Department of Health and Human Services
OFFICE OF 
   
INSPECTOR GENERAL 
 
 
 
 
 
 
 
 
MEDICA RE POWER WHEELCHAIR 
 
C F D N
LAIMS  REQUENTLY  ID  OT 
 
 
M D
EET  OCUMENTATION 
 
  R  
EQUIREMENTS
 
 
 
 
Daniel R. Levinson  
Inspector General 
 
December 2009 
OEI-04-07-00401   
Office of Inspector General 
http://oig.hhs.gov 
 
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amended, is to protect the integrity of the Department of Health and Human Services 
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The Office of Counsel to the Inspector General (OCIG) provides general legal services to 
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enforcement authorities.   
   
 E X E C U T I V E   S U M M A R Y  
OBJECTIVE
 
To determine the extent to which standard and complex rehabilitation 
power wheelchair claims met Medicare documentation requirements 
during the first half of calendar year 2007.     
BACKGROUND 
Medicare beneficiaries are eligible to receive power wheelchairs under 
Medicare Part B coverage of durable medical equipment.  Beneficiaries 
receive power wheelchairs from suppliers, which bill the Medicare 
program for reimbursement.   The supplier receives the power 
wheelchair prescription, along with documentation from the 
beneficiarys medical record to support the power wheelchairs necessity, 
from the prescribing physician.  Based on the prescription, the supplier 
recommends a specific power wheelchair for the beneficiary.  The 
physician must then review and approve the suppliers 
recommendation.   
Standard power wheelchairs accounted for nearly three-quarters of 
Medicares power wheelchair claims and expenditures in the first half of 
2007.  These power wheelchairs provide basic, daily mobility.  Complex 
rehabilitation power wheelchairs accounted for less than 7 percent of 
power wheelchair expenditures during the first half of 2007.  To receive 
a complex rehabilitation power wheelchair, the beneficiarys mobility 
limitation must result from a neurological condition, muscle disease, or 
skeletal deformity.  Complex rehabilitation power wheelchairs can be 
upgraded with power options and other electronic features to 
accommodate beneficiaries mobility needs. 
To receive Medicare payment for a power wheelchair, suppliers must 
meet all documentation requirements included in the power wheelchair 
Local Coverage Determinations (LCD).  The power wheelchair LCDs 
published by each of Medicares four Durable Medical Equipment 
Medicare Administrative Contractors are identical.  The LCD requires 
that suppliers maintain a variety of documents that support the 
beneficiarys need for, and the appropriateness of, the provided power 
wheelchair.  Specifically, the supplier must have the power wheelchair 
prescription, supporting documentation from the beneficiarys medical 
record, the specialty evaluation report, the detailed product description, 
the home assessment report, and proof of delivery.  For many of these 
documents, the LCD includes requirements related to the documents 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  i   
   
E X E C U T I V E   S U M M A R Y  
contents and the timeframes within which the supplier should create or 
receive the documents. 
We selected a random sample of 375 claims for standard and complex 
rehabilitation power wheelchairs supplied to Medicare beneficiaries in 
the first half of 2007.  We then collected documents required by 
Medicare from the power wheelchair suppliers, determined the extent to 
which claims met documentation requirements, and projected our 
results nationally. 
FINDINGS 
Three out of five claims for standard and complex rehabilitation 
power wheelchairs did not meet Medicare documentation 
requirements during the first half of 2007.  We found that 60 percent 
of Medicare claims for standard and complex rehabilitation power 
wheelchairs that beneficiaries received in the first half of 2007 did not 
meet one or more documentation requirements.  Power wheelchair 
claims that did not meet all documentation requirements accounted for 
$112 million in improper Medicare payments, out of $189 million total 
allowed by Medicare during the 6-month period.  Beneficiaries were 
responsible for paying $22 million of this amount.  Power wheelchair 
claims were more likely to meet some documentation requirements than 
others.  Error rates ranged from 1 percent of claims for which the 
suppliers did not submit proof of delivery to 40 percent of claims for 
which the supporting documentation and detailed product descriptions 
were not submitted or were incomplete.  Two out of five power 
wheelchair claims had multiple errors.  In addition, suppliers submitted 
incomplete documents almost three times as often as they failed to 
submit required documents.  The specialty evaluation report was one of 
the documents most often not submitted by complex rehabilitation 
power wheelchair suppliers. 
Medicare documentation error rates varied by power wheelchair type 
and supplier volume during the first half of 2007.   Complex 
rehabilitation power wheelchair claims had a higher documentation 
error rate (93 percent) than standard power wheelchair claims                 
(58 percent).  However, because suppliers provided over 13 times more 
standard than complex rehabilitation power wheelchairs, 
documentation errors for standard power wheelchair claims resulted in 
more improper payments than claims for complex rehabilitation power 
wheelchairs ($97 million and $15 million, respectively).  Standard power 
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E X E C U T I V E   S U M M A R Y  
wheelchair claims submitted by low-volume suppliers had a higher 
documentation error rate (72 percent) than those from high-volume 
suppliers (55 percent).  However, claims that high-volume suppliers 
submitted accounted for more improper payments than did claims 
submitted by low-volume suppliers ($77 million and $20 million, 
respectively). 
RECOMMENDATIONS 
Power wheelchair suppliers must maintain specific documentation to 
support beneficiaries need for the provided power wheelchairs.  
Medicare policy requires that suppliers and prescribing physicians 
coordinate to ensure that beneficiaries receive the most appropriate 
equipment to accommodate their mobility needs.   
We found that 60 percent of claims for standard and complex 
rehabilitation power wheelchairs that beneficiaries received in the first 
half of 2007 did not meet all Medicare documentation requirements.  
These claims accounted for $112 million in improper Medicare 
payments, out of the $189 million total allowed by Medicare.  
Beneficiaries were responsible for paying $22 million of this amount.   
We also found that complex rehabilitation power wheelchair claims had 
a higher documentation error rate than standard power wheelchair 
claims.  Standard power wheelchair claims submitted by low-volume 
suppliers had a higher documentation error rate than those from      
high-volume suppliers.   
Based on these findings, we recommend that the Centers for Medicare 
& Medicaid Services (CMS): 
Improve compliance with Medicares power wheelchair 
documentation requirements.  CMS should consider the following 
methods for improving compliance:  
  conduct additional reviews of power wheelchair claims,   
  recover overpayments from suppliers that do not meet 
documentation requirements and consider further action as 
appropriate, and 
  increase education for suppliers and prescribing physicians about 
documentation requirements.   
Take appropriate action on sampled claims found to be in error. 
 
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E X E C U T I V E   S U M M A R Y  
AGENCY COMMENTS AND OFFICE OF INSPECTOR GENERAL 
RESPONSE 
CMS concurred with both of our recommendations.  CMS noted that it 
has multiple efforts underway or planned that align with each 
suggested method to improve compliance with Medicares power 
wheelchair documentation requirements.  CMS will also forward the 
sampled claims we found to be in error to the appropriate contractors to 
identify and recover overpayments.  We will forward information on 
these claims to CMS under separate cover. 
 
