in the UPIN Registry, deactivate inactive Medicare 
billing numbers, review providers who billed Medicare in the year 2000 but could not be 
contacted by mail, and review and revise existing UPIN Registry data entry guidelines. CMS 
recently developed a UPIN Registry quality assurance plan to improve the accuracy of data in 
the UPIN Registry. In an effort to enhance existing UPIN data and obtain information needed 
for the NPS, CMS intends to purchase, validate, and replace UPIN information currently 
identified as inaccurate, missing, and incomplete. In addition, CMS will instruct Medicare 
contractors to improve UPIN reporting through education and training; update the UPIN 
instructions contained in the Medicare Carriers Manual; develop consistency edits; and increase 
monitoring of contractors UPIN activities. The full text of CMSs comments is presented in 
Appendix C. 
iii 
Accuracy of UPIN Data  OEI-03-01-00380  T A B L E  O F  C O N T E N T S  
PAGE

EXECUTIVE SUMMARY ...................................................... i

INTRODUCTION .............................................................1

FINDINGS

Providers Report Inaccurate UPIN Data  .......................................6

PINs That Have Never Been Used or Are No Longer Used ......................... 7

Providers Who Could Not Be Contacted  ......................................8

UPIN Record Layout and Data Entry Guidelines May Adversely Affect Data ............ 8

Using Automated Reviews to Identify Inconsistent, Missing, and Questionable Data ........9 

CONCLUSION  ............................................................. 11

RECOMMENDATIONS ...................................................... 11

AGENCY COMMENTS  ...................................................... 12

APPENDICES

A: Estimates and Confidence Intervals  ........................................13

B: Frequency of Inaccurate Items ............................................18

C: Comments from the Centers for Medicare & Medicaid Services ................... 19

