Department of Health and Human Services 
OFFICE OF 
INSPECTOR GENERAL 
Duplicate Medicare Payments 
by Individual Carriers 
JUNE 2001 
OEI-03-00-00091  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  E X E C U T I V E   S U M M A R Y  
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 HCFAs 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. 
iii
Duplicate Medicare Payments by Individual Carriers   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 programs Common Working File systems. 
To address the vulnerabilities identified in this report, we recommend that HCFA: 
<	 investigate Medicares 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 
iv
Duplicate Medicare Payments by Individual Carriers   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 workgroups 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. 
v
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  T A B L E  O F  C O N T E N T S  
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

vi
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  I N T R O D U C T I O N  
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 Medicares 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 
1
Duplicate Medicare Payments by Individual Carriers   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 beneficiarys 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 claims 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 HCFAs National Claims History file. We 
used six criteria to determine if two services appeared to be duplicate: the beneficiarys 
health insurance claim number; the unique physician identification number of the 
provider performing the service; the start date of service; HCFAs 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. 
2
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  We later expanded our review to include additional evaluation and management codes. 
According to a carriers 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 carriers 
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 Medicares 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 
carriers 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 carriers 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 Presidents Council on Integrity and Efficiency. 
3
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  F I N D I N G S  
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 
4
Duplicate Medicare Payments by Individual Carriers   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 carriers 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. 
5
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  Table 2. Number of Services Involving Duplication for Top Five Carriers 
Carrier  Number of Services Involving Percent of 
Duplication for 15 Procedure Codes  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, 
beneficiarys 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 claims document control number, and the start and end dates of 
6
Duplicate Medicare Payments by Individual Carriers   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. 
7
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  R E C O M M E N D A T I O N S  
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 programs Common Working File systems. 
To address the vulnerabilities identified in this report, we recommend that HCFA: 
<	 investigate Medicares 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 workgroups 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. 
8
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  A P P E N D I X  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 Physicians Current Procedural Terminology 
9
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  A P P E N D I X  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 
10
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  A P P E N D I X  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 Physicians Current Procedural Terminology 
11
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  A P P E N D I X  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 HCFAs 1998 National Claims History file, were computed using standard statistical 
formulas for a simple random sample. 
Point Estimate  95% Confidence Interval 
Questionable Medicare Allowances 
$2,250,024  $2,067,454 - $2,432,593 
for 15 Original Codes 
Point Estimate  95% Confidence Interval 
Questionable Medicare Allowances 
$2,205,158  $2,091,705 - $2,318,610 
for 55 Evaluation and Management Codes 
Point Estimate  95% Confidence Interval 
Questionable Medicare Allowances for All 
Services Except Ones Involving 15 Original
$89,658,205  $87,611,633 - $91,704,777 
Codes and 55 Evaluation and Management
Codes (Represents 1,906 Codes) 
12
Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  A P P E N D I X  D  
Health Care Financing Administration Comments

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Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  A P P E N D I X  D  
a 
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Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091  A P P E N D I X  D  
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Duplicate Medicare Payments by Individual Carriers   OEI-03-00-00091