Department of Health and Human Services 
OFFICE OF 
INSPECTOR GENERAL 
Common Working File Edits for 
Unauthorized Laboratory Tests 
JANET REHNQUIST 
Inspector General 
JANUARY 2002 
OEI-O5-00-00050  OFFICE OF INSPECTOR GENERAL 
The mission of the Office of Inspector General (OIG) mandated by Public Law 95-452, as 
amended by Public Law 100-504, 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. 
The Office of Evaluation and Inspections Chicago regional office prepared this report under the 
direction of William C. Moran, Regional Inspector General and Natalie Coen, Deputy Regional 
Inspector General.  Principal OEI staff included: 
Region  Headquarters 
John Traczyk, Team Leader  Bambi Straw, Program Specialist

Thomas Komaniecki, Analyst

Susan Otter, Analyst 

To obtain copies of this report, please call the Chicago Regional Office at (312) 353-4124. 
Reports are also available on the World Wide Web at our home page address: 
http://oig.hhs.gov/oei/  E X E C U T I V E  S U M M A R Y  
PURPOSE 
To determine whether laboratory payment safeguards have been effective in protecting 
Medicare program funds. 
BACKGROUND 
This report focuses on how well the Common Working File (CWF) edits work when 
processing claims from laboratories holding a CLIA Certificate of Waiver or Certificate 
for Provider Performed Microscopy Procedures.  The CWF scrutinizes claims to ensure 
that the laboratory services billed are authorized under a providers CLIA certificate. We 
did not analyze claims submitted by laboratories certified by CLIA to do moderate or high 
complexity laboratory testing.  These laboratories hold CLIA Certificates of Compliance 
or Accreditation and the services they bill to Medicare are not yet subject to CWF edits. 
FINDINGS 
Claim Processing Edits Appear Effective at Detecting And Denying 
Payment For Services Not Authorized by a Laboratorys CLIA 
Certificate of Waiver or Certificate For Provider Performed Microscopy 
Procedures 
Only 98 of the 26,456 laboratories (less than 1 percent) in our sample managed to elude 
CMSs Common Working File claims processing edits and were paid for services not 
authorized by their CLIA certificate.  Based on our sample, it appears that CMSs 
Common Working File edits were effective and resulted in the correct processing (denial 
or payment) of nearly all (998 of every 1,000) services billed by 26,456 laboratories 
holding a Certificate of Waiver or a Certificate for Provider Performed Microscopy 
Procedures. 
Based on our sample, we estimate that, in 1999, about 16,000 laboratory services (out of 
an estimated 8.1 million services submitted) went undetected by CWF edits.  We also 
estimate that these claims accounted for less than $76,000 of the estimated $31.3 million 
paid for services submitted by laboratories holding a Certificate of Waiver or a Certificate 
for Provider Performed Microscopy Procedures. 
CWF Laboratory Edits  i  OEI-05-00-00050  However, Certain CMS Survey and Certification Policies, in Effect in 
1999, Appear to Adversely Affect Common Working File Payment 
Safeguards 
CMS Policy:  Permits laboratories that obtain a CLIA Certificate of Registration to bill 
Medicare before they have been surveyed. 
Fifty laboratories in our sample were holding a CLIA Certificate of Registration when 
Medicare paid them for laboratory services in 1999.  These 50 laboratories gained access 
to Medicare and Medicaid payment systems simply by submitting a CLIA application to 
CMS indicating that they would be doing moderate or high complexity laboratory tests. 
Based on unverified application information, they were given a CLIA Certificate of 
Registration and a CLIA number for use in billing Medicare and Medicaid. 
The CMS policy allowed these 50 laboratories to operate without a visit from CLIA 
surveyors for up to 24 months.  During this period, they were allowed to receive payments 
from Medicare even though they had not paid all of their CLIA fees.  Most of these 
laboratories billed Medicare for less than $1,000 in 1999 and several were paid $10,000 or 
more.  One laboratory was paid nearly $200,000.  The CWF processed these claims 
correctly; however, we question a policy that permits unrestricted access to the Medicare 
payment system before laboratories have paid their survey and certification fees and been 
inspected.  The CMS is aware of this problem and is considering a change in procedure. 