ACKNOWLEDGMENTS ..................................................... 22

iv 
Accuracy of UPIN Data  OEI-03-01-00380  I N T R O D U C T I O N  
OBJECTIVE 
To determine whether information contained in the Unique Physician/Practitioner Identification 
Number database is complete and accurate. 
BACKGROUND 
Overview of UPIN Registry Data 
The Consolidated Omnibus Budget Reconciliation Act of 1985 required the Centers for 
Medicare & Medicaid Services (CMS) to establish unique identifiers for all physicians who 
provide services to Medicare beneficiaries.  As part of the Medicare enrollment process, CMS 
began assigning Unique Physician/Practitioner Identification Numbers (UPINs) to all physicians 
who bill or perform services for Medicare payment, or who order services that result in 
Medicare payment.  The use of UPINs was later expanded to include non-physician 
practitioners and medical group practices. 
Information on all UPINs is stored in a national database called the Unique 
Physician/Practitioner Identification Number System, or UPIN Registry. CMS contracts with a 
single Medicare Part B carrier to maintain the UPIN Registry.  The Medicare enrollment 
process is designed to ensure that Medicare beneficiaries are receiving services performed only 
by qualified providers. It may also enable CMS to reduce the potential for inappropriate 
payments. By summarizing data by UPINs, CMS can identify aberrant ordering and billing 
patterns.  In addition, information in the UPIN Registry, such as providers names, credentials, 
addresses, and specialties, is used to update the Participating Physician Directory, an internet 
tool designed to assist Medicare beneficiaries in locating appropriate providers.  This 
information is directly available to the public via the Medicare website. 
Provider Enrollment 
In order to receive a UPIN, a health care provider must complete and submit an enrollment 
application to the Medicare Part B carrier serving his or her geographic area.  If the provider 
intends to bill for services in multiple carrier jurisdictions, a separate enrollment form must be 
sent to each carrier.  Enrollment forms require applicants to provide carriers with biographical 
information such as full name, Social Security number, education, medical specialties, and state 
licensing information.  Applicants must also provide information for each of their practice 
settings (i.e., physical locations where they provide medical services), including business and 
billing addresses. 
1 
Accuracy of UPIN Data  OEI-03-01-00380  Carriers are responsible for verifying the information provided in an enrollment application, 
particularly the providers credentials, state license, certifications, and sanctions. Upon 
completion of the verification process, the carrier assigns a separate Provider Identification 
Number (PIN) to each of the applicants practice locations and electronically submits the 
applicants information to the UPIN Registry. PINs are Medicare billing numbers. One record 
is submitted per PIN, and each record contains a providers biographical data as well as data 
specific to the practice location. 
The UPIN Registry contractor then performs additional validation checks on providers 
records. These checks include comparisons against the American Medical Associations 
database of physicians. If the Registry contractor identifies discrepancies in or across records, 
a notice is sent to the responsible carrier who investigates the issue, makes the appropriate 
changes, and resubmits the record to the Registry.  If no discrepancies are identified, the 
Registry assigns a UPIN to the provider. Each provider is assigned only one UPIN; however, 
providers may have multiple listings in the UPIN Registry depending upon the number of PINs 
assigned to them. 
Maintenance of UPIN Registry Data 
The enrollment application instructs health care providers to alert the appropriate Part B carrier 
to any changes in enrollment information within 90 days of the effective date of the change. 
According to the Medicare Carriers Manual, carriers should maintain provider enrollment data 
and notify the Registry within 5 days of any additions, changes, or deletions reported by 
providers.  The Registry contractor also periodically reviews the UPIN database and notifies 
carriers about the suspected death or sanction of a provider.  Carriers then have 30 days to 
update the file accordingly. Ultimately, Medicare requires that provider information in the 
UPIN Registry be identical to information in the carriers administrative files. 
Carriers are also responsible for deactivating practice setting records that have had no 
Medicare claims activity for 12 consecutive months. A UPIN remains active as long as there is 
claims activity from at least one associated practice setting.  If there is no claims activity from 
any of the practice settings for 12 consecutive months, the UPIN becomes inactive as well. 
CMS divides the UPIN Registry into two files, one containing active records and the other 
containing inactive records. Both of these files are updated on a monthly basis. 
Previous OIG Work Involving UPINs 
The Office of Inspector General (OIG) has issued several reports relating to UPINs. These 
reports address the accuracy of UPIN data as well as the use of inactive and invalid UPINs on 
Part B claims. In 1999, the OIG issued a report entitled Accuracy of Unique Physician 
Identification Number Data (OEI-07-98-00410).  This report found that, despite CMSs 
efforts to enhance the accuracy of information contained in the UPIN Registry, problems with 
the data persisted. For instance, 88 percent of state license numbers in the UPIN Registry did 
not exactly match license numbers provided by state 
2 
Accuracy of UPIN Data  OEI-03-01-00380  licensing boards;  28 percent of records did not contain a Social Security number; and almost 
one-fourth of the active UPINs had no claims activity for 12 months.  This report also found 
inconsistencies in providers biographical information across different practice setting records. 
Additional problems were identified by a 2001 report, Inaccuracies in the Unique Physician 