 
 
   
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 T A B L E   O F   C O N T E N T S  
EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
 
 
I N T RO DUC T IO N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 
 
 
F I N D IN G S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 
  Three out of five claims for standard and complex             
rehabilitation power wheelchairs did not meet Medicare 
documentation requirements during the first half of 2007. . . . . . 14 
  Medicare documentation error rates varied by power  
  wheelchair type and supplier volume during the  
  first half of 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 
   
 
R E C O MMEN D A T ION S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 
  Agency Comments and Office of Inspector General Response . . . 24 
 
APPENDIXES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 
  A:  Medicares Power Wheelchair Documentation Requirements. 26 
 
  B:  Population and Sample Sizes by Stratum, First                             
        Half of 2007. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 
  C:  Incomplete Documentation Error Rates, First Half of 2007 . . 28 
  D:  Estimates and Confidence Intervals. . . . . . . . . . . . . . . . . . . . . 29 
  E:  Agency Comments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 
 
A C K NO WL E D G M E N T S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42   
   
 I N T R O D U C T I O N  
OBJECTIVE 
To determine the extent to which standard and complex rehabilitation 
power wheelchair claims met Medicare documentation requirements 
during the first half of calendar year 2007.     
BACKGROUND 
Between 1999 and 2003, Medicare payments for power wheelchairs 
increased approximately 350 percent, from $259 million to $1.2 billion, 
while overall Medicare program expenditures rose 28 percent.1  In 2005 
and 2006, the Centers for Medicare & Medicaid Services (CMS) revised 
its policies related to power wheelchair coverage and coding in response 
to numerous instances of fraud and abuse and the growth in Medicare 
power wheelchair expenditures.2  In 2007, approximately 173,300 
Medicare beneficiaries received power wheelchairs, at a total cost of 
$686 million.3 
Medicare beneficiaries are eligible to receive power wheelchairs under 
Medicare Part B coverage of durable medical equipment (DME).  Power 
wheelchairs are medically necessary for beneficiaries who cannot 
perform mobility-related activities of daily living using other mobility-
assistive equipment, such as a cane, manual wheelchair, or power-
operated scooter.4, 5  Most beneficiaries who require power wheelchairs 
are unable to walk and have severe upper body weakness because of a 
neurologic or muscular condition.6    
Medicare beneficiaries receive power wheelchairs from DME suppliers, 
which bill the Medicare program for reimbursement.   The supplier 
receives the power wheelchair prescription, along with documentation 
from the beneficiarys medical record to support the power wheelchairs 
 
1 71 Fed. Reg. 17021, 17022 (Apr. 5, 2006).  
2 CMS, Pub. No. 11272P, 2006 Fee Schedule Amounts for Power Mobility Devices Have 
Been Refined, November 2006. 
3 Office of Inspector General (OIG) analysis of CMSs claims data, July 2008. 
4 Medicare National Coverage Determinations Manual, Section 280.3.  Last modified in 
August 2005. 
5 Based on Medicares National Coverage Decision for Power Mobility Devices, mobility-
related activities of daily living include toileting, feeding, dressing, grooming, and bathing 
in customary locations within the home.   
6 CMSs Medicare Learning Network, Medicare Coverage of Power Mobility Devices:  
Power Wheelchairs and Power Operated Vehicles, April 2006. 
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necessity, from the prescribing physician.7  Based on the prescription, 
the supplier recommends a specific power wheelchair.  The physician 
must then review and approve the suppliers recommendation.8   
The beneficiary may choose to rent or purchase the power wheelchair.9  
However, most Medicare beneficiaries choose to purchase power 
wheelchairs.10 
To receive reimbursement, suppliers submit claims to Medicare for 
power wheelchairs using Healthcare Common Procedure Coding System 
codes (procedure codes).  Medicare determines the highest dollar 
amount that suppliers may be reimbursed for each procedure code (fee 
schedule amount).  Medicare pays 80 percent of the fee schedule amount 
and the beneficiary is responsible for the remaining 20 percent.     
Power Wheelchair Types 
Medicare covers more than 650 power wheelchair models.  Medicare 
assigns each model to 1 of Medicares 42 power wheelchair procedure 
codes (K0813K0864).11  The procedure code assignment is based on the 
models performance, patient weight capacity, seat type, portability, and 
power seating system capability.12   
Two types of power wheelchairs, standard and complex rehabilitation, 
accounted for over 80 percent of all Medicare power wheelchair 
expenditures in the first half of 2007.13  These are covered by Medicare 
 
7 Ibid.      
8 DME Medicare Administrative Contractors in jurisdictions A, B, C, and D, Local 
Coverage Determination (LCD) for Power Mobility Devices (hereinafter referred to as LCD 
for Power Mobility Devices).  Available online at 
http://www.cms.hhs.gov/mcd/viewlcd.asp?lcd_id=23598&lcd_version=18&show=all.  
Accessed on October 16, 2007.   
9 Ibid.  Medicare covers power wheelchairs under a capped rental arrangement.  
Medicare pays for a maximum of 13 continuous months of rental.  Should a beneficiary 
choose to rent his or her power wheelchair, the supplier must transfer ownership to the 
beneficiary after the 13th month.  
10 In the first half of 2007, new power wheelchair purchases accounted for 95 percent of 
all Medicare power wheelchair expenditures.  (OIG analysis of 2007 CMS claims data, 
January 2009.)   
11 Medicare has not assigned power wheelchairs to procedure codes K0817K0819, 
K0832K0834, and K0844K0847. 
12 Statistical Analysis DME Regional Carrier, Power Mobility Device Coding Guidelines, 
August 3, 2006.  
13 OIG analysis of claims from the National Claims History file submitted under 
procedure codes K0823 and K0835K0864 with dates of service from January 1 to June 30, 
2007, processed as of June 30, 2007.   
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I N T R O D U C T I O N  
under 27 procedure codes, which include 395 power wheelchair 
models.14 
Standard power wheelchairs.  In the first half of 2007, procedure code 
K0823 was the most frequently reimbursed power wheelchair type; it 
accounted for nearly three-quarters of Medicares power wheelchair 
claims and expenditures.15  As of July 2009, Medicare covered 98 power 
wheelchair models under procedure code K0823.16  We refer to K0823 
power wheelchairs as standard power wheelchairs in this report. 
Standard power wheelchairs are designed to provide basic, daily 
mobility for persons weighing less than 300 pounds and feature an 
automotive-style seat.  These power wheelchairs cannot be upgraded 
with power options (e.g., a powered seating system) or other electronic 
features (e.g., a device to enable the user to control the chair by sipping 
and puffing through a straw).17  Medicares 2007 fee schedule amount 
for standard power wheelchairs was $4,024.18, 19 
Complex rehabilitation power wheelchairs.  Medicare payments for complex 
rehabilitation power wheelchairs accounted for less than 7 percent of 
power wheelchair claims and expenditures in the first half of 2007.20   
As of July 2009, Medicare covered 297 complex rehabilitation power 
wheelchair models under 26 procedure codes.21, 22  
Complex rehabilitation power wheelchairs can be upgraded with power 
options and other electronic features to accommodate beneficiaries 
specific mobility needs.23  For a beneficiary to receive many types of 
 
