Department of Health and Human Services 

OFFICE OF 

INSPECTOR GENERAL 

JUNE 2001 

OEI-03-00-00091 

Duplicate Medicare Payments 

by Individual Carriers 
OFFICE OF INSPECTOR GENERAL 

The mission of the Office of Inspector General (OIG), as mandated by Public Law 95-452, is to 

protect the integrity of the Department of Health and Human Services programs as well as the 

health and welfare of beneficiaries served by them. This statutory mission is carried out through 

a nationwide program of audits, investigations, inspections, sanctions, and fraud alerts. The 

Inspector General informs the Secretary of program and management problems and recommends 

legislative, regulatory, and operational approaches to correct them. 

Office of Evaluation and Inspections 

The Office of Evaluation and Inspections (OEI) is one of several components of the Office of 

Inspector General. It conducts short-term management and program evaluations (called 

inspections) that focus on issues of concern to the Department, the Congress, and the public. 

The inspection reports provide findings and recommendations on the efficiency, vulnerability, 

and effectiveness of departmental programs. 

OEI's Philadelphia Regional Office prepared this report under the direction of Robert A. Vito, 

Regional Inspector General, and Linda M. Ragone, Deputy Regional Inspector General. 

Principal OEI staff included: 

REGION HEADQUARTERS 

Robert Katz, Project Leader Tricia Davis, Program Specialist 

Erika Q. Lang, Program Analyst 

To obtain copies of this report, please call the Philadelphia Regional Office at (800) 531-9562. 

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

http://www.hhs.gov/oig/oei 
EXECUTIVE SUMMARY 

PURPOSE 

To determine if individual carriers made duplicate payments for the same Medicare 

Part B services. 

BACKGROUND 

The Health Care Financing Administration (HCFA) contracts with private health 

insurance companies called carriers to process Medicare Part B claims. After furnishing 

a service, providers submit a claim for reimbursement to the carrier with jurisdiction over 

the service. The carrier initially processes the claim, then sends it to one of nine 

Common Working File host sites for approval. Both the carriers and the Common 

Working File host sites review incoming claims for possible duplication using certain 

criteria, such as the dates of service, provider identification number, procedure code, and 

place of service. If a claim is found to be identical to another based on these criteria, it 

should be denied. 

For this inspection, we reviewed potential duplicate services from HCFA’s 5 percent 

National Claims History file for 1998. Our analysis focused on 15 procedure codes that 

should never or rarely be billed more than once a day, and that were the subject of a 

previous Office of Inspector General study about duplicate payments made by more than 

one carrier. In this study, we examined potential duplicate services which were 

submitted for reimbursement to and paid by the same carrier. We also expanded our 

review to include all other procedure codes. 

FINDINGS 

Medicare carriers made potential duplicate payments in 1998 

For the 15 procedure codes that should never or rarely be billed more than once per day, 

individual carriers made potential duplicate payments involving 3,152 services in 1998. 

Questionable allowances for the 15 codes totaled an estimated $2.25 million. Individual 

carriers made an estimated $2.2 million in potential duplicate payments for an additional 

55 evaluation and management codes that should never or rarely be billed more than once 

per day. We also estimated that Medicare made $89 million in potential duplicate 

payments for 2,000 other procedure codes. However, for this latter group, it is possible 

that some of the duplicate services for these codes were appropriately billed, as we did 

not investigate their validity. 

Duplicate Medicare Payments by Individual Carriers iii OEI-03-00-00091 
One carrier paid for more than one-third of the potential duplicate services 

One carrier accounted for 37 percent of duplicate services for the first 15 procedure codes 

we analyzed, more than four times the number for the next highest carrier. Almost all 

carriers in 1998 made duplicate payments for the 15 procedure codes. 

Carrier and Common Working File edits did not prevent potential duplicate 

payments 

Carrier edits should have identified and denied 40 percent of the duplicate services for 

the 15 procedure codes. Eight percent of the duplicate services should have been denied 

based on Common Working File edits. 