Identification Number Registry: Incorrect Addresses for Mental Health Service Providers 
(OEI-03-99-00131). According to this report, addresses listed in the UPIN Registry database 
were inaccurate for 28 percent of providers, and carriers did not always have correct 
addresses for the providers. Another 2001 report, Medical Equipment and Supply Claims 
with Invalid or Inactive Physician Numbers (OEI-03-01-00110), found that Medicare paid 
$32 million for medical equipment and supply claims with invalid UPINs in 1999. It also found 
that Medicare paid $59 million in 1999 for medical equipment and supply claims with UPINs 
that were inactive on the date of service. 
National Provider Identifier Initiative 
For the purposes of administrative simplification, the Health Insurance Portability and 
Accountability Act of 1996 mandated the adoption of a standard, unique health identifier for 
each individual, employer, health plan, and health care provider for use in the health care 
system.  These identifiers, known as National Provider Identifiers (NPIs), will be issued by the 
National Provider System (NPS).  The new identifiers are designed to facilitate the exchange of 
provider data across health plans and assist in the prevention of fraud, abuse, and inappropriate 
payments in health care programs. NPIs will eventually replace UPINs in the Medicare 
program. At this time, CMS intends to use UPIN Registry data to initially populate the NPS. 
To ensure an effective transition to the new provider identifier system, CMS and its contractors 
have taken steps to improve the accuracy of the UPIN file.  Program memoranda issued in 
1998 and 2000 instruct Part B carriers to deactivate inactive practice settings and update 
UPIN Registry records with correct addresses, states of licensure, school codes, dates of birth, 
and specialties. 
METHODOLOGY 
Sample Design 
We obtained an August 2001 copy of CMSs active UPIN database containing information 
about UPINs and their associated PINs. Each PIN represents a unique practice setting. We 
divided the universe of active UPINs for individual health care providers into two strata based 
on the number of active practice settings associated with each provider.  The first stratum 
consisted of providers with 10 or more active practice settings, and the second stratum 
consisted of providers with less than 10 active practice settings.  We selected a random sample 
of 100 UPINs from the first stratum and 400 UPINs from the second stratum for a total sample 
of 500 UPINs.  We then selected all of the active practice setting records associated with each 
of the sample providers. A description of the sample is provided in Table 1 on the next page. 
3 
Accuracy of UPIN Data  OEI-03-01-00380  Table 1. Sample of Health Care Providers and their Associated Practice Settings 
Strata  Description  UPINs  UPINs  PINs  PINs 
in Universe  in Sample  in Universe  in Sample 
1  Providers with 10 or More 
8,207  100  108,499  1,314 
Practice Settings 
2  Providers with Fewer Than 
868,319  400  1,876,491  882 
10 Practice Settings 
Total  876,526  500  1,984,990  2,196 
Data Collection 
We obtained sample providers current mailing addresses from Part B carriers, or when carrier 
addresses were incorrect or unavailable, from the UPIN file. We contacted sample providers 
by overnight mail and asked them to verify information contained in the UPIN database for 
each of their active practice settings.  We made up to three written attempts to contact 
providers. Providers were asked to verify the following information: UPIN, name, Social 
Security number, credentials, date of birth, professional school, year of graduation, specialties, 
certifications, state licensing information, group practice participation, Medicare participation, 
practice setting addresses, whether PINs were ever used to bill Medicare, and whether PINs 
are currently used to bill Medicare. If providers identified any inaccurate information, we asked 
them to provide us with the correct information. 
We received responses from 387 of the 500 providers in our sample. However, responses 
from 22 of these providers were not included in our analysis.  Of these 22 providers, responses 
from 13 did not contain information sufficient for analysis, and responses from 9 were received 
after the data collection cutoff.  Responses from the remaining 365 providers were used as the 
basis for the analysis of sample data.  The 365 providers in our sample represent 652,342 
providers and 1,400,476 practice settings in the universe. 
We did not receive responses from 65 providers after 3 written requests.  We were unable to 
contact the remaining 48 providers because the mailing addresses provided by carriers or the 
UPIN database were incorrect or insufficient, and our mailings were returned as undeliverable. 
Data Analysis 
Analysis of sample data. We analyzed sample providers responses to determine whether 
providers could verify their UPINs, whether providers have ever used their PINs to bill 
Medicare, and whether providers currently use their PINs to bill Medicare.  We did not 
determine whether providers notified carriers about PINs that they never or no longer use. We 
identified inaccurate information only for those PINs that providers reported using at the time of 
our review. There were 21 data elements used in our analysis of inaccurate information 
included in the UPIN Registry database.  According to the UPIN 
4 
Accuracy of UPIN Data  OEI-03-01-00380  record layout outlined in the Carriers Manual, 18 of the 21 data elements are required. The 
remaining three data elements (primary specialty certification, secondary speciality, and 
secondary specialty certification) should be included in the UPIN Registry if available. 
When providers identified inaccurate information, we asked them to provide us with correct 
information.  When reviewing this corrected information, we identified cases where data 
contained in the UPIN Registry was inaccurate due only to certain restrictions imposed by 