14 Medicare Pricing, Data Analysis, and Coding (PDAC) contractor, Motorized 
Wheelchair Product Classification List, July 16, 2009.   
15 OIG analysis of claims from the National Claims History file submitted under 
procedure code K0823 with dates of service from January 1 to June 30, 2007, processed as of 
June 30, 2007.   
16 Medicare PDAC contractor, op. cit. 
17 LCD for Power Mobility Devices, Code Specific Requirements and Definitions. 
18 DME, Prosthetics, Orthotics, and Supplies (DMEPOS) 2007 Fee Schedule.   
19 In January 2009, the fee schedule amount for standard power wheelchairs was 
reduced by 9.5 percent, to $3,641. 
20 OIG analysis of claims from National Claims History file submitted under procedure 
codes K0835K0864 with dates of service from January 1 to June 30, 2007, processed as of 
June 30, 2007. 
21 DMEPOS Supplier Quality Standards, August 2007, p. 11.  Complex rehabilitation 
procedure codes are K0835K0843 and K0848K0864. 
22 Medicare PDAC contractor, op. cit. 
23 LCD for Power Mobility Devices, Code Specific Requirements. 
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I N T R O D U C T I O N  
complex rehabilitation power wheelchairs, the beneficiarys mobility 
limitation must result from a neurological condition, muscle disease, or 
skeletal deformity.24  Medicares 2007 fee schedule amounts for complex 
rehabilitation power wheelchairs ranged from $4,132 to $11,965.25, 26  
Medicare Documentation Requirements for Power Wheelchairs 
Section 1833(e) of the Social Security Act states in part that no 
payment shall be made to any provider . . . unless there has been 
furnished such information as may be necessary in order to determine 
the amounts due such provider.  The Social Security Act, Code of 
Federal Regulations, Medicares National Coverage Decision for Power 
Mobility Devices, and Medicares Local Coverage Determinations (LCD) 
for Power Mobility Devices specify the circumstances under which 
power wheelchairs are reasonable and necessary.27, 28  To meet coverage 
requirements, these guidances require that suppliers maintain a variety 
of documents that support the beneficiarys need for, and the 
appropriateness of, the provided power wheelchair.   
For any item to be covered by Medicare, it must meet all . . . applicable 
Medicare statutory and regulatory requirements.29  Medicare requires 
the following documentation to support power wheelchair claims:   
 power wheelchair prescription, 
 supporting documentation from the beneficiarys medical record 
(hereinafter supporting documentation), 
 specialty evaluation report (for complex rehabilitation power 
wheelchairs only), 
 detailed product description,  
 
24 LCD for Power Mobility Devices, Indications and Limitations of Coverage and/or 
Medical Necessity. 
25 DMEPOS 2007 Fee Schedule.   
26 In January 2009, the fee schedule amounts were reduced by 9.5 percent, to between      
$3,739 and $10,828.   
27 See 42 U.S.C.  1395m(a)(1)(E)(iv),  1834(a)(1)(E)(iv) of the Social Security Act,        
42 CFR 410.38(c)(2), Medicares National Coverage Decision for Power Mobility Devices, 
and LCD for Power Mobility Devices.  LCDs provide guidance to the public and the medical 
community within their jurisdictions.  CMS requires that the power wheelchair LCDs be 
the same for each jurisdiction to ensure uniformity for DMEPOS suppliers that operate 
nationally. 
28 The term power mobility device refers to both power wheelchairs and power-operated 
vehicles, which are commonly referred to as scooters.  LCD for Power Mobility Devices.  
29 LCD for Power Mobility Devices. 
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 home assessment report, and 
 proof of delivery.30 
Each of these documents is described in more detail below.  For many 
of these documents, the LCD includes requirements related to the 
documents contents and the timeframes within which the supplier 
should create or receive the documents.    
Prescription.  Medicare requires suppliers to obtain the power wheelchair 
prescription from the physician who examined the beneficiary.31, 32  The 
supplier must receive the prescription within 45 days of the 
beneficiarys examination date and before delivering the power 
wheelchair to the beneficiary.33  Power wheelchair prescriptions must 
include seven elements:   
1.  beneficiary name,  
2.  examination date, 
3.  diagnoses and conditions that support the claim,  
4.  item description,  
5.  expected length of time the beneficiary will need the chair,  
6.  prescribing physician signature, and  
7.  prescription date.   
 
30 The LCD for Power Mobility Devices requires all listed documents, other than proof of 
delivery, which is required by 42 CFR  424.57(c)(12).   
31 LCD for Power Mobility Devices, Documentation Requirements.  In addition to being 
part of the power wheelchair LCD, this requirement is codified in the Social Security Act at 
section 1843(a)(1)(E)(iv) and is also found in the regulations issued by CMS at 42 CFR          
 410.38(c)(2)(ii). 
32 Section 302(a)(2) of the Medicare Prescription Drug, Improvement, and Modernization 
Act of 2003, P.L.No. 108-173, amended the Social Security Act to include section 
1834(a)(1)(E)(iv), requiring that a physician or other treating practitioner assess the 
beneficiarys need for a power wheelchair during a face-to-face examination before writing a 
prescription.  See 42 U.S.C.  1395m(a)(1)(E)(iv); section 1843(a)(1)(E)(iv) of the Social 
Security Act.  If a specialist, such as a physical or occupational therapist, performs the 
evaluation, a physician still must review the examination report and sign and date it to 
meet Medicare requirements.  See LCD for Power Mobility Devices.    
33 See LCD for Power Mobility Devices.  The 45-day period does not include the time 
required by the supplier to provide the power wheelchair to the beneficiary, as time may be 
required to assemble or adjust it to meet the specific needs of the beneficiary.   
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The supplier must document the date it receives the prescription using 
a date stamp or an equivalent method.34 
Supporting documentation.  The supplier must also receive documentation 
from the prescribing physician that supports the medical necessity for 
the power wheelchair.35  The supplier must receive the supporting 
documentation within 45 days after the physicians examination of the 
beneficiary and before the power wheelchairs delivery.36 
The medical record from the beneficiarys examination is often sufficient 
supporting documentation to demonstrate the medical necessity for the 
power wheelchair.37  However, the physicians medical record notes 
from the examination must clearly indicate that the primary reason for 
the visit was to assess the beneficiarys need for a power wheelchair.  A 
physician-completed form or letter of attestation may not serve as the 
supporting documentation.  The supplier must document the date it 
receives the supporting documentation using a date stamp or an 
equivalent method.38   
Specialty evaluation report.  A beneficiary who receives a complex 
rehabilitation power wheelchair must receive a specialty evaluation, in 
addition to the physicians initial examination.  The specialty evaluation 
report must document the medical necessity for the power wheelchair 
and each recommended option and accessory.  A medical professional 
with experience in rehabilitation power wheelchair evaluations, such as 
an occupational or physical therapist, must perform the specialty 
evaluation.39    
Detailed product description.  Based on the physicians prescription, the 
supplier determines the specific power wheelchair that is appropriate 
for the beneficiary.  The supplier must prepare a detailed product 
description that lists the specific power wheelchair and all options and 
accessories.  This document should include a procedure code, a 
 
