Michael F. Mangano /s/

Principal Deputy Inspector General

OIG Final Report: “Inaccuracies in the Unique Physician Identification Number Registry:

Incorrect Addresses for Mental Health Service Providers,” OEI-03-99-00131

Thomas Scully

Administrator

Centers for Medicare & Medicaid Services

SUMMARY 

The purpose of this memorandum is to present the Centers for Medicare & Medicaid Services 

(CMS) with information regarding the inaccuracy of provider data contained in the Unique 

Physician/Practitioner Identification Number (UPIN) Registry. We identified inaccurate 

addresses in the UPIN Registry for 28 percent of the providers in our sample during the course 

of an inspection assessing the appropriateness of Medicare Part B payments for outpatient 

mental health services. Even the Medicare carriers did not have correct addresses for all of 

these providers. We estimate that Medicare paid about $35 million (± $17 million) in 1998 for 

outpatient mental health services billed by providers with inaccurate mailing addresses. 

We recommend that CMS take steps to validate and update UPIN Registry data. 

BACKGROUND 

Unique Provider Identification Number Registry. The Consolidated Omnibus Budget 

Reconciliation Act of 1985 required CMS to establish a unique identifier for all physicians who 

provide services to Medicare beneficiaries. Since that time, CMS has assigned Unique 

Physician Identification Numbers (UPINs) to physicians who bill or perform services for 

Medicare payment, and established a database of physician enrollment information known as 

the UPIN Registry. In 1994, the Registry was expanded to include non-physician practitioners 

and group practices. The CMS contracts with a single carrier to maintain the Registry of 

providers who bill Medicare Part B. 

To obtain a UPIN, each health care practitioner or group practice must submit an application for 

enrollment in the Medicare program to the appropriate carrier. Currently, CMS has 

standardized provider enrollment and update forms for all carriers. As part of the enrollment 

process, practitioners must provide carriers with information such as full name; State in which 

the applicant is licensed or practicing; license, registration, or certification number; tax 

identification number; and mailing address for Medicare-related correspondence. Providers 

often furnish or bill for services from several locations in different carrier jurisdictions. 

Therefore, applicants must also provide an address for each practice setting where services are 

rendered, as well as a “pay to” address for each practice setting. 
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Carriers validate the information contained in the enrollment application and assign a Provider 

Identification Number (PIN) for each of the applicant’s practice settings. The carrier then 

submits this information to the UPIN Registry. Additional data entry checks are performed by 

the Registry contractor and a UPIN is assigned to the practitioner. While practitioners may have 

more than one PIN (indicating more than one practice setting), they have only one UPIN. The 

Registry maintains data on each PIN under a provider’s UPIN. 

Once the Registry assigns a UPIN, the carrier is responsible for maintaining provider enrollment 

data and promptly notifying the UPIN Registry of changes, additions, or deletions reported by 

providers. According to the Medicare Carriers’ Manual, provider information in the Registry 

must be identical to provider information in carrier files, including all mailing, practice setting, 

and “pay to” addresses. Also, carriers must deactivate practice settings that have no Medicare 

claims activity for 12 consecutive months. 

Implementation Plan for the National Provider Identifier. For 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.”1 These identifiers, known as National 

Provider Identifiers (NPIs), will be issued by the National Provider System. According to CMS, 

Medicare provider enrollment information contained in the UPIN Registry “will be loaded into 

the National Provider System and NPIs will be assigned automatically to Medicare providers.”2 

The NPIs would then replace UPINs in the Medicare program. 

Unique Provider Number Issues Previously Identified by the OIG. Over the past 10 years, 

the Office of Inspector General (OIG) has issued several reports identifying problems with the 

completeness and accuracy of provider enrollment information in carriers’ files and the UPIN 

Registry. Between 1991 and 1992, the OIG found that some carriers did not require physicians 

to provide billing addresses on applications for enrollment. The OIG also found that many 

carriers were not updating provider files systematically, but were updating files only in response 

to returned mail or changes submitted by the provider. A 1999 OIG report estimated that 39 

percent of Provider Identification Numbers were still listed as active in the UPIN Registry 

despite the fact that those practice settings had no claims activity for 12 consecutive months. In 

addition, data collection experiences during two 1999 OIG inspections on provider readiness for 

the year 2000 raised questions about the accuracy of address data contained in the UPIN 

Registry. In the first study, 14 percent of physician surveys were returned as undeliverable, 

while 17 percent of physician surveys were returned due to inaccurate addresses during the 

second study. A listing of these report titles and numbers is presented in Attachment 1. 

