Department of Health and Human Services 

OFFICE OF 

INSPECTOR GENERAL 

INSPECTOR GENERAL 

July 2003 

OEI-03-01-00380 

Accuracy of Unique Physician/Practitioner 

Identification Number Registry Data 
OFFICE OF INSPECTOR GENERAL

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 OIG’s 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. 
EXECUTIVE SUMMARY 

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 provider’s practice locations and submits the

provider’s 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 CMS’s 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 provider’s 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. 

Accuracy of UPIN Data i 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, CMS’s oversight functions may 

become less effective. For instance, inaccurate UPIN data may jeopardize CMS’s 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 Medicare’s 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 CMS’s 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. 

Accuracy of UPIN Data ii 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 CMS’s comments is presented in 

Appendix C. 

Accuracy of UPIN Data iii OEI-03-01-00380 
TABLE OF CONTENTS 

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

Accuracy of UPIN Data iv OEI-03-01-00380 
INTRODUCTION 

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. 

Accuracy of UPIN Data 1 OEI-03-01-00380 
Carriers are responsible for verifying the information provided in an enrollment application, 

particularly the provider’s 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 applicant’s practice locations and electronically submits the 

applicant’s information to the UPIN Registry. PINs are Medicare billing numbers. One record 

is submitted per PIN, and each record contains a provider’s 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 Association’s 

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 CMS’s 

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 

Accuracy of UPIN Data 2 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 CMS’s 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. 

Accuracy of UPIN Data 3 OEI-03-01-00380 
Table 1. Sample of Health Care Providers and their Associated Practice Settings 

Strata Description UPINs 

in Universe 

UPINs 

in Sample 

PINs 

in Universe 

PINs 

in Sample 

1 Providers with 10 or More 

Practice Settings 8,207 100 108,499 1,314 

2 Providers with Fewer Than 

10 Practice Settings 868,319 400 1,876,491 882 

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 

Accuracy of UPIN Data 4 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 CMS’s UPIN data dictionary. For instance, the UPIN Registry record 

layout allows only six characters for a provider’s middle name. If the provider’s 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 provider’s 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 provider’s 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 President’s Council on Integrity and Efficiency. 

Accuracy of UPIN Data 5 OEI-03-01-00380 
FINDINGS 

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 provider’s 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. 

Accuracy of UPIN Data 6 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, CMS’s 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 Medicare’s 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 CMS’s 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 

Accuracy of UPIN Data 7 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 provider’s 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. 

Accuracy of UPIN Data 8 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. 

Accuracy of UPIN Data 9 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 provider’s 

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. 

Accuracy of UPIN Data 10 OEI-03-01-00380 
CONCLUSION 

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, CMS’s 

oversight functions may become less effective. For instance, inaccurate UPIN data may 

jeopardize CMS’s 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 Medicare’s 

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 

CMS’s 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. 

RECOMMENDATIONS 

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. 

Accuracy of UPIN Data 11 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. 

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 CMS’s comments is presented in 

Appendix C. 

Accuracy of UPIN Data 12 OEI-03-01-00380 
APPENDIX A 

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

Accuracy of UPIN Data 13 OEI-03-01-00380 
APPENDIX A 

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 

Inaccurate Practice Setting Record 

52.49% 46.86% - 58.12% 

Percent of Practice Setting Records Containing at 

Least One Inaccurate Item 

34.95% 31.34% - 38.56% 

Table 2. 

Providers with Inaccurate UPIN Data

by Number of Active Practice Settings Per Provider

Percent of 

Providers 

95% Confidence Interval 

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) 

Accuracy of UPIN Data 14 OEI-03-01-00380 
APPENDIX A 

Table 3. 

UPIN Registry Information That Was Most Often Inaccurate 

Inaccurate Information Percent of Active 

Practice Settings with 

Inaccurate Information 

95% Confidence Interval 

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 

Have Never Been Used or Are No Longer Used 

44.21% 40.47% - 47.95% 

Percent of PINs in Active UPIN Database That 

Have Never Been Used to Bill Medicare 

16.33% 13.61% - 19.05% 

Percent of PINs in Active UPIN Database That 

Are No Longer Used to Bill Medicare 

27.88% 24.49% - 31.27% 

Accuracy of UPIN Data 15 OEI-03-01-00380 
APPENDIX A 

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 

Practice Setting in the Active UPIN Database 

49.01% 43.37% - 54.66% 

Percent of Providers Who No Longer Bill Using 

Any of the PINs in the Active UPIN Database 

16.75% 12.54% - 20.96% 

Percent of Providers with No Active PINs Who 

are Deceased 

13.98% 4.42% - 23.54% 

Percent of Providers with No Active PINs Who 

Are Retired 

25.83% 13.74% - 37.92% 

Table 6. 

Providers Who Could Not Be Contacted by Mail 

Point Estimate 95% Confidence Interval 

Percent of Providers Who Could Not Be 

Contacted by Mail 

8.79% 6.05% - 11.53% 

Percent of Providers Who Could Not Be 

Contacted Who Billed Medicare in 2000 

51.67% 35.32% - 68.02% 

Accuracy of UPIN Data 16 OEI-03-01-00380 
APPENDIX A 

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 

Truncated Middle Names 

3.43% 1.39% - 5.47% 

Percent of Active Practice Settings Containing 

Truncated Street Addresses 

0.64% 0% - 1.52% 

Percent of Active Practice Settings Containing 

School Codes that May Not Be Accurate Due to 

Categorization 

5.58% 3.03% - 8.13% 

Percent of Active Practice Settings Containing 

Credentials that May Not Be Accurate Due to 

Categorization 

5.76% 3.17% - 8.35% 

Accuracy of UPIN Data 17 OEI-03-01-00380 
APPENDIX B 

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 

Accuracy of UPIN Data 18 OEI-03-01-00380 
APPENDIX C 

Comments from the 

Centers for Medicare and Medicaid Services

Accuracy of UPIN Data 19 OEI-03-01-00380 
APPENDIX C 

Accuracy of UPIN Data 20 OEI-03-01-00380 
APPENDIX C 

Accuracy of UPIN Data 21 OEI-03-01-00380 
ACKNOWLEDGMENTS 

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 General’s

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/ 

Accuracy of UPIN Data 22 OEI-03-01-00380