CMS Policy:  Prohibits the downgrading of a CLIA certificate until the current 
certificate has expired. 
Analysis of our 5 percent file revealed that 1,104 laboratories had downgraded their CLIA 
certification sometime during 1999.  Medicare paid for more than 13,600 moderate and 
high complexity services billed by these laboratories in our sample.  These services may 
not have been paid had the CWF received updated information that the laboratory had 
downgraded its CLIA certification. 
When these providers submitted their claims for payment, it was CMS policy not to 
downgrade CLIA certificate information until the existing CLIA certificate had expired. 
Some of the paid services may have been denied if updated CLIA certification information 
had been relayed in a more timely manner to the CWF.  The CMS is considering a policy 
change that would result in more timely updates of laboratory certification information. 
Based on our sample, a change in procedure could affect the processing of an estimated 
275,000 laboratory services. 
CWF Laboratory Edits  ii  OEI-05-00-00050  RECOMMENDATIONS 
It appears that CMSs Common Working File has been effective in ensuring that 
laboratories holding CLIA Certificates of Waiver and Certificates for Provider Performed 
Microscopy Procedures are paid correctly.  Based on the vulnerabilities identified in this 
report, we encourage CMS to exam and revise its operating procedures to: 
<	 Shorten the length of time allowed between application and onsite survey of new 
laboratories. 
<	 Prohibit laboratories from billing Medicare until they have paid all of their CLIA 
fees or been surveyed to ensure compliance with CLIA regulations. 
<	 Downgrade CLIA certificates and transmit the information to the CWF as soon as 
it becomes known that a laboratory will no longer do moderate or high complexity 
testing. 
AGENCY COMMENTS 
We received comments on this report from CMS.  They concur with our all of our 
recommendations and have made changes to their procedures that will help meliorate the 
common working file edit system by addressing the vulnerabilities identified in this report. 
Their comments can be found in Appendix A. 
CWF Laboratory Edits  iii  OEI-05-00-00050  T A B L E  O F  C O N T E N T S  
PAGE 
EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  i 
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

FINDINGS

Laboratory processing edits appear effective  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Survey and certification policy vulnerabilities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

RECOMMENDATIONS  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

APPENDIX A  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10

CWF Laboratory Edits  OEI-05-00-00050  I N T R O D U C T I O N  
PURPOSE 
To determine whether laboratory payment safeguards have been effective in protecting 
Medicare program funds. 
BACKGROUND 
The Centers for Medicare & Medicaid Services 
The Centers for Medicare & Medicaid Services (CMS) administers Medicare, the nation's 
largest health insurance program, which covers approximately 39 million Americans. 
Medicare provides health insurance to people age 65 and over, and to those who have 
permanent kidney failure and to certain people with disabilities.  The CMS also works 
with the States to provide health insurance to another 35 million Americans enrolled in 
Medicaid and the State Children's Health Insurance Program. 
Clinical Laboratory Improvement Amendments of 1988 
In addition to providing health insurance, CMS also performs many quality-focused 
activities, including regulation of clinical laboratory testing.  In 1988, Congress enacted 
the Clinical Laboratory Improvement Amendments (CLIA).  The CLIA established 
quality standards for all laboratory testing to ensure the accuracy, reliability and 
timeliness of patient test results regardless of where the test was performed. 
Under current law, all laboratories must be certified under CLIA to perform testing on 
human specimens.1  Laboratories enroll in the program by completing an application and 
paying a certificate fee to CMS.  Fees are based on certificate type, annual volume and 
number of test specialities. 
Each laboratory must have a certificate appropriate for the complexity of the testing they 
conduct.  All laboratory test methods are classified based on testing complexity into one of 
four categories:  high, moderate, provider-performed microscopy or waived test 
1  The CLIA regulations define a laboratory as a facility for the . . . examination of materials derived from 
the human body for the purpose of providing information for the diagnosis, prevention or treatment of any disease 
or impairment of, or the assessment of the health of, human beings. These examinations also include procedures to 
determine, measure, or otherwise describe the presence or absence of various substances or organisms in the body. 
The regulations allow for some exceptions, including forensic laboratories, research laboratories that do not report 
patient-specific results, drug testing laboratories certified by the Substance Abuse and Mental Health Services 
Administration, and some Federal laboratories. 