1 Health Insurance Portability and Accountability Act of 1996, sec. 262, 1173(b) (1996). 

2 Centers for Medicare & Medicaid Services, formerly known as the Health Care Financing Administration, “National Provider 

Identifier Frequently Asked Questions,” 24 February 1999, <http://www.hcfa.gov/stats/npi/faq3-99.htm> (13 March 2001). 
Page 3 - Thomas Scully 

METHODOLOGY 

We selected a sample of 1998 claims as part of a recent inspection to assess the appropriateness 

of Medicare Part B payments for mental health services provided in practitioners’ offices, 

community mental health centers, beneficiaries’ homes, and custodial care facilities. We 

collected mental health records from Medicare providers in support of sample services and 

forwarded these records to an independent contractor for medical review. 

Sample Selection. The stratified random sample of 650 claims was selected from a 1 percent 

file of paid 1998 Part B claims for nine mental health service codes provided in four outpatient 

places of service. This 1 percent file was created from CMS’ 1998 National Claims History file, 

which was 98 percent complete at the time of sample selection. After eliminating 8 claims for 

providers under review by the Office of Investigations, our working sample consisted of 

642 claims representing 571 individual providers. 

Sample Claims and UPIN Registry. We accessed a CMS data file extracted from the UPIN 

Registry to obtain a full name and mailing address for each provider who billed for sample 

mental health services. A provider may have more than one practice setting. Therefore, in 

order to identify the most current address for each provider, we sorted Registry data and selected 

the most recently changed or added practice setting for each UPIN. We then matched sample 

claims to these practice settings using the UPIN and PIN. We obtained mailing addresses for 

561 of the 571 providers in the study sample using the UPIN Registry database. We contacted 

Medicare carriers to obtain mailing addresses for the remaining 10 providers, as we were unable 

to match sample claims to address data in the UPIN Registry. 

Documentation Request. Using these addresses, we mailed written requests for beneficiaries’ 

medical records to the 571 providers of sample mental health services. Documentation requests 

were sent via Federal Express, except those for providers with post office box addresses. When 

mailings were returned to us as undeliverable, we took steps to find alternative provider 

addresses. For the first 23 returned mailings, we accessed Internet sites including the American 

Medical Association’s Physician Select and WebMD to locate alternative provider addresses. 

However, when the volume of returns continued to grow, we contacted individual carriers to 

obtain alternative addresses for an additional 136 providers. We collected medical records from 

Medicare providers from February 2000 to June 2000. 

FINDINGS 

Addresses listed in the UPIN Registry database were inaccurate for 28 percent of 

providers 

Documentation requests mailed to 159 of 561 providers for whom we obtained mailing 

addresses from the UPIN Registry were returned as undeliverable due to inaccurate addresses. 

Examples of inaccurate addresses included street addresses without company names or suite 

numbers, and cases where providers had moved from or were unknown to persons at the mailing 
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address. Inaccurate provider addresses were not limited to a small number of Medicare carriers. 

In fact, claims for providers with inaccurate addresses were billed to and paid by 37 of 62 

separate carrier numbers. Four of these carriers accounted for 36 percent of the 159 providers 

with inaccurate addresses. 

Carriers did not always have accurate addresses for these providers 

We contacted Medicare carriers to obtain alternative addresses for 136 providers whose initial 

mailings were returned as undeliverable. For 23 providers, carriers were not able to provide 

alternative addresses because they had the same inaccurate addresses on file that we used for 

mailing our initial documentation requests. Carriers were able to furnish alternative addresses 

for 113 providers. We sent documentation requests to all new provider addresses. However, 

mailings to 18 of the 113 alternative provider addresses supplied by Medicare carriers were 

returned as undeliverable. 