34 LCD for Power Mobility Devices. 
35 See 42 CFR 410.38(c)(2)(iii); LCD for Power Mobility Devices, Documentation 
Requirements.   
36 Ibid.  The 45-day period does not include the time required by the supplier to provide 
the power wheelchair to the beneficiary, as additional time may be required to make or 
adjust it to meet the specific needs of the beneficiary.   
37 Preamble to Final Rule:  42 CFR Part 410.38(c), p. 10.   
38 LCD for Power Mobility Devices.   
39 LCD for Power Mobility Devices, Documentation Requirements. 
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description, a fee schedule amount, and the charge for each item the 
supplier plans to bill.40   
The supplier is required to submit the detailed product description for 
the prescribing physicians approval.  The supplier must receive the 
signed and dated detailed product description from the physician before 
delivering the power wheelchair to the beneficiary.  The supplier must 
document the date it receives the detailed product description using a 
date stamp or an equivalent method. 
Home assessment report.  The supplier must perform an onsite home 
assessment before or during the power wheelchairs delivery to verify 
that the beneficiary can adequately maneuver the chair in his or her 
home.  The assessment should consider the homes layout, surfaces, etc.  
The supplier must maintain a written report of the assessment.41   
Proof of delivery.  The supplier must maintain documentation, such as a 
delivery slip or an invoice, to show that the power wheelchair was 
delivered to the beneficiary.42  
Appendix A contains a summary of Medicares power wheelchair 
documentation requirements.      
Prior Office of Inspector General Work 
OIG has conducted several evaluations of power wheelchairs in the 
Medicare program.43  In 2001, OIG evaluated suppliers compliance 
with power wheelchair documentation requirements.  That report found 
that over half of reviewed claims paid in 2001 under the most frequently 
reimbursed procedure code (K0011) at the time were missing 
documentation, had incomplete documentation, or had documentation 
that was dated after the claims date of service.  CMS has since revised 
and added to Medicares power wheelchair documentation 
requirements.  For example, in 2006, CMS replaced the Certificate of 
Medical Necessity with the requirement that suppliers obtain the 
 
40 Ibid.  All options and accessories for power wheelchairs are billed as separate items. 
41 Ibid. 
42 42 CFR  424.57(c)(12).  Proof of delivery is required by one of the 26 application 
certification standards that every Medicare DMEPOS supplier must meet to obtain and 
retain its billing privileges. 
43 Department of Health and Human Services (HHS) OIG, A Comparison of Prices for 
Power Wheelchairs in the Medicare Program, OEI-03-03-00460, April 2004; HHS OIG, 
Medicare Payments for Power Wheelchairs, OEI-03-02-00600, April 2004; HHS OIG, A 
Comparison of Medicare Program and Consumer Internet Prices for Power Wheelchairs, 
OEI-04-07-00160, October 2007.   
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I N T R O D U C T I O N  
prescription and supporting documentation from the prescribing 
physician.44   
Office of Inspector General Power Wheelchair Evaluation Series 
OIG is conducting a series of evaluations of Medicares payments for 
power wheelchairs supplied to Medicare beneficiaries in the first half of 
2007.  In addition to issuing this report, OIG issued separate reports on 
suppliers costs to purchase power wheelchairs and the services that 
suppliers performed in conjunction with providing the chairs, suppliers 
costs to purchase power wheelchair batteries, and miscoded power 
wheelchair claims.45  OIG also plans to issue a report on the 
appropriateness (e.g., the medical necessity) of power wheelchair claims.  
In addition to determining whether beneficiary medical records 
supported the medical necessity of the power wheelchair, OIG will 
determine whether documentation from the suppliers and prescribing 
physicians was consistent. 
METHODOLOGY 
Scope 
This evaluation focused on standard and complex rehabilitation power 
wheelchairs supplied to Medicare beneficiaries in the first half of 2007.  
We reviewed documentation for a random sample of 375 standard and 
complex rehabilitation power wheelchair claims to determine the extent 
to which the claims met documentation requirements from the LCD for 
Power Mobility Devices, as well as the proof-of-delivery requirement 
from Medicares supplier standards. 
We did not perform a medical record review to determine whether the 
supporting documentation or written report of the specialty evaluation 
submitted by suppliers supported the medical necessity of the power 
wheelchairs.  In addition, we did not determine whether notes from the 
beneficiary examinations indicated that mobility examinations were the 
 
44 Prior to 2005, suppliers were required to submit a Certificate of Medical Necessity 
with power wheelchair claims.  The Certificate of Medical Necessity collected information 
relating to the equipment ordered from the supplier and information on the beneficiarys 
medical condition from the prescribing physician.  CMSs Medicare Learning Network, 
Medicare Coverage of Power Mobility Devices:  Power Wheelchairs and Power Operated 
Vehicles, April 2006.   
45 HHS OIG, Power Wheelchairs in the Medicare Program:  Supplier Acquisition Costs 
and Services, OEI-04-07-00400, August 2009; Supplier Acquisition Costs for Power 
Wheelchair Batteries in the Medicare Program (in progress); and Miscoded Claims for 
Power Wheelchairs in the Medicare Program, OEI-04-07-00403, July 2009. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  8   
   
I N T R O D U C T I O N  
reason for the visits.  Finally, we did not determine whether specialty 
evaluations were performed by medical professionals with experience in 
complex rehabilitation power wheelchair evaluations.  Appendix A 
distinguishes between the requirements that we reviewed and those 
that we did not review. 
Sample Selection 
Our population consisted of new, nonrental power wheelchair claims 
from CMSs National Claims History DME Standard Analytical File 
with dates of service during the first half of 2007.46  We removed claims 
associated with suppliers that were inactive or whose billing privileges 
had been revoked and claims associated with suppliers or prescribing 
physicians that were under OIG investigation.47, 48  After removing 
these claims, the population from which we sampled included 93 
percent of standard and 91 percent of complex rehabilitation power 
wheelchair claims.49   We grouped the resulting population into three 
strata:  
1.  standard power wheelchair claims submitted by low-volume 
suppliers (those that submitted fewer than 10 standard power 
wheelchair claims in the first half of 2007),50  
 