CWF Laboratory Edits  1  OEI-05-00-00050  methods.  The type of CLIA certificate a laboratory receives relates to the complexity of 
testing conducted at that laboratorys site.  All laboratories are required to keep CMS 
informed of major changes in testing, ownership or directorship. 
Of the nearly 170,000 laboratory2 sites certified by CLIA as of July 2000, about 86,500 
sites have been issued a Certificate of Waiver.  Approximately 36,000 physicians and other 
approved providers hold Certificates for Provider Performed Microscopy Procedures. 
These laboratories are permitted to perform specific moderate-complexity microscopy 
procedures and waived tests.  The remaining 41,500 laboratories conduct moderate or 
high complexity testing. 
A CLIA surveyor must inspect laboratories that conduct moderate or high complexity 
testing before they can receive CLIA certification.  These onsite inspections occur after 
the laboratory has paid its CLIA fees.  The CMS allows laboratories up to 24 months from 
the date of their application to pay CLIA certification fees.  In the interim, laboratories are 
issued a Certificate of Registration and a CLIA number that allows them to conduct 
testing and bill Medicare and Medicaid until CMS  inspects them.  Once the laboratory has 
proven to surveyors that it meets all CLIA requirements, it is issued a Certificate of 
Compliance or a Certificate of Accreditation.  The certificates expire 24 months after 
issue.  All laboratories must renew their CLIA certificate every 24 months. 
Medicare Payment 
Medicare and Medicaid require CLIA certification as a condition of payment.  Medicare 
has two parts: Hospital Insurance (Part A) and Supplemental Medical Insurance (Part B). 
<<	 Medicare Part A:  Provides coverage of inpatient hospital services, skilled 
nursing facilities, home health services and hospice care.  These providers are 
required to ensure that the laboratory services furnished to the patients in their care 
are performed by CLIA certified laboratories.  Reimbursement for these laboratory 
services is included in Medicares payment to these providers. 
<	 Medicare Part B:  Helps pay for the cost of physician services, outpatient hospital 
services, laboratory services, medical equipment and other health care services and 
supplies.  Providers of these services submit itemized bills for the services they 
provide to Medicare for payment. 
Medicare carriers and intermediaries process claims for payment of laboratory services. 
These fiscal agents ensure that all claims submitted for payment are accurate and 
complete.  Incomplete claims and claims that fail computer system accuracy checks (called 
edits) are rejected.  Claims not rejected by the fiscal agents payment safeguards are 
prepared for payment using the Clinical Laboratory Fee Schedule.  The Clinical 
2  This includes about 5,800 laboratories in New York and Washington which are exempt States. These 
States meet CMS requirements to survey and certify laboratories under their State program. The States must pay a 
fee and show CMS that the State program meets or exceeds the requirements for laboratories under CLIA. 
CWF Laboratory Edits  2  OEI-05-00-00050  Laboratory Fee Schedule determines the amount Medicare will pay for each laboratory 
service billed to the program. 
Payment Safeguards: Claims Processing and Common Working File Edits 
Laboratory claims submitted to Medicare for payment undergo scrutiny by the fiscal agent 
that received the claim and by the Common Working File maintained by CMS.  When 
intermediaries and carriers receive a claim for payment of clinical laboratory services they 
process the claim using the information submitted by the provider and information 
contained in their files.  When they have finished processing the claim to the point of 
payment or denial, they submit the claim to the Common Working File (CWF).  The CWF 
uses its programs and files to decide whether to accept and pay the claim as submitted or 
reject the claim and deny payment. 
The CWF scrutinizes claims for reimbursement of clinical laboratory services to ensure 
that the provider submitting the claim was certified by CLIA when the service was 
provided to the patient.  If the claim is from a laboratory provider holding a CLIA 
Certificate of Waiver or Certificate for Provider-Performed Microscopy, the CWF also 
checks to make sure that the laboratory services billed are authorized under that 
providers CLIA certificate.  Laboratory services not authorized under the providers 
CLIA certificate are denied payment. 
Information about a laboratorys CLIA survey and certification is periodically transmitted 
to the CWF from CMSs Online Survey, Certification and Reporting (OSCAR) system. 