RECOMMENDATIONS 

This inspection, combined with our previous inspection report (OEI-03-00-00090) on duplicate 

payments by more than one carrier, establishes that some claims for potential duplicate services 

are not being detected by Medicare carriers and the program’s Common Working File systems. 

To address the vulnerabilities identified in this report, we recommend that HCFA: 

<	 investigate Medicare’s claims processing systems to determine why potential 

duplicate services were not detected. Payments should be recovered for those 

services determined to be inappropriate. 

<	 implement corrective edits or related measures within carrier and Common 

Working File claims processing systems to detect and prevent payments for 

duplicate services billed to the same carrier. If these measures are determined not 

to be cost effective, then conduct additional post-payment reviews, particularly for 

those carriers in which high numbers of duplicate payments were detected. 

We have forwarded claims information to HCFA so they may take appropriate action regarding 

the possible duplicate payments cited in this report. 

AGENCY COMMENTS 

The HCFA concurred with our recommendations. In response to our first 

recommendation, the HCFA stated that they will continue to assess existing duplicate 

payment edits in the Common Working File as well as the Medicare Part B standard 

claims processing systems. The HCFA also plans to reexamine existing edits involved 

with preventing payments for duplicate services in individual carrier systems. Part of this 

examination will include an assessment of those carriers in which a high number of 

Duplicate Medicare Payments by Individual Carriers iv OEI-03-00-00091 
duplicate payments were detected. Upon release of this report, HCFA will proceed with 

recovery actions involving the duplicate payments identified. In response to our second 

recommendation, the HCFA has established a workgroup to analyze potential 

vulnerabilities in existing systems edits. Based upon the workgroup’s findings, HCFA 

will determine appropriate corrective actions to reduce duplicate payments within the 

same carrier. Further, HCFA will consider tasking a program safeguard contractor to 

conduct analysis, identify past instances of duplicate billings within the same carrier, and 

initiate any overpayment recoveries. 

Duplicate Medicare Payments by Individual Carriers v OEI-03-00-00091 
TABLE OF CONTENTS 

PAGE

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

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

FINDINGS

Potential duplicate payments made in 1998 ................................... 4

One carrier responsible for one-third of potential duplicate services ................ 5

Claims processing edits unable to prevent potential duplicate payments ............. 6

RECOMMENDATIONS ................................................ 8

APPENDICES

A: Description of 15 Procedure Codes ....................................... 9

B: Description of 55 Evaluation and Management Codes ........................ 10

C: Estimates and Confidence Intervals ...................................... 12

D. Agency Comments ................................................... 13

Duplicate Medicare Payments by Individual Carriers vi OEI-03-00-00091 
INTRODUCTION 

PURPOSE 

To determine if individual carriers made duplicate payments for the same Medicare 

Part B services. 

BACKGROUND 

During the course of a previous inspection entitled “Medicare Payments for the Same 

Service by More Than One Carrier,” (OEI-03-00-00090), we found evidence that not 

only multiple carriers, but the same carriers, were paying for potential duplicate services. 

Accordingly, we decided to conduct a separate review related to this issue. This 

inspection report is a product of that review. 

Processing Part B Claims 

The Health Care Financing Administration (HCFA), which administers the Medicare 

program, contracts with private health insurance companies called carriers to process 

most Part B claims for payment. Claims under Medicare Part B include medical and 

surgical services by physicians, ambulance services, outpatient hospital services, and 

laboratory services. 

After Part B services are furnished to a Medicare beneficiary, the provider submits a 

claim for reimbursement to the appropriate Medicare carrier. The carrier enters the claim 

into its processing system, calculates the payment amount, and conducts consistency and 

utilization checks using computerized edits. The carrier then sends the claim to one of 

nine host sites of the Common Working File system. The HCFA established the 

Common Working File system in 1991 to improve the accuracy of claims processing. 