46 The final date to submit claims for power wheelchairs that were provided during the 
first half of 2007 was December 31, 2008.  We analyzed claims CMS processed as of June 
30, 2007.  Suppliers had submitted 79 percent of claims for power wheelchairs that were 
provided during the first half of 2007 at the time we selected our sample.     
47 We removed claims according to the suppliers status at the time that we selected the 
sample. 
48 Pursuant to 42 CFR  424.520(a), to maintain Medicare billing privileges after initial 
enrollment, suppliers must comply with Medicare regulations and relevant Federal and 
State requirements.  Pursuant to 42 CFR  424.535, Medicare may revoke a suppliers 
billing privileges because of a felony, noncompliance with enrollment requirements, etc.  
Pursuant to 42 CFR  424.540, Medicare also may deactivate a suppliers billing privileges 
when the supplier does not submit a claim for a full year or when the supplier fails to report 
a change to the information provided on the enrollment application.   
49 We removed 3,430 standard and 301 complex rehabilitation power wheelchair claims 
because of the suppliers Medicare enrollment status or ongoing investigations.  After 
removing these, our population consisted of 43,133 standard and 3,001 complex 
rehabilitation power wheelchair claims.       
50 We divided the standard power wheelchair population by supplier volume based on the 
distribution of suppliers and claims.  Twenty-five percent of suppliers received Medicare 
reimbursement for 10 or more standard power wheelchair claims during the first half of 
2007, and these claims accounted for 83 percent of all standard power wheelchair claims. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  9   
   
I N T R O D U C T I O N  
2.  standard power wheelchair claims submitted by high-volume 
suppliers (those that submitted 10 or more standard power 
wheelchair claims in the first half of 2007), and  
3.  complex rehabilitation power wheelchair claims. 
We sampled 375 total claims by selecting simple random samples of    
125 claims from each stratum.51  Appendix B provides the number of 
claims, amount of Medicare expenditures, and number of suppliers for 
the population and sample, by stratum.   
Data Collection 
We asked suppliers to submit the following documents to support 
their power wheelchair claims:  prescription, supporting 
documentation, specialty evaluation report (for complex rehabilitation 
chairs only), detailed product description, home assessment report, 
and proof of delivery.  We also requested documentation identifying 
the dates the supplier received the prescription, supporting 
documentation, and the detailed product description from the 
prescribing physician.   
Before mailing the documentation requests, we asked representatives 
of three power wheelchair suppliers to review the request for clarity 
and familiarity of language.  We made changes to the request based 
on their feedback.    
We obtained suppliers addresses from the National Supplier 
Clearinghouse data file.  We mailed the documentation requests to 
the power wheelchair suppliers in our sample.  We mailed up to three 
requests and telephoned nonresponding suppliers to ensure they had 
received the requests.  We did not receive responses from suppliers of 
11 claims.52  Of these, the supplier of one claim did not respond, 
although we were able to verify the suppliers receipt of our request.  
We considered this claim as lacking documentation and included it in 
our analysis.  We excluded the remaining 10 claims from our sample 
because we could not contact the suppliers or verify that they received 
our request.  Therefore, we used a total of 365 claims in our analysis, 
for a response rate of 97 percent.    
 
 
51 All evaluations in the current OIG power wheelchair evaluation series use this sample.  
52 We referred suppliers that did not respond to our request to CMS and shared this 
information with OIGs Office of Investigations. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  10   
   
I N T R O D U C T I O N  
Data Analysis 
We determined whether suppliers submitted the requested 
documentation for the 365 claims.  We reviewed the documentation to 
determine the extent to which they met Medicare documentation 
requirements.   
Prescription.  We identified all claims for which the suppliers submitted 
prescriptions.  For those that did, we determined whether the 
prescriptions included all seven required elements:  beneficiary name, 
beneficiary examination date, diagnoses and conditions that support the 
claim, item description, expected length of time the beneficiary will need 
the chair, prescribing physician signature, and prescription date.   
We determined whether suppliers submitted documentation of the dates 
they received the prescriptions from the prescribing physicians.  For 
claims that had these dates, we determined whether the suppliers 
received the prescriptions within 45 days after the beneficiary 
examinations.  To make that determination, we compared the dates the 
suppliers received the prescriptions with the dates of the beneficiaries 
examinations (a required element on the prescription).  We compared 
the dates the suppliers received prescriptions with the claims dates of 
service to determine whether the suppliers received the prescriptions 
before the chairs were delivered.   
Supporting documentation.  We identified all claims for which suppliers 
submitted supporting documentation from the beneficiaries medical 
records.  We did not count physician-completed forms or letters of 
attestation as supporting documentation because Medicares LCD states 
that these do not substitute for the beneficiaries medical records.   
We determined whether suppliers submitted documentation of the date 
they received the supporting documentation from the prescribing 
physicians.  For claims that had these dates, we determined whether 
the suppliers received the supporting documentation within 45 days 
after the beneficiary examinations using the same approach as for the 
prescriptions.   
Specialty evaluation report.  We identified complex rehabilitation power 
wheelchair claims for which the suppliers submitted specialty 
evaluation reports.  
Detailed product description.  We identified all claims for which the 
suppliers submitted detailed product descriptions.  We determined 
whether the detailed product description listed the specific power 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  11   
   
I N T R O D U C T I O N  
wheelchair base and all options and accessories for which the supplier 
billed Medicare.  For each item the supplier billed, we determined 
whether the detailed product description included a procedure code, 
description, Medicare fee schedule amount, and supplier charge.   
We determined whether the prescribing physician approved the detailed 
product description by signing and dating it before the power 
wheelchair was delivered to the beneficiary.  We also determined 
whether suppliers submitted documentation of the dates they received 
the detailed product descriptions from the prescribing physicians.   
Home assessment report.  We identified all claims for which the suppliers 
submitted home assessment reports.  We determined whether the home 
assessment was performed before or during the chairs delivery.  We 
also determined whether the home assessment report addressed the 
physical layout of the beneficiarys home.   
Proof of delivery.  We identified all claims for which the suppliers 
submitted proof of delivery.  
We identified all claims that did not meet one or more of the 
documentation requirements that we reviewed.  We also distinguished 
between document not submitted errors and incomplete document 
errors.  We considered a document to be incomplete if it did not meet all 
Medicare requirements (for example, if it was missing a required piece 
of information or was not received within the required timeframe).  We 
projected error rates for these claims and compared the error rates by 
standard versus complex rehabilitation power wheelchairs and, for 
standard power wheelchairs, by supplier volume.53   
For claims that had errors, we calculated the expenditures (improper 
payments) using Medicare-allowed amounts from the National Claims 
History data.  
Limitations 
We did not review claims compliance with all the requirements from 
Medicares LCD for Power Mobility Devices.  For example, we did not 
determine whether the supporting documentation or written report of 
the specialty evaluation supported the medical necessity of the chair.  
Therefore, our results may underestimate the documentation-related 
error rate.   
 