The OSCAR system relies on laboratory surveyors to update survey and certification 
information when it becomes known.  This updated information is then relayed to the 
CWF. 
METHODOLOGY 
We used a claim sample containing all of the claims submitted for 5 percent of Medicare 
beneficiaries in calendar year 1999.  Using this 5 percent sample, we created a file 
containing all of the laboratory services submitted to Medicare for these patients.  We 
sorted this file on the CLIA laboratory number of the provider. 
In April 2000, we obtained data about CLIA certified laboratories from the CLIA Online 
Survey, Certification and Reporting (OSCAR) system.  We used this data to create three 
other files.  One file contained information about laboratories having a CLIA Certificate of 
Waiver.  The second contained information about laboratories holding Certificates for 
Provider Performed Microscopy Procedures.  The third contained information about 
laboratories certified by CLIA to do moderate or high complexity laboratory testing.  We 
sorted these files on the CLIA laboratory number to facilitate the matching of claim 
information with CLIA survey and certification information. 
CWF Laboratory Edits  3  OEI-05-00-00050  Using information from CMSs web site, we created an Access database containing all of 
the waived procedure codes.  A second Access database was created that contained all of 
the procedure codes for provider-performed microscopy.  The provider-performed 
microscopy file also contained all of the waived laboratory procedure codes. 
For our first data run, we used information from the April 2000 CLIA survey and 
certification file containing information about waived laboratories.  We merged this 
information with the 5 percent sample file containing 1999 claim information.  We created 
a program that enabled us to identify and isolate all of the laboratory services billed to 
Medicare by the laboratories holding a CLIA Certificate of Waiver.  Using our Access 
database, we identified authorized and unauthorized services billed to Medicare by 
laboratories holding a CLIA Certificate of Waiver.  We also used our program to 
determine whether CMS paid or denied these services.  This process was repeated for the 
analysis of the services submitted by laboratories holding Provider Performed Microscopy 
Certificates. 
Our sample selection method prevents us from projecting our findings to the universe of 
laboratories.  We selected our laboratories and services from a 5 percent beneficiary file. 
Consequently, projections as to the number of laboratories affected in the universe would 
not be reliable.  Our sample methodology does enable us to make projections about 
services and payments. 
We derived some information in this report from discussions that we had with CMS and 
State agency CLIA surveyors.  These discussions were held during the winter of 
2000/2001 as part of the inspections entitled:  CLIA Regulation of Unestablished 
Laboratory Tests, (OEI-05-00-00250) and Enrollment and Certification Processes in the 
Clinical Laboratory Improvement Amendments Program (OEI-05-00-00251). 
We conducted our review in accordance with the Quality Standards for Inspections issued 
by the Presidents Council on Integrity and Efficiency. 
CWF Laboratory Edits  4  OEI-05-00-00050  F I N D I N G S  
Claim processing edits appear effective at detecting and 
denying payment for services not authorized by a 
laboratorys CLIA Certificate of Waiver or Certificate For 
Provider Performed Microscopy Procedures 
The CMS has done a good job in developing and implementing claims processing edits for 
waived and provider-performed microscopy laboratory services.  The common working 
file edits they have developed appear effective in identifying: 
<  laboratories that attempt to bill Medicare without proper CLIA certification, and 
<	 nearly all laboratory services billed to Medicare but not authorized under a 
providers CLIA certificate. 
Overall, less than 1 percent of the laboratories in our sample managed to elude CMSs 
Common Working File claims processing edits and were paid for services not authorized 
by their CLIA certificate.  Based on our sample, it appears that CMSs Common Working 
File edits were effective and resulted in the correct processing (denial or payment) of 
nearly all (998 of every 1,000) services billed by laboratories holding a Certificate of 
Waiver or a Certificate for Provider Performed Microscopy Procedures. 
Our 5 percent sample of claims submitted in 1999 shows that Medicare allowed just over 
$1.5 million in payments to laboratories holding a Certificate of Waiver or a Certificate for 
Provider Performed Microscopy Procedures.  Of this amount, less than 1 percent appears 
to have been paid incorrectly due to some Common Working File edit failure.  Of the 
nearly 26,000 laboratories in our sample, fewer than 100 by-passed CWF edits and were 
paid incorrectly.  Most of these laboratories were paid for services not covered by their 
CLIA certificate when they used a procedure code modifier with a laboratory service 
procedure code. 