The host sites maintain beneficiary claims history and entitlement information. Each 

beneficiary is assigned to only one host site. At the host site, the claim is screened for 

consistency, entitlement, and duplication of previously processed claims. Within 24 

hours of receiving a claim, the host site makes one of three payment determinations: (1) 

pay the claim, (2) reject the claim, or (3) hold the claim to obtain missing information. 

Detecting Duplicate Payments 

As part of Medicare’s guidelines to detect and prevent inappropriate payments, both the 

carriers and the Common Working File system conduct checks on claims to detect 

duplicate payments. According to procedures described in the Medicare Carriers Manual 

Duplicate Medicare Payments by Individual Carriers 1 OEI-03-00-00091 
regarding the control of potential duplicate payments, as well as information obtained 

from HCFA, carriers automatically disallow claims for duplicate services that match on 

the following fields: start and end dates of service, the beneficiary’s health insurance 

claim number, provider identification number, type of service, procedure code, place of 

service, and submitted charge. As a further check for duplicate services, service dates are 

matched with one or more of the following variables: provider identification number, 

type of service, and procedure code. If these items match, the claim is held for review 

and duplicate payments are denied. Line items within claims are also compared for 

duplicate entries. The Common Working File host sites check for duplicate claims by 

comparing the carrier number, the claim’s document control number, and service dates 

on the Common Working File history record. If these fields are identical on two claims, 

one claim is denied. 

METHODOLOGY 

For our previous inspection “Medicare Payments for the Same Service by More Than 

Once Carrier” (OEI-03-00-00090), we examined 1998 Part B paid services for a 5 

percent sample of Medicare beneficiaries in HCFA’s National Claims History file. We 

used six criteria to determine if two services appeared to be duplicate: the beneficiary’s 

health insurance claim number; the unique physician identification number of the 

provider performing the service; the start date of service; HCFA’s Common Procedure 

Coding System code describing the service; and the two modifiers that can further 

describe the service. If the six criteria for two services were identical, we considered 

those services to be potential duplicates. We then identified a universe of services that 

had been billed to more than one carrier from this pool of potentially duplicate services. 

The medical staff of a carrier assisted us in selecting 15 codes that either should only be 

billed once per day by a single provider or that should rarely be billed more than once per 

day. A description of the 15 procedure codes is provided in Appendix A. From these 15 

codes, we selected a random sample of 242 potential duplicate services paid by more than 

one carrier. We contacted the 86 providers who performed the sample services and 

requested medical documentation to justify the billings. None of the documentation 

received justified billings to more than one carrier. 

Data Collection and Analysis 

For the current inspection, we focused our analysis on services for the 15 procedure 

codes used in the previous inspection, since these codes should never or rarely be billed 

more than once a day. From the 1998 National Claims History 5 percent file, we 

identified all services for the 15 codes using the same six criteria described above, but 

that were paid by the same carrier. Since the documentation obtained in the earlier study 

did not justify more than one payment for any of the duplicate services, we did not ask 

providers to send medical documentation for this review. 

Duplicate Medicare Payments by Individual Carriers 2 OEI-03-00-00091 
We later expanded our review to include additional evaluation and management codes. 

According to a carrier’s medical review staff, 55 of 58 evaluation and management codes 

identified as having potential duplicate services should never or rarely be billed more 

than once a day. These 55 codes exclude evaluation and management services contained 

in the 15 procedure codes cited above. We identified all potential duplicate services paid 

by the same carrier for the 55 codes using the same six criteria defined earlier. We did 

not contact the providers of these services for documentation or further clarification of 

their billings. A description of the 55 evaluation and management codes is provided in 

Appendix B. 

In order to illustrate the possible scope of potential duplicate services paid by individual 

Part B carriers, we analyzed the duplicate services for all procedure codes, excluding the 

70 codes mentioned above. Using the six criteria referred to above, we identified 

potentially duplicate services for approximately 2,000 procedure codes. For these codes, 

we neither asked providers for supporting medical documentation nor asked a carrier’s 

medical staff to review these services. 