either the UPIN file record layout or the data entry guidelines specified in the Medicare 
Carriers Manual or CMSs UPIN data dictionary. For instance, the UPIN Registry record 
layout allows only six characters for a providers middle name.  If the providers middle name 
exceeded six characters, the name was truncated and the provider indicated that the truncated 
name was incorrect. We recoded these types of responses to capture issues relating to record 
layout and data entry guidelines.  We did not consider these cases to be inaccurate. 
We estimated the proportion of practice setting records with inaccurate information, as well as 
the proportion of sample UPINs with at least one inaccurate practice setting record.  In 
addition, we determined whether providers with a large number of practice locations are more 
likely to have inaccurate information in their records. 
The results of our analysis of sample data are projectable to the responding universe. Point 
estimates and confidence intervals for all statistics presented in the findings of this report are 
provided in Appendix A. 
Analysis of all active UPIN records. We reviewed the universe of active UPIN Registry 
records to identify instances where the content and format of a providers biographical 
information was inconsistent from one practice setting to the next. We also analyzed the entire 
active UPIN Registry database to determine whether the universe of UPIN Registry records 
contained any missing or questionable entries.  We reviewed records to determine if entries for 
the following information were either missing or questionable: name, address, date of birth, 
header Social Security number (the Social Security number submitted with the providers initial 
practice setting), credentials, state license, professional school code, graduation year, primary 
specialty code, secondary specialty code, resident/intern status, and practitioner type. 
This inspection was conducted in accordance with the Quality Standards for Inspections 
issued by the Presidents Council on Integrity and Efficiency. 
5 
Accuracy of UPIN Data  OEI-03-01-00380  F I N D I N G S  
Our review of the entire active UPIN Registry (1,984,990 records) revealed that the UPIN 
database contained inconsistent, incomplete, and questionable data. Furthermore, a review of 
responses from a stratified random sample of 500 Medicare providers, who were asked to 
verify information contained in the UPIN Registry for each of their active practice settings, 
found that the UPIN Registry also contains inaccurate information. The combination of these 
findings provides strong evidence that the UPIN Registry contains unreliable information. 
Unreliable UPIN Registry data undermines the effectiveness of the Medicare claims review 
process. It may also lead to the provision of erroneous information to Medicare beneficiaries. 
Moreover, unreliable UPIN Registry information may be transferred into the new National 
Provider System (NPS).  The National Provider Identifiers (NPIs) housed in this new system 
are expected to prevent fraud, abuse, and inappropriate payments. However, if inaccurate 
data are used to populate the system, the new national identifiers will not meet their full potential 
as a program safeguard. 
Fifty-two percent of providers in the active UPIN database had 
inaccurate information in at least one of their practice setting 
records 
Based on our sample, we estimate that over half of providers listed in the active UPIN database 
had at least one practice setting record with inaccurate information.  Providers can have one or 
more practice settings in the UPIN database. In our sample, the number of active practice 
settings per provider ranged from 1 to 30. Providers with a higher number of practice settings 
(10 or more) were more likely to have active UPIN Registry records with inaccurate 
information. 
We estimate that 35 percent of all practice setting records in the active UPIN database 
contained at least one inaccurate item; and the number of incorrect items on individual 
inaccurate practice setting records ranged from 1 to 9. We identified inaccurate information 
only for those practice settings that providers reported using at the time of our review. 
Information that was most often inaccurate included: whether the provider is certified in his/her 
primary specialty, the providers secondary specialty, whether the provider is certified in his/her 
secondary specialty, professional school, state license number, and Social Security number. 
Addresses for practice locations (street, city, zip code) were often inaccurate as well. Table 2 
on the next page shows the items that were most frequently inaccurate, and Appendix B 
provides a complete listing of inaccurate items. 
6 
Accuracy of UPIN Data  OEI-03-01-00380  Table 2. UPIN Registry Information That Was Most Often Inaccurate 
Inaccurate Information  Percent of Active Practice Settings with 
Inaccurate Information 
Primary Specialty Certification  32.61% 
Secondary Specialty  23.16% 
Secondary Specialty Certification  18.15% 
Street Address of Practice Location  17.48% 
Zip Code of Practice Location  13.40% 
Professional School  10.98% 
State License Number  9.69% 
Group Practice Participation  8.91% 
Medicare Participation Status  6.60% 
Primary Specialty  5.31% 
Social Security Number  5.11% 
Source: Analysis of sample providers responses from 2001 OIG survey 
When information in the UPIN Registry is inaccurate, CMS cannot effectively identify aberrant 
ordering and billing activity. For example, CMSs contractors have used specialty information 
to identify cases where psychiatrists were listed as ordering physicians on Medicare claims for 
wheelchairs.  Psychiatrists would not typically order wheelchairs for beneficiaries.  If specialty 
information in the UPIN Registry is inaccurate, CMS may not be able to correctly identify this 
kind of aberrant ordering activity.  CMS could also use practice location address information in 
the UPIN file to identify cases where physicians bill or order services for beneficiaries who live 
a significant distance from any of the physician offices. However, CMS may not be able to 