Based on our sample, we estimate that, in 1999, about 16,000 laboratory services (out of 
an estimated 8.1 million services submitted) went undetected by CWF edits.  We also 
estimate that these claims accounted for less than $76,000 of the estimated $31.3 million 
paid for services submitted by laboratories holding a Certificate of Waiver or a Certificate 
for Provider Performed Microscopy Procedures. 
CWF Laboratory Edits  5  OEI-05-00-00050  However, Certain CMS survey and certification policies, in 
effect in 1999, appear to adversely affect common working 
file payment safeguards 
The CWF functioned correctly and CMS correctly paid claims under the policies that 
existed in 1999.  However, the payment decisions made by CMSs Common Working File 
system may have been affected by CLIA survey and certification information used by the 
CWF system.  Two CMS survey and certification policies (in effect during 1999) may 
have affected the way CWF edits handled payment decisions on claims submitted by 1,154 
laboratories in our sample. 
Policy 1:  Permits laboratories that obtain a CLIA Certificate of Registration 
to bill Medicare before they have been surveyed 
Permitting laboratories that obtain a CLIA Certificate of Registration to bill Medicare 
before they have been surveyed may be a vulnerability because it enables laboratories to 
bypass Common Working File payment safeguards. 
The payment decisions made by CMSs Common Working File system may have been 
affected by the quality of CLIA survey and certification information the CWF system 
received from CLIA.  Based on our analysis, payments to 1,154 laboratories (496 waived 
and 659 PPM) may have been affected by survey policy and procedures in effect during 
1999.  Our analysis found that 50 laboratories holding a CLIA Certificate of Registration 
had billed Medicare during 1999 but were never certified to perform moderate or high 
complexity tests; yet, they billed Medicare for these tests. 
These 50 laboratories had submitted a CLIA application to CMS indicating that they 
would be doing moderate or high complexity laboratory tests.  Based on information 
provided on their application, CMS gave these laboratories a CLIA Certificate of 
Registration and a CLIA number.  The CLIA registration certificate enabled these 
laboratories to operate for up to 24 months without verification of the information 
provided on the application.  Information about these laboratories was then provided to 
CMSs CWF system.  The CWF system then used that information in its payment 
decisions. 
These 50 laboratories submitted their claims for payment during a time when CMS policy 
allowed them to operate without a survey for up to 24 months.  They had not paid all of 
their CLIA certification fees.  Laboratory surveyors had not made any visits to the 
laboratory to ensure compliance with CLIA regulatory requirements.  These laboratories 
were given access to the Medicare payment system that enabled them to bypass many 
CWF edits. 
Of the 50 laboratories paid while holding a Certificate of Registration, 45 had not billed 
Medicare extensively for moderate or high complexity tests.  Medicare paid most of these 
laboratories less than $1,000 and several laboratories were paid $10,000 or more.  One 
laboratory was paid nearly $200,000.  The CWF processed these claims correctly under 
CWF Laboratory Edits  6  OEI-05-00-00050  the policy that existed at the time provider submitted the claims.  We have no reason to 
suspect wrong doing by any of these laboratories.  However, we are concerned about the 
potential for an unscrupulous provider to gain unchecked access to the Medicare and 
Medicaid payment systems.  Some State laboratory surveyors have told us that they have 
issued CLIA numbers to laboratories that apparently did not exist.  These laboratories 
used the 24 months they were permitted to operate under a CLIA Certificate of 
Registration to obtain Medicare and Medicaid payments. 
We do not mean to infer that all laboratories that downgrade their applications to a 
Certificate of Waiver or a Certificate for Provider Performed Microscopy Procedures are 
unscrupulous.  Many reasons, including the cost of CLIA certification, inability to meet 
CLIA standards, competition in the marketplace and other factors, could explain why 
laboratories do not follow through and obtain a CLIA Certificate of Compliance or a 
Certificate of Accreditation. 