During our data collection period, we never received medical records for 50 services in the 

mental health study sample due to inaccurate addresses for 41 providers. Based on this data, we 

estimate that Medicare paid about $35 million (± $17 million) in 1998 for outpatient mental 

health services billed by providers with inaccurate mailing addresses. 

RECOMMENDATION 

Along with previous OIG reports that identified problems with the completeness and accuracy 

of provider data contained in carriers’ files and the UPIN Registry, this memorandum provides 

additional evidence that Medicare practitioner enrollment information contained in the UPIN 

Registry is not entirely accurate. Therefore, we recommend that CMS take steps to validate and 

update UPIN Registry data. 

AGENCY COMMENTS 

The CMS concurred with our recommendation and stated that, since the OIG review was 

conducted, it has taken steps to validate and update UPIN Registry data. The CMS noted that it 

has worked with the Medicare contractors and an additional contractor to improve the accuracy 

of data in the UPIN Registry, and has reduced their returned-mail rate to 5 percent. The CMS 

listed a number of factors that it believes may account for the “high volume of mail returns” in 

our study. The CMS also noted that it has not yet determined whether provider data already 

housed in the UPIN Registry will be loaded into the new National Provider System, or whether 

all providers will be required to apply for a National Provider Identifier. The full text of CMS’ 

comments is presented in Attachment 2. 
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OIG RESPONSE 

We support CMS’ current and future efforts to improve the accuracy and validity of provider 

data contained in the UPIN Registry. These efforts are important whether or not CMS decides 

to use UPIN Registry data to populate the National Provider System when it is implemented. 

We also believe that the methods we used to select provider addresses and conduct our data 

collection mailing were sound, and provided a firm basis for our finding that UPIN Registry 

addresses for 28 percent of sample providers were inaccurate. 

The CMS suggested that the provider addresses we selected from the UPIN Registry for our 

mailing may have been inactive addresses. In February 2000, we selected addresses for sample 

providers from a UPIN Registry file that contained only active practice setting addresses. This 

source file was current as of January 2000. We recently reviewed UPIN Registry files 

containing both active and inactive practice setting addresses current as of May 2001. Only 

3 percent (5 of 159) of the provider addresses we found to be inaccurate are currently listed as 

inactive practice setting addresses that appear to have been deactivated just prior to our data 

collection period. In addition, our review indicates that almost 70 percent (110 of 159) of the 

provider addresses we found to be inaccurate in the spring of 2000 are still listed as active 

practice setting addresses in the UPIN Registry. 

The CMS believes that another reason for the high volume of mail returns in our study may be 

that, unlike the post office, Federal Express does not forward mail. We believe that our use of 

an express mail service provided a more reliable gauge of the validity of provider addresses than 

the use of standard mail service. If our letters had been forwarded to sample providers by the 

post office, we would never have known that the addresses we selected from the UPIN Registry 

were inaccurate. 

The CMS also questioned our use of business addresses and group practice addresses to contact 

providers rather than billing addresses, suggesting that this may also have contributed to the 

high rate of mail returns. The UPIN Registry file from which we selected provider addresses 

contains practice location addresses for solo practitioners and members of group practices, but 

does not contain providers’ billing addresses. Providers see patients at these practice location 

addresses, and we believe that these should be addresses where providers can be contacted. 

The CMS also suggested that we may have incorrectly matched provider identification numbers 

to UPIN Registry address data due to the “computer software used in the study.” In the 

methodology section of this report, we describe the process by which we identified and matched 

provider addresses from the UPIN Registry to standard provider identification numbers on 

sample claims. We believe there were no incorrect matches due to computer software error. 

Attachments 
Attachment 1 

OIG Reports Cited in Memorandum 

Carrier Assignment of Medicare Provider Numbers, OEI-06-89-00871 

Carrier Maintenance of Medicare Provider Numbers, OEI-06-89-00870 

Accuracy of Unique Physician Identification Number Data, OEI-07-98-00410 

Y2K Readiness of Medicare Providers, OEI-03-98-00250 

Y2K Readiness of Medicare Fee for Service Providers as of July 1999, OEI-03-98-00253 
Attachment 2 

Centers for Medicare & Medicaid Services’ Comments 
Attachment 2