detect these unusual cases if address information in the UPIN Registry is inaccurate. In 
addition, inaccurate provider names, credentials, addresses, and specialties in the UPIN 
database may prevent beneficiaries who use Medicares Participating Provider Directory from 
making informed choices about health care providers.  Finally, inaccurate UPIN Registry data 
may be used to populate the NPS.  This would compromise CMSs ability to use the new 
identifiers contained in the NPS to safeguard Medicare against fraud and abuse. 
Forty-four percent of PINs have never been used or are no 
longer used to bill Medicare 
An estimated 619,105 of 1,400,476 practice settings (44 percent) should no longer be in the 
active UPIN database. According to providers responses, 16 percent of PINs listed in the 
active UPIN database have never been used to bill for Medicare services. Providers also 
reported that an additional 28 percent of active PINs are no longer being used to 
7 
Accuracy of UPIN Data  OEI-03-01-00380  bill Medicare and should therefore be deactivated. Forty-nine percent of providers had at least 
one inactive practice setting in the active UPIN Registry. 
Seventeen percent of providers no longer bill Medicare using any of the PINs listed in the 
active UPIN file. Of these providers, over 14 percent are deceased, and 26 percent indicated 
they had retired. A providers UPIN should be deactivated if all of the practice settings 
associated with that UPIN are no longer active. 
Nine percent of providers could not be contacted by mail 
We were unable to contact 9 percent of providers due to incorrect or insufficient address 
information either provided by Medicare Part B carriers or listed in the UPIN database. More 
than half (52 percent) of these providers billed Medicare for Part B services in the year 2000. 
Actual Medicare payments to sample providers who could not be contacted by mail ranged 
from $34 to $513,255 in the year 2000, with one-quarter of providers receiving more than 
$40,000 in payments. 
For most of the providers who could not be reached, we used every practice location address 
listed in the active UPIN Registry in our attempt to make contact. Although we did not include 
the practice setting records for these providers in our analysis of inaccurate UPIN data, we 
believe the mail returns indicate that address information in the UPIN Registry may not have 
been complete and accurate for these providers. 
The UPIN record layout and data entry instructions may 
adversely affect the accuracy of data 
Information contained in the UPIN Registry could be construed as inaccurate due to data entry 
guidelines specified in the Medicare Carriers Manual. In some cases, formatting instructions or 
space allotment affected the accuracy of data. In other cases, the accuracy of information was 
affected by the categories that carriers use to classify data. Because carriers appear to have 
been following the data entry guidelines when inputting this information, we did not include these 
items in our error rate for inaccurate records. 
Formatting.  Some of the state license numbers contained in the active UPIN Registry were 
adversely affected by formatting requirements.  The Medicare Carriers Manual stipulates that 
entries for state license number should be 12 characters in length, right justified, and preceded 
by zeros.  For example, we found that the license number 35-07-8566-Y was input as 
00035078566Y, a change that could make the number difficult to verify with state licensing 
agencies. A January 1998 program memorandum (B-98-3) issued by CMS confirms this 
conclusion, stating that the convention is creating a problem in identifying the correct license 
number.  Although this memorandum instructs carriers to left justify license numbers and to 
eliminate leading zeros, there has been no change to the data entry guidelines outlined in the 
Carriers Manual. 
8 
Accuracy of UPIN Data  OEI-03-01-00380  Restrictions regarding the length of certain variables could also produce errors in UPIN 
Registry records.  Three percent of practice settings that were currently used by providers 
contained middle names that were truncated either because the UPIN record layout allows only 
six characters for that field or because carriers entered the first initial only.  The UPIN record 
layout allows only 25 characters for street address, a restriction that caused 1 percent of active 
practice setting records to lose important information, such as suite numbers. 
Categorization.  The accuracy of some information may be affected by the categories that 
carriers use to classify data. Six percent of practice settings currently used by providers 
contained school codes that may not accurately reflect the specific schools attended by 
Medicare providers.  Although carriers use specific codes to identify schools for medical 
doctors, osteopaths, chiropractors, podiatrists, and optometrists, they use only general codes to 
categorize foreign schools, nursing schools, dental schools, and schools attended by other types 
of health care providers. Carriers also use a limited list of codes to record providers 
professional credentials.  For 6 percent of active practice settings, the codes used to classify 
credentials may not accurately capture providers qualifications. For instance, two providers 
listed their credentials as CRNA (certified registered nurse anesthetist).  However, this 
credential was not a code that carriers could use. The contractor for one of these providers 
recorded the credential as CNA, which the UPIN data dictionary defines as certified nurse 
anesthetist.  The contractor for the other provider recorded the credential as RNA, which 
the UPIN data dictionary defines as certified registered nurse. Similar categorization 
problems can occur with primary and secondary specialty codes. 
By performing an automated review of the entire UPIN 
Regsitry, CMS could identify inconsistent, missing, and 
questionable information 
According to our own automated review of the universe of active UPIN Registry records, 19 