53 We used SAS and SUDAAN survey data analysis software to project our sample 
results nationally. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  12   
   
I N T R O D U C T I O N  
 
Standards 
This study was conducted in accordance with the Quality Standards for 
Inspections approved by the Council of the Inspectors General on 
Integrity and Efficiency. 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  13   
   
 F I N D I N G S  
Three out of five claims for standard and  Sixty percent of claims for standard 
complex rehabilitation power wheelchairs did  and complex rehabilitation power 
wheelchairs that Medicare 
not meet Medicare documentation requirements 
beneficiaries received during the 
during the first half of 2007 
first half of 2007 did not meet one 
or more documentation requirement.54  Medicare requires suppliers to 
obtain a variety of documents that support the beneficiarys need for, 
and the appropriateness of, the provided power wheelchairs.  Suppliers 
must also have proof of the power wheelchairs delivery.  Claims that 
did not meet all documentation requirements accounted for $112 million 
in improper Medicare payments, out of $189 million total allowed by 
Medicare during the 6-month period.  Beneficiaries were responsible for 
paying $22 million of this amount.   
Standard and complex rehabilitation power wheelchair claims were 
more likely to meet some documentation requirements than others.  
Two out of five power wheelchair claims had multiple errors.  In 
addition, suppliers submitted incomplete documents almost three times 
as often as they failed to submit required documents.  The specialty 
evaluation report was one of the documents most often not submitted by 
complex rehabilitation power wheelchair suppliers. 
Appendix C presents error rates for requirements related to the 
documents contents and the time frames within which the supplier 
should create or receive the documents (i.e., incomplete documentation 
errors).  Appendix D provides the confidence intervals for estimates of 
all documentation error rates and associated improper payments.   
Standard and complex rehabilitation power wheelchair claims were more 
likely to meet some documentation requirements than others 
Power wheelchair claims varied in the extent to which they did not meet 
Medicare requirements for the prescription, supporting documentation, 
specialty evaluation report, detailed product description, home 
assessment report, and proof of delivery.  Error rates ranged from           
1 percent of claims for which the suppliers did not submit proof of 
delivery to 40 percent of claims for which the supporting documentation 
and detailed product descriptions were not submitted or were 
incomplete.   
 
54 Standard power wheelchairs accounted for approximately three-quarters of Medicare 
power wheelchair expenditures in the first half of 2007.  Complex rehabilitation power 
wheelchairs accounted for 6 percent.  
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  14   
   
F I N D I N G S  
Table 1 presents the error rates for each documentation requirement 
and in total.  
 
Table 1:  Medicare Documentation Error Rates for Standard and 
Complex Rehabilitation Power Wheelchair Claims, First Half of 2007 
 
Documentation Requirement  Error Rate 
 
Supporting documentation  40% 
 Detailed product description  40% 
Prescription  32% 
 
Specialty evaluation report*  2% 
 Home assessment report  18% 
Proof of delivery  1% 
 
(Overlapping errors)  (73%) 
 
     Total  60% 
* Requirement does not apply to standard power wheelchairs.  Thirty percent of complex rehabilitation 
 
power wheelchair claims did not meet the specialty evaluation report requirement.   
Note:  Overlapping errors are subtracted to obtain the total. 
 
Source:  OIG analysis of supplier documentation, 2009. 
 
 
Supporting documentation.  Forty percent of power wheelchair claims did 
not have complete supporting documentation, such as physician notes or 
test results, from the beneficiaries medical records.  Instead of a 
Certificate of Medical Necessity, power wheelchair suppliers must 
obtain documentation from the beneficiarys medical record that clearly 
supports the medical necessity for the power wheelchair from the 
prescribing physician.55  Claims that did not have complete supporting 
documentation resulted in $75 million in improper payments by 
Medicare and its beneficiaries.   
Although suppliers of only 2 percent of claims did not submit any 
supporting documentation, suppliers of another 38 percent of claims 
submitted supporting documentation that did not meet all of Medicares 
requirements.  For example, the supporting documentation for             
20 percent of claims did not include the physicians notes from the 
beneficiaries medical records.  Instead, these claims were improperly 
supported by either physician-completed forms or letters of attestation.   
In addition, suppliers did not always meet the 45-day requirement.  
Specifically, suppliers of 9 percent of claims did not receive the 
 
55 We did not conduct a medical record review to determine whether this documentation 
supported the medical necessity of the power wheelchairs.  OIG plans to issue a separate 
report on the appropriateness (e.g., the medical necessity) of power wheelchair claims.   
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  15   
   
F I N D I N G S  
documentation within 45 days after the beneficiarys examination and, 
for 8 percent of claims, suppliers did not receive the documentation 
before the delivery date.  Other claims did not include the date the 
supplier received the supporting documentation.  For those that did, 
suppliers received the supporting documentation within a median of       
7 days after the beneficiarys examination.  However, the maximum 
amount of time was 405 days, approximately 14 months after the 
examination.  
Detailed product description.  Forty percent of power wheelchair claims 
did not have a complete detailed product description.  The detailed 
product description is the suppliers recommendation of the specific 
power wheelchair and accessories that are appropriate for the 
beneficiary.  The prescribing physician must approve the suppliers 
recommendation before the chair is provided.  Claims with missing or 
incomplete detailed product descriptions resulted in $74 million in 
improper payments by Medicare and its beneficiaries.   
Although suppliers of 14 percent of claims did not submit a detailed 
product description, suppliers of another 26 percent of claims submitted 
detailed product descriptions that did not meet all of Medicares 
requirements.  Without a complete detailed product description, 
Medicare claim reviewers cannot determine whether the physician 
approved the suppliers suggested power wheelchair and accessories 
before the beneficiary received his or her power wheelchair.   
For example, some detailed product descriptions did not include all 
items for which the supplier billed Medicare.56  In addition, detailed 
product descriptions did not always include the date the supplier 
received the document from the prescribing physician, and others were 
received by the supplier after the chairs delivery.  Finally, detailed 
product descriptions were not always signed and dated by the 
prescribing physician.    
Prescription.  Thirty-two percent of power wheelchair claims did not 
have a complete prescription.  These claims resulted in $60 million in 
improper payments by Medicare and its beneficiaries.   
Although suppliers of all but 1 percent of claims submitted the power 
wheelchair prescription, suppliers of 31 percent of claims submitted 
 
56 For each billed item, the supplier must include the procedure code, description, 
Medicare fee schedule amount, and suppliers charge. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  16   
   
F I N D I N G S  
prescriptions that did not meet all of Medicare requirements.  For 
example, 16 percent of prescriptions did not include all seven required 
elements, such as the date of the beneficiarys examination and the 
length of time the beneficiary needed the power wheelchair.   
In addition, suppliers did not always meet the 45-day requirement.  
Specifically, suppliers of 6 percent of claims did not receive the 
prescription within 45 days after the beneficiarys examination and, for 
another 6 percent of claims, suppliers did not receive the prescription 
before the delivery date.  Other claims did not include the date the 
supplier received the prescription.  For those that did, suppliers 
received the prescription within a median of 7 days after the 
beneficiarys examination.  However, the maximum amount of time was 
393 days, approximately 13 months after the examination.   
Specialty evaluation report.  Beneficiaries who receive complex 
rehabilitation power wheelchairs must receive a specialty evaluation by 
a medical professional with experience in complex rehabilitation power 
wheelchair evaluations.57  Complex rehabilitation power wheelchair 
claims that were not supported by a written report of the specialty 
evaluation represented 2 percent of all standard and complex 
rehabilitation power wheelchair claims.58  However, these claims 
represented 30 percent of complex rehabilitation power wheelchair 
claims.  These claims resulted in $5 million in improper payments by 
Medicare and its beneficiaries.   
Home assessment report.  Eighteen percent of power wheelchair claims 
did not have a complete home assessment report.  The suppliers home 
assessment verifies that the beneficiary can adequately maneuver the 
power wheelchair in his or her home.  Claims with missing or 
incomplete home assessment reports resulted in $34 million in improper 
payments by Medicare and its beneficiaries.   
Although suppliers of 10 percent of claims did not submit a home 
assessment report, suppliers of another 8 percent of claims submitted 
home assessment reports that did not meet Medicares requirements.  
 