Based on the results of the previous inspection, we presumed that, within a set of 

duplicate services, one service was appropriate and the related duplicate service(s) was 

not. For monetary calculations, we determined questionable payments from the 

service(s) with the lowest allowed amounts. 

For the potential duplicate services, we identified the carriers that were responsible for 

making the payments. We also applied the edit criteria used by carriers and the Common 

Working File system to determine if the potential duplicate services we identified should 

have been detected by Medicare’s claims processing systems. 

With respect to the 15 original procedure codes and 55 evaluation and management codes 

referred to above, it is unlikely that duplicate services for many of these codes were 

appropriately billed, in view of the results of our previous inspection and the advice of a 

carrier’s medical review staff which indicated these services should never or rarely be 

billed more than once a day. However, we are less certain about the potentially duplicate 

services involving the other 2,000 codes, as we neither analyzed these codes in the earlier 

report nor checked their appropriateness with a carrier’s medical review staff. In the 

final analysis, each duplicate service will have to be investigated to determine its validity. 

__________ 

This study was conducted in accordance with the Quality Standards for Inspections 

issued by the President’s Council on Integrity and Efficiency. 

Duplicate Medicare Payments by Individual Carriers 3 OEI-03-00-00091 
FINDINGS 

Medicare carriers made potential duplicate payments in 1998 

Medicare allowed an estimated $2.25 million in potential duplicate payments for 

15 codes 

In our sample, individual carriers made duplicate payments involving 3,152 services for 

15 procedure codes. These codes should never or rarely be billed more than once per 

day. Using the lowest allowed amounts for each duplicate service, questionable 

allowances equaled approximately $112,000. Based on this, we estimate that Medicare 

made a total of $2.25 million in duplicate payments for the 15 codes in 1998. See 

Appendix C for estimates and confidence intervals. 

As shown in Table 1, questionable allowances for each code ranged from approximately 

$800 for spinal canal magnetic resonance imaging (72158) to more than $28,000 for 

subsequent hospital care per day (99232). 

Table 1. Questionable Allowances and Services Involving Duplication for 15 Codes 

Procedure Code Amount of Questionable Allowances Number of Services Involving Duplication 

99232 $28,119.80 719 

99213 $26,849.81 1,439 

66984 $14,304.78 77 

90921 $7,893.87 75 

99254 $5,735.81 95 

99223 $5,646.48 83 

70553 $4,956.45 38 

90862 $3,516.41 179 

99238 $3,120.49 103 

90801 $2,971.26 52 

99204 $2,546.38 62 

99244 $2,508.24 54 

11721 $2,319.00 124 

90816 $1,193.52 50 

72158 $818.88 2 

TOTAL $112,501.18 3,152 

Source: 1998 National Claims History 5 percent file 

The duplicate services for the 15 procedure codes consisted of services that, according to 

claims data in the 5 percent claims file, were billed to and paid by the same carrier at 

least twice. We found examples in which a carrier paid for the same service more than 

two times. For example, we found 22 different instances in which a carrier paid for the 

same service three times. One carrier paid a physician for six subsequent hospital visits 

Duplicate Medicare Payments by Individual Carriers 4 OEI-03-00-00091 
on the same day for the same beneficiary. Another carrier paid a provider ten times for 

the debridement of six or more nails for one beneficiary on the same day. 

Medicare allowed an estimated $2.2 million in potential duplicate payments for 55 

evaluation and management codes 

We reviewed an additional 58 evaluation and management codes that had potential 

duplicate services in 1998. Of these 58 codes, a carrier’s medical staff stated that 55 

should never or rarely be billed more than once per day. We estimate that Medicare 

made an additional $2.2 million in duplicate payments for these 55 evaluation and 

management codes in 1998. The 55 procedure codes include services such as subsequent 

nursing facility care per day (99312), critical care evaluation and management--first hour 

(99291), and follow-up inpatient consultation for an established patient (99262). 