percent of providers in the UPIN Registry had one or more of the following problems: at least 
one active practice setting record with missing data, at least one active practice setting record 
with questionable data, or biographical information that was inconsistent from one practice 
setting to the next. Although an automated review would not detect all of the inaccurate UPIN 
information that could be found by verifying information with providers, computer programs 
could easily identify missing, questionable, and inconsistent data. 
Missing data. According to our analysis of the entire UPIN database, required information 
was not always recorded in practice setting records. Sixteen percent of providers had at least 
one active practice setting record with missing information. Missing information included Social 
Security numbers, street addresses of practice locations, and cities of practice locations. 
9 
Accuracy of UPIN Data  OEI-03-01-00380  Questionable data. One percent of providers in the active UPIN Registry had at least one 
record that contained either questionable data or data that did not comply with data entry 
guidelines. Examples of questionable entries include school codes that are not specified in the 
Medicare Carriers Manual, implausible dates of birth, and implausible graduation years. 
Inconsistent data. An analysis of the entire active UPIN database revealed that a providers 
biographical information, such as credentials, resident/intern status, and practitioner type, was 
not always consistent from one practice setting to the next.  Two percent of providers had 
UPIN data that was not consistent across all of their practice settings. 
10 
Accuracy of UPIN Data  OEI-03-01-00380  C O N C L U S I O N  
We recognize that CMS has made an effort to improve the completeness and accuracy of the 
UPIN Registry. However, the findings of our report demonstrate that the information housed in 
the UPIN Registry continues to be inaccurate. The UPIN Registry is the most comprehensive 
source of information on all health care practitioners who provide services for which payment is 
made under Medicare.  When information housed in this Registry is unreliable, CMSs 
oversight functions may become less effective.  For instance, inaccurate UPIN data may 
jeopardize CMSs ability to identify unusual billing activity, both in the performance of services 
and the ordering of services.  It may also inhibit CMS from verifying that sanctions are correctly 
imposed. Given that information in the UPIN database is used to update Medicares 
Participating Provider Directory, unreliable UPIN Registry data could also adversely affect 
beneficiaries ability to make informed choices about health care providers.  Furthermore, 
CMS intends to use UPIN Registry data to enumerate the National Provider System (NPS), 
which will issue and house new National Provider Identifiers (NPIs). The creation of these 
standard identifiers was mandated by the Health Insurance Portability and Accountability Act of 
1996. NPIs will replace UPINs in the Medicare program, and are expected to enhance 
CMSs ability to safeguard Medicare and its beneficiaries against fraud, abuse, and 
inappropriate payments. However, if inaccurate data are used to populate NPS, the new 
identifiers will not meet their full potential as a protection for the Medicare program and the 
people it serves. 
R E C O M M E N D A T I O N S  
We recommend that CMS: 
<	 Correct inaccurate and incomplete information in the UPIN Registry and 
deactivate practice settings that have never been or are no longer used by 
Medicare providers. In addition, CMS and its contractors should periodically 
review data contained in the UPIN Registry to ensure that it is complete, 
accurate, and consistent. Automated reviews can be used to target potentially 
inaccurate data in the UPIN database.  We will provide CMS with information 
regarding the specific inaccuracies we identified in the UPIN Registry. Complete and 
accurate UPIN data are essential given that CMS intends to transfer provider data from 
the UPIN Registry to the NPS. 
<	 Conduct a review of providers who billed Medicare for Part B services in the 
year 2000 but could not be contacted by mail. 
11 
Accuracy of UPIN Data  OEI-03-01-00380  <	 Review and revise existing UPIN Registry data entry guidelines, including 
format requirements and response categories, to ensure that data are accurately 
recorded.  For instance, CMS may want to provide a uniform format for state license 
numbers; expand the length of certain variables, such as street address; and revise the 
categories that carriers use to classify schools, credentials, and specialties. CMS 
should also ensure that changes specified in program memoranda be reflected in the 
Medicare Carriers Manual and that carriers implement those changes. When 
developing the structure of the new NPS, CMS should consider how formatting, space 
allotment, and response categories will affect the accuracy of data. 
A G E N C Y  C O M M E N T S  
CMS concurred with our recommendations and indicated that they are taking steps to correct 
inaccurate and incomplete information in the UPIN Registry, deactivate inactive Medicare 
billing numbers, review providers who billed Medicare in the year 2000 but could not be 
contacted by mail, and review and revise existing UPIN Registry data entry guidelines. CMS 
recently developed a UPIN Registry quality assurance plan to improve the accuracy of data in 
the UPIN Registry. In an effort to enhance existing UPIN data and obtain information needed 
for the NPS, CMS intends to purchase, validate, and replace UPIN information currently 
identified as inaccurate, missing, and incomplete. In addition, CMS will instruct Medicare 
contractors to improve UPIN reporting through education and training; update the UPIN 
instructions contained in the Medicare Carriers Manual; develop consistency edits; and increase 
monitoring of contractors UPIN activities. The full text of CMSs comments is presented in 
Appendix C. 
12 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XA   
Estimates and Confidence Intervals