57 The specialty evaluation requirement does not apply to standard power wheelchairs.   
58 We did not conduct a medical record review to determine whether the specialty 
evaluation report supported the medical necessity of the complex rehabilitation power 
wheelchairs and their options and accessories.  OIG plans to issue a separate report on the 
appropriateness (e.g., the medical necessity) of claims for power wheelchairs and certain 
options and accessories supplied with them.   
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  17   
   
F I N D I N G S  
Specifically, suppliers of 3 percent of claims did not evaluate the 
physical layout of the beneficiarys home in their reports.  These 
suppliers usually submitted a form certifying that a home assessment 
was conducted but provided little to no information about the homes 
dimensions, surfaces, or stairways.  In addition, suppliers sometimes 
conducted the home assessment after the delivery of the chair. 
Proof of delivery.  Suppliers of 1 percent of power wheelchair claims did 
not submit proof of the chairs delivery to the beneficiary.59   
Two out of five claims had multiple documentation errors 
Thirty-eight percent of power wheelchair claims had multiple 
documentation errors.  Suppliers of claims with multiple errors did not 
submit required documents and/or submitted incomplete documents.  
Incomplete documents did not have all required information or were not 
received within the required timeframe.  Claims with multiple 
documentation errors accounted for $71 million in improper Medicare 
payments.  
Table 2 presents the percentage of claims and improper payments that 
Medicare allowed, by the number of documents per claim that did not 
meet Medicare requirements.   
Table 2:  Number of Medicare Documentation Errors per Power 
Wheelchair Claim, First Half of 2007 
Number of Documents per 
Claim That Did Not Meet  Payments Allowed 
Medicare Requirements   Claims (Percentage)*  (Millions) 
One   22%  $41 
Two   13%  $25 
Three   16%  $30 
More than three  8%  $16 
     Total  60%  $112 
* Column does not sum because of rounding. 
Source:  OIG analysis of supplier documentation, 2009. 
 
Suppliers submitted incomplete documents almost three times as often as 
they did not submit required documents  
Suppliers of 20 percent of standard and complex rehabilitation power 
wheelchair claims did not submit one or more documents required by 
 
59 We do not report improper payments by Medicare and its beneficiaries for claims that 
did not have proof of delivery because the confidence interval contained zero.   
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  18   
   
F I N D I N G S  
Medicare.  Suppliers of 56 percent of claims submitted one or more 
incomplete documents.  Sixteen percent of claims had both types of 
error:  suppliers failed to submit at least one document and submitted 
at least one incomplete document.   
Table 3 presents the error rates for claims for which the supplier did not 
submit all required documents and those for which the supplier submitted 
an incomplete document. 
 
Table 3:  Not Submitted and Incomplete Medicare Documentation Error 
 
Rates for Power Wheelchair Claims, First Half of 2007 
 
Type of Documentation Error  Error Rate 
  Supplier did not submit all required documents   20% 
Supplier submitted at least one incomplete document  56% 
 
(Overlapping errors:  supplier did not submit all required 
documents and submitted at least one incomplete document )  (16%) 
 
     Total   60% 
  Note:  Overlapping errors are subtracted to obtain the total. 
Source:  OIG analysis of supplier documentation, 2009. 
 
The specialty evaluation report was one of the documents most often not 
submitted by complex rehabilitation power wheelchair suppliers.   
Beneficiaries who require complex rehabilitation power wheelchairs 
typically have mobility limitations that result from a neurological 
condition, muscle disease, or skeletal deformity; therefore, Medicare 
requires that these beneficiaries receive a specialty evaluation, in 
addition to the physicians initial examination.  However, suppliers of 
30 percent of complex rehabilitation power wheelchair claims did not 
submit a written report of the beneficiarys specialty evaluation.  The 
specialty evaluation report and detailed product description were the 
documents suppliers of complex rehabilitation power wheelchairs most 
often failed to submit.60   
 
 
 
 
60 Suppliers of 22 percent of complex rehabilitation power wheelchair claims did not 
submit a detailed product description.  The differences between these error rates and other 
complex rehabilitation power wheelchair error rates are significant at the 95-percent 
confidence level. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  19   
   
F I N D I N G S  
Complex rehabilitation power 
Medicare documentation error rates varied by 
wheelchair claims had a higher 
power wheelchair type and supplier volume 
documentation error rate than 
during the first half of 2007   
standard power wheelchair claims 
during the first half of 2007.  For 
standard power wheelchairs, claims submitted by low-volume suppliers 
had a higher error rate than those from high-volume suppliers.    
Complex rehabilitation power wheelchair claims had a higher 
documentation error rate than standard power wheelchair claims 
Complex rehabilitation power wheelchair claims met all documentation 
requirements less frequently than standard power wheelchair claims.61  
Ninety-three percent of complex rehabilitation power wheelchair claims 
had multiple errors, while 58 percent of standard power wheelchair 
claims had multiple errors.   
Table 4 presents the error rates associated with each documentation 
requirement for standard and complex rehabilitation wheelchair claims.   
 
Table 4:  Comparison of Medicare Documentation Error Rates for Standard 
  and Complex Rehabilitation Power Wheelchair Claims, First Half of 2007 
  Error Rate  
Standard Power  Complex Rehabilitation 
 
Documentation Requirement  Wheelchairs  Power Wheelchairs 
  Supporting documentation  39%  61% 
Detailed product description  38%  61% 
 
Prescription  30%  58% 
  Specialty evaluation report*  NA  30% 
Home assessment report  18%  28% 
 
Proof of delivery  1%  1% 
  (Overlapping errors)  (68%)  (146%) 
     Total  58%  93% 
 
* Requirement does not apply to standard power wheelchairs. 
Note:  Overlapping errors are subtracted to obtain the total. 
 
Source:  OIG analysis of supplier documentation, 2009. 
 