Potential duplicate payments were found for other procedure codes 

In order to illustrate the possible extent of potential duplicate services paid by individual 

Part B carriers, we also identified duplicate services for all procedure codes besides the 

70 codes mentioned previously. We estimate that Medicare made $89 million in 

potential duplicate payments for these procedure codes. 

The potential duplicate payments comprised nearly 2,000 procedure codes. The types of 

services represented by the codes that occurred most frequently included laboratory and 

pathology tests, vascular diagnostic tests, physical medicine and rehabilitative services, 

and ambulance services. It is possible that some of the duplicate services that we 

identified may have been appropriately billed, as we did not investigate their validity. 

However, the definitions for certain services suggest a provider would never or rarely 

furnish a beneficiary with more than one of these services on the same day. For example, 

procedure code 90925 is defined as end stage renal disease related services per day. 

One carrier paid for more than one-third of the potential

duplicate services 

One carrier accounted for 37 percent of the duplicate services for the 15 procedure codes 

in 1998. However, this carrier accounted for only 4 percent of all Part B services in 

1998. This carrier paid for 1,180 of the 3,152 duplicate services, more than four times 

the number for the next highest carrier (253). Almost all carriers (92 percent) made 

payments for duplicate services involving the 15 procedure codes in 1998. Seventeen 

carriers paid for more than 50 potentially duplicate services for the 15 procedure codes, 

while 5 carriers made only 2 duplicate payments. Table 2 shows the five carriers with 

the highest number of duplicate services involving the 15 procedure codes. 

Duplicate Medicare Payments by Individual Carriers 5 OEI-03-00-00091 
Table 2. Number of Services Involving Duplication for Top Five Carriers 

Carrier Number of Services Involving

Duplication for 15 Procedure Codes 

Percent of 

Total Duplicate Services 

1 1,180 37% 

2 253 8% 

3 129 4% 

4 128 4% 

5 97 3% 

Source: 1998 National Claims History 5 percent file 

The carrier accounting for 37 percent of the duplicate services for the 15 procedure codes 

in 1998 also had the highest number of potential duplicate services involving the 55 

additional evaluation and management codes reviewed. This carrier paid for one-third of 

the services for these evaluation and management codes. 

Carrier and Common Working File edits did not prevent

potential duplicate payments 

Carrier edits 

Forty percent of the duplicate services for the 15 procedure codes should have been 

disallowed, based on carrier edits. At the carrier level, claims for duplicate services that 

match on the following eight fields are disallowed: start and end dates of service, 

beneficiary’s health insurance claim number, provider identification number, type of 

service, procedure code, place of service, and submitted charge. In examining these eight 

fields for the selected duplicate services, we found that they were identical for 40 percent 

of the duplicate services. According to the Medicare Carriers Manual, these duplicate 

services should have been disallowed without clerical intervention. 

Of the remaining duplicate services for which the eight fields were not identical, 79 

percent had non-matching provider identification numbers. While providers have only 

one unique physician identification number, they may have more than one provider 

identification number, which is a billing number assigned by carriers to designate 

separate practice locations or accounting designations. Carrier computer edits cannot 

detect duplicate services if the provider identification numbers are different. Therefore, 

the non-matching provider identification numbers may have allowed these duplicate 

payments to go undetected. 

Common Working File edits 

Eight percent of the duplicate services for the 15 procedure codes should have been 

denied, based on Common Working File edits. At the host sites, if four fields — the 

carrier number, the claim’s document control number, and the start and end dates of 

Duplicate Medicare Payments by Individual Carriers 6 OEI-03-00-00091 
service — on two claims are identical, one claim should be denied. In examining these 

four fields for our selected duplicate services, we found that they were identical for 8 

percent of the duplicate services. 