PAGE 
TABLE 1.  Providers and Practice Settings with Inaccurate UPIN Data  ................... 14

TABLE 2. 	 Providers with Inaccurate UPIN Data by Number of Active Practice Settings 

Per Provider  ......................................................14

TABLE 3.  UPIN Registry Information That Was Most Often Inaccurate  .................. 15

TABLE 4.	 PINs in Active UPIN Database That Have Never Been Used or 

Are No Longer Used ................................................15

TABLE 5.  Providers with Inactive Practice Settings in the Active UPIN Database  ........... 16

TABLE 6.  Providers Who Could Not Be Contacted by Mail ...........................16

TABLE 7.  Information in Active Practice Settings That May Be Inaccurate 

Due to UPIN Data Entry Guidelines .....................................17

13 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XA   
Estimates and Confidence Intervals

The tables below contain statistical estimates presented in the Findings section of this report. These 
estimates are weighted based on the stratified random sample design and are reported at the 95 percent 
confidence level. 
Table 1. 
Providers and Practice Settings with Inaccurate UPIN Data 
Point Estimate  95% Confidence Interval 
Percent of Providers with at Least One  52.49%  46.86% - 58.12% 
Inaccurate Practice Setting Record 
Percent of Practice Setting Records Containing at  34.95%  31.34% - 38.56% 
Least One Inaccurate Item 
Table 2. 
Providers with Inaccurate UPIN Data