The CMS is aware of this vulnerability and is considering procedural changes to reduce 
Medicares exposure to unscrupulous providers who would seek to defraud Medicare and 
Medicaid.  Requiring payment of all CLIA certification and survey fees ensures more 
timely onsite visits to laboratories.  Earlier onsite visits will help to ensure that the quality 
of testing done at a laboratory meets CLIA standards before Medicare and Medicaid make 
any substantial payments for substandard or poor laboratory testing.  It will also make it 
more difficult for nonexistent providers to defraud Medicare and Medicaid. 
Policy 2:  Prohibits the downgrading of a CLIA certificate until the current 
certificate has expired 
Untimely changes to a laboratorys CLIA certificate information create a vulnerability that 
may affect Common Working File payment safeguards.  More than 13,600 (out of 18,200 
plus) laboratory services in our sample got through the Common Working File edits 
because they were billed by providers whose CLIA Certificate of Compliance or 
Certificate of Accreditation was still shown as valid in CMS systems.  Our sample 
contained 1,104 providers who changed their laboratory certification from moderate and 
high complexity testing to provider performed microscopy or waived testing at some point 
during 1999. 
During the time period these 1,104 laboratories submitted their claims for payment, CMS 
did not update information about downward changes in a laboratorys CLIA certification 
until the laboratorys higher level CLIA certification had expired.  For example, a 
laboratory issued a Certificate of Compliance effective January 1, 1998 could continue to 
bill for moderate and high complexity testing until January 2000 even if they had notified 
CMS that effective January 2, 1998 they would only be doing waived tests. 
We did not contact the State surveyors to determine exactly when they were notified that 
the laboratory would no longer be doing moderate or high complexity tests.  Some of 
these laboratories may have elected to change their certification when their certificates 
came up for renewal.  Others may have had trouble meeting CLIA certification 
requirements during their re-certification visit.  Some may have sent notice to CMS that 
CWF Laboratory Edits  7  OEI-05-00-00050  they had ceased conducting moderate and high complexity testing before their CLIA 
certificate expired.  Finally changes in a laboratorys certification may not become 
apparent until a laboratory surveyor discovers that moderate and high complexity testing 
had ceased at some earlier point in time and the laboratory failed to notify CMS of the 
change. 
The CMS is considering a new procedure that will result in the Common Working File 
having more accurate and timely information about a laboratorys CLIA certification. 
This change in procedure could help prevent payment of moderate and high complexity 
services billed by laboratory providers whose CLIA certificates are changed to either a 
Certificate of Waiver or a Certificate for Provider Performed Microscopy Procedures. 
Based on our sample, this change could affect the processing of an estimated 275,000 
laboratory services. 
CWF Laboratory Edits  8  OEI-05-00-00050  R E C O M M E N D A T I O N S  
It appears that the CMSs Common Working File has been effective in ensuring that 
providers holding CLIA Certificates of Waiver and Certificates for Provider Performed 
Microscopy Procedures are paid only for tests authorized under their CLIA certificate. 
We believe that the CMS survey and certification policies and procedures discussed in this 
report create vulnerabilities in Medicare claims processing.  Therefore, we encourage 
CMS to examine and revise its operating procedures to: 
<	 Shorten the length of time allowed between application and onsite survey of new 
laboratories. 
<	 Prohibit laboratories from billing Medicare until they have paid all of their CLIA 
fees or been surveyed to ensure compliance with CLIA regulations. 
<	 Downgrade CLIA certificates and transmit the information to the CWF as soon as 
it becomes known that a laboratory will no longer do moderate or high complexity 
testing. 
The first of these three recommendations was also made the the OIG in an earlier report 
entitled, Enrollment and Certification Processes in the Clinical Laboratory Improvement 
Amendments Program. 
AGENCY COMMENTS 
We received comments on this report from CMS.  They concur with our all of our 
recommendations and have made changes to their procedures that will help meliorate the 
common working file edit system by addressing the vulnerabilities identified in this report. 
Their comments can be found in Appendix A. 
CWF Laboratory Edits  9  OEI-05-00-00050  APPENDIX A 
CMS Comments on this Report

CWF Laboratory Edits  10  OEI-05-00-00050  CWF Laboratory Edits  11  OEI-05-00-00050