Of the remaining duplicate services for which the four fields were not identical, almost 

all had non-matching document control numbers. A unique document control number is 

assigned by the carrier to each claim that a provider submits. The Common Working File 

edit is designed to detect duplicate services based, in part, on comparing the document 

control numbers. The high percentage of duplicate services with different document 

control numbers may explain how they evaded detection at the Common Working File 

level. 

Duplicate Medicare Payments by Individual Carriers 7 OEI-03-00-00091 
RECOMMENDATIONS 

This inspection, combined with our previous inspection report (OEI-03-00-00090) on duplicate 

payments by more than one carrier, establishes that some claims for potential duplicate services 

are not being detected by Medicare carriers and the program’s Common Working File systems. 

To address the vulnerabilities identified in this report, we recommend that HCFA: 

<	 investigate Medicare’s claims processing systems to determine why potential 

duplicate services were not detected. Payments should be recovered for those 

services determined to be inappropriate. 

<	 implement corrective edits or related measures within carrier and Common 

Working File claims processing systems to detect and prevent payments for 

duplicate services billed to the same carrier. If these measures are determined not 

to be cost effective, then conduct additional post-payment reviews, particularly for 

those carriers in which high numbers of duplicate payments were detected. 

We have forwarded claims information to HCFA so they may take appropriate action regarding 

the possible duplicate payments cited in this report. 

AGENCY COMMENTS 

The HCFA concurred with our recommendations. In response to our first 

recommendation, the HCFA stated that they will continue to assess existing duplicate 

payment edits in the Common Working File as well as the Medicare Part B standard 

claims processing systems. The HCFA also plans to reexamine existing edits involved 

with preventing payments for duplicate services in individual carrier systems. Part of this 

examination will include an assessment of those carriers in which a high number of 

duplicate payments were detected. Upon release of this report, HCFA will proceed with 

recovery actions involving the duplicate payments identified. In response to our second 

recommendation, the HCFA has established a workgroup to analyze potential 

vulnerabilities in existing systems edits. Based upon the workgroup’s findings, HCFA 

will determine appropriate corrective actions to reduce duplicate payments within the 

same carrier. Further, HCFA will consider tasking a program safeguard contractor to 

conduct analysis, identify past instances of duplicate billings within the same carrier, and 

initiate any overpayment recoveries. 

Duplicate Medicare Payments by Individual Carriers 8 OEI-03-00-00091 
APPENDIX A 

Description of 15 Procedure Codes 

The following is a list of the 15 procedure codes selected for our primary analysis, as well as a 

description of the codes. 

Procedure Code Description of Code* 

11721 Debridement of six or more nails by any method 

66984 Extracapsular cataract removal with insertion of intraocular lens prostheses 

70553 Brain magnetic resonance imaging without contrast material 

72158 Magnetic resonance imaging, spinal canal and contents, without contrast material, lumbar 

90801 Psychiatric diagnostic interview examination 

90816 Individual psychotherapy, 20-30 minutes, inpatient setting 

90862 Pharmacologic management 

90921 End stage renal disease related services per full month, for patients 20 years of age or older 

99204 Office or other outpatient visit for evaluation and management of new patient 

99213 Office or other outpatient visit for evaluation and management of established patient 

99223 Initial hospital care, per day, for evaluation and management of patient 

99232 Subsequent hospital care, per day, for evaluation and management of patient 

99238 Hospital discharge day management, 30 minutes or less 

99244 Office consultation for new or established patient 

99254 Initial inpatient consultation for new or established patient 

* Source: 1998 Physician’s Current Procedural Terminology 

Duplicate Medicare Payments by Individual Carriers 9 OEI-03-00-00091 
APPENDIX B 

Description of 55 Evaluation and Management Codes 

The following is a list of the 55 evaluation and management codes selected for analysis, as well 

as a description of the codes. 