by Number of Active Practice Settings Per Provider

Percent of  95% Confidence Interval 
Providers 
10 or More Practice Settings  68.66%  57.47% - 79.85% 
Less Than 10 Practice Settings  52.35%  46.67% - 58.03% 
Difference between percentages is significant at above the 95% confidence level. (Chi-square statistic=6.49, df=1, p=0.011) 
14 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XA   
Table 3. 
UPIN Registry Information That Was Most Often Inaccurate 
Inaccurate Information  Percent of Active  95% Confidence Interval 
Practice Settings with 
Inaccurate Information 
Primary Specialty Certification  32.61%  27.42% - 37.80% 
Secondary Specialty  23.16%  17.95% - 28.37% 
Secondary Specialty Certification  18.15%  13.39% - 22.91% 
Street Address of Practice Location  17.48%  13.31% - 21.65% 
Zip Code of Practice Location  13.40%  9.64% - 17.16% 
Professional School  10.98%  7.53% - 14.43% 
State License Number  9.69%  6.44% - 12.94% 
Group Practice Participation  8.91%  5.72% - 12.10% 
Medicare Participation Status  6.60%  3.86% - 9.34% 
Primary Specialty  5.31%  2.86% - 7.76% 
Social Security Number  5.11%  2.68% - 7.54% 
Table 4. 
PINs in Active UPIN Database 
That Have Never Been Used or Are No Longer Used 
Point Estimate  95% Confidence Interval 
Percent of PINs in Active UPIN Database That  44.21%  40.47% - 47.95% 
Have Never Been Used or Are No Longer Used 
Percent of PINs in Active UPIN Database That  16.33%  13.61% - 19.05% 
Have Never Been Used to Bill Medicare 
Percent of PINs in Active UPIN Database That  27.88%  24.49% - 31.27% 
Are No Longer Used to Bill Medicare 
15 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XA   
Table 5. 
Providers with Inactive Practice Settings in the Active UPIN Database 
Point Estimate  95% Confidence Interval 
Percent of Providers with at Least One Inactive  49.01%  43.37% - 54.66% 
Practice Setting in the Active UPIN Database 
Percent of Providers Who No Longer Bill Using  16.75%  12.54% - 20.96% 
Any of the PINs in the Active UPIN Database 
Percent of Providers with No Active PINs Who  13.98%  4.42% - 23.54% 
are Deceased 
Percent of Providers with No Active PINs Who  25.83%  13.74% - 37.92% 
Are Retired 
Table 6. 
Providers Who Could Not Be Contacted by Mail 
Point Estimate  95% Confidence Interval 
Percent of Providers Who Could Not Be  8.79%  6.05% - 11.53% 
Contacted by Mail 
Percent of Providers Who Could Not Be  51.67%  35.32% - 68.02% 
Contacted Who Billed Medicare in 2000 
16 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XA   
Table 7. 
Information in Active Practice Settings That May Be Inaccurate 
Due to UPIN Data Entry Guidelines 
Point Estimate  95% Confidence Interval 
Percent of Active Practice Settings Containing  3.43%  1.39% - 5.47% 
Truncated Middle Names 
Percent of Active Practice Settings Containing  0.64%  0% - 1.52% 
Truncated Street Addresses 
Percent of Active Practice Settings Containing  5.58%  3.03% - 8.13% 
School Codes that May Not Be Accurate Due to 
Categorization 
Percent of Active Practice Settings Containing  5.76%  3.17% - 8.35% 
Credentials that May Not Be Accurate Due to 
Categorization 
17 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XB   
Frequency of Inaccurate Information in the UPIN Registry

Inaccurate Information  Percent of Active Practice Settings 
with Inaccurate Information 
Primary Specialty Certification  32.61% 
Secondary Specialty  23.16% 
Secondary Specialty Certification  18.15% 
Street Address of Practice Location  17.48% 
Zip Code of Practice Location  13.40% 
Professional School  10.98% 
State License Number  9.69% 
Group Practice Participation  8.91% 
Medicare Participation Status  6.60% 
Primary Specialty  5.31% 
Social Security Number  5.11% 
City of Practice Location  4.87% 
Date of Birth  4.46% 
Year of Graduation  2.26% 
Middle Name  1.80% 
First Name  1.60% 
Last Name  1.28% 
Suffix  0.78% 
Credentials  0.64% 
State of Practice Location  0.64% 
State of Licensure  0.32% 
Source: Analysis of sample providers responses from 2001 OIG Survey 
18 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XC   
Comments from the 

Centers for Medicare and Medicaid Services

19 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XC   
20 
Accuracy of UPIN Data  OEI-03-01-00380  A P P E N D I XC   
21 
Accuracy of UPIN Data  OEI-03-01-00380  A C K N O W L E D G M E N T S  
This report was prepared under the direction of Robert A. Vito, Regional Inspector General for 
Evaluation and Inspections in Philadelphia, and Linda M. Ragone, Deputy Regional Inspector General. 
Other principal Office of Evaluation and Inspections staff who contributed include: 
Lauren McNulty, Project Leader 
Jana Garber, Program Analyst 
Tricia Davis, Program Specialist 
Bambi Straw, Program Specialist 
For information or copies of this report, please contact

the Office of Inspector Generals

Public Affairs office at (202) 619-1343.

Reports are also available on the World Wide Web at our home page address:

http://www.oig.hhs.gov/ 
22 
Accuracy of UPIN Data  OEI-03-01-00380