 
61 Difference is statistically significant at the 95-percent confidence level. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  20   
   
F I N D I N G S  
Complex rehabilitation power wheelchair claims had higher 
documentation error rates for all requirements, except proof of 
delivery.62, 63   In the first half of 2007, suppliers submitted over             
13 times more standard than complex rehabilitation power wheelchair 
claims.  The greater number of standard power wheelchair claims 
strongly influenced the combined error rates and resulted in higher 
improper payments for standard power wheelchairs than for complex 
rehabilitation power wheelchairs.  Documentation errors for standard 
power wheelchairs resulted in $97 million in improper payments, while 
errors for complex rehabilitation power wheelchair claims resulted in 
$15 million in improper payments.   
Standard power wheelchair claims submitted by low-volume suppliers had a 
higher documentation error rate than those from high-volume suppliers 
Standard power wheelchair claims submitted by low-volume suppliers 
met all documentation requirements less frequently than those 
submitted by high-volume suppliers.64  Fifty-five percent of claims 
submitted by suppliers that provided 10 or more standard power 
wheelchairs in the first half of 2007 (high-volume suppliers) had 
multiple errors.  Seventy-two percent of claims submitted by suppliers 
that provided fewer than 10 standard power wheelchairs (low-volume 
suppliers) had multiple errors.   
Table 5 presents the error rates associated with each documentation 
requirement for high- and low-volume suppliers.  
 
 
 
 
 
 
 
 
 
 
 
 
62 Differences are statistically significant at the 95-percent confidence level. 
63 Complex rehabilitation power wheelchair claims are subject to an additional 
requirement.  The specialty evaluation report requirement does not apply to standard 
power wheelchair claims.   
64 Difference is statistically significant at the 95-percent confidence level. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  21   
   
F I N D I N G S  
T able 5:  Comparison of Medicare Documentation Error Rates for 
Standard Power Wheelchair Claims, by Supplier Volume, First Half of 2007 
 
Error Rate 
Documentation Requirement  High-Volume Suppliers*  Low-Volume Suppliers 
Supporting documentation  36%  51% 
Detailed product description  36%  48% 
Prescription  29%  37% 
Home assessment report  17%  18% 
Proof of delivery  1%  3% 
(Overlapping errors)  (65%)  (85%) 
     Total  55%  72% 
* Column does not sum because of rounding. 
Note:  Overlapping errors are subtracted to obtain the total. 
Source:  OIG analysis of supplier documentation, 2009. 
 
Because high-volume suppliers provide more standard power wheelchairs 
than low-volume suppliers, claims submitted by high-volume suppliers 
accounted for more improper payments for documentation errors than did 
claims submitted by low-volume suppliers.65  Documentation errors for 
standard power wheelchairs resulted in $77 million in improper payments 
for claims submitted by high-volume suppliers and $20 million for claims 
submitted by low-volume suppliers.  
 
65 Eighty-three percent of standard power wheelchairs were supplied by high-volume 
suppliers in the first half of 2007.   
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  22   
   
 R E C O M M E N D A T I O N S  
Power wheelchairs provide mobility and independence for hundreds of 
thousands of Medicare beneficiaries.  In 2005 and 2006, CMS revised 
power wheelchair documentation requirements in response to numerous 
instances of fraud and abuse and the growth in Medicare power 
wheelchair expenditures.  Power wheelchair suppliers must maintain 
specific documentation to support beneficiaries need for the provided 
power wheelchairs.  Medicare policy requires that suppliers and 
prescribing physicians coordinate to ensure that beneficiaries receive 
the most appropriate equipment to accommodate their mobility needs.   
We found that 60 percent of claims for standard and complex 
rehabilitation power wheelchairs that beneficiaries received in the first 
half of 2007 did not meet Medicare documentation requirements.  These 
claims accounted for $112 million in improper Medicare payments, out 
of the $189 million total allowed by Medicare during the 6-month 
period.  Beneficiaries were responsible for paying $22 million of this 
amount.   
Power wheelchair claims were more likely to meet some documentation 
requirements than others.  Two out of five power wheelchair claims had 
multiple errors.  In addition, suppliers submitted incomplete documents 
almost three times as often as they failed to submit required documents.  
The specialty evaluation report was one of the documents most often not 
submitted by complex rehabilitation power wheelchair suppliers. 
We found that complex rehabilitation power wheelchair claims had a 
higher documentation error rate than standard power wheelchair 
claims.  Standard power wheelchair claims submitted by low-volume 
suppliers had a higher documentation error rate than those from      
high-volume suppliers.   
Based on these findings, we recommend that CMS: 
Improve compliance with Medicares power wheelchair 
documentation requirements 
CMS should consider the following methods for improving compliance:  
  Conduct additional reviews of power wheelchair claims.  When 
determining the additional claims to review, CMS should 
consider that complex rehabilitation power wheelchair claims 
had a higher documentation error rate than standard power 
wheelchair claims.  In addition, standard power wheelchair 
claims submitted by low-volume suppliers had a higher 
documentation error rate than those from high-volume suppliers.     
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  23   
   
R E C O M M E N D A T I O N S  
  Recover overpayments from suppliers that do not meet 
documentation requirements and consider further action as 
appropriate.  Suppliers are liable for overpayments when they do 
not submit documentation to substantiate services billed to the 
program.  CMS should deny claims identified during                
prepayment reviews that do not meet documentation 
requirements and recover overpayments for claims identified 
during postpayment reviews.  CMS should also consider 
investigating suppliers that do not meet documentation 
requirements.     
  Increase education for suppliers and prescribing physicians about 
documentation requirements.  While suppliers are ultimately 
responsible for claims they submit, Medicare requires that 
suppliers obtain documents and receive approval from the 
prescribing physicians.  Therefore, CMS should consider 
physicians awareness of power wheelchair documentation 
requirements.   
Take appropriate action on sampled claims found to be in error 
We will forward detailed information on these claims to CMS in a 
separate transmittal.   
AGENCY COMMENTS AND OFFICE OF INSPECTOR GENERAL 
RESPONSE 
CMS concurred with both of our recommendations.  CMS noted that it 
has multiple efforts underway or planned that align with each 
suggested method to improve compliance with Medicares power 
wheelchair documentation requirements.  For example, CMS recently 
awarded a contract that will involve the review of power wheelchair 
claims submitted by certain suppliers.  Additionally, CMS will instruct 
DME Medicare Administrative Contractors to determine whether 
required documentation is present, in addition to determining whether 
beneficiaries are receiving medically necessary power wheelchairs.  
Further, CMS stated that it will take appropriate action to recover 
overpayments from suppliers for claims that do not meet documentation 
and policy requirements or clinical criteria.  CMS also stated that it 
continues to develop educational materials for suppliers and prescribing 
providers and expects to disseminate additional information on power 
wheelchair documentation requirements to both of these groups through 
open-door forums and calls.  Finally, CMS will forward the sampled 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  24   
   
R E C O M M E N D A T I O N S  
claims we found to be in error to the appropriate contractors to identify 
and recover overpayments.  We will forward information on these claims 
to CMS under separate cover.   
We did not make changes to the report based on CMS comments.  The 
full text of CMSs comments appears in Appendix E.   
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  25   
   
 A P P E N D I X ~ A  
 
Medicares Power Wheelchair Documentation Requirements  
Document  Description  Requirements  
Prescription  Physicians order for