Procedure Code Description of Code* 

99201 Office or other outpatient visit, new patient 

99202 Office or other outpatient visit, new patient 

99203 Office or other outpatient visit, new patient 

99205 Office or other outpatient visit, new patient 

99211 Office or other outpatient visit, established patient 

99212 Office or other outpatient visit, established patient 

99214 Office or other outpatient visit, established patient 

99215 Office or other outpatient visit, established patient 

99217 Observation care discharge day management 

99219 Initial observation care, per day 

99220 Initial observation care, per day 

99221 Initial hospital care, per day 

99222 Initial hospital care, per day 

99231 Subsequent hospital care, per day 

99233 Subsequent hospital care, per day 

99235 Observation or inpatient hospital care 

99236 Observation or inpatient hospital care 

99239 Hospital discharge day management, more than 30 minutes 

99241 Office consultation, new or established patient 

99242 Office consultation, new or established patient 

99243 Office consultation, new or established patient 

99245 Office consultation, new or established patient 

99251 Initial inpatient consultation, new or established patient 

99252 Initial inpatient consultation, new or established patient 

99253 Initial inpatient consultation, new or established patient 

99255 Initial inpatient consultation, new or established patient 

Duplicate Medicare Payments by Individual Carriers 10 OEI-03-00-00091 
APPENDIX B 

Description of 55 Evaluation and Management Codes (cont.)

Procedure Code Description of Code* 

99261 Follow-up inpatient consultation, established patient 

99262 Follow-up inpatient consultation, established patient 

99263 Follow-up inpatient consultation, established patient 

99274 Confirmatory consultation, new or established patient 

99275 Confirmatory consultation, new or established patient 

99281 Emergency department visit 

99282 Emergency department visit 

99283 Emergency department visit 

99284 Emergency department visit 

99285 Emergency department visit 

99291 Critical care evaluation and management, first hour 

99301 Nursing facility assessment, new or established patient 

99302 Nursing facility assessment, new or established patient 

99303 Nursing facility assessment, new or established patient 

99311 Subsequent nursing facility care, per day 

99312 Subsequent nursing facility care, per day 

99313 Subsequent nursing facility care, per day 

99315 Nursing facility discharge day management, 30 minutes or less 

99332 Rest home visit, established patient 

99341 Home visit, new patient 

99342 Home visit, new patient 

99343 Home visit, new patient 

99347 Home visit, established patient 

99348 Home visit, established patient 

99349 Home visit, established patient 

99350 Home visit, established patient 

99354 Prolonged physician service, office setting, first hour 

99356 Prolonged physician service, inpatient setting, first hour 

99375 Physician care plan oversight services, 30 minutes or more 

* Source: 1998 Physician’s Current Procedural Terminology 

Duplicate Medicare Payments by Individual Carriers 11 OEI-03-00-00091 
APPENDIX C 

Estimates and Confidence Intervals

The tables below contain statistical estimates presented in the findings section of this report. 

The point estimates and corresponding 95 percent confidence intervals, based on a 5 percent 

sample of HCFA’s 1998 National Claims History file, were computed using standard statistical 

formulas for a simple random sample. 

Point Estimate 95% Confidence Interval 

Questionable Medicare Allowances 

for 15 Original Codes $2,250,024 $2,067,454 - $2,432,593 

Point Estimate 95% Confidence Interval 

Questionable Medicare Allowances 

for 55 Evaluation and Management Codes $2,205,158 $2,091,705 - $2,318,610 

Point Estimate 95% Confidence Interval 

Questionable Medicare Allowances for All 

Services Except Ones Involving 15 Original

Codes and 55 Evaluation and Management

Codes (Represents 1,906 Codes) 

$89,658,205 $87,611,633 - $91,704,777 

Duplicate Medicare Payments by Individual Carriers 12 OEI-03-00-00091 
APPENDIX D 

Health Care Financing Administration Comments

Duplicate Medicare Payments by Individual Carriers 13 OEI-03-00-00091 
a APPENDIX D 

Duplicate Medicare Payments by Individual Carriers 14 OEI-03-00-00091 
APPENDIX D 

Duplicate Medicare Payments by Individual Carriers 15 OEI-03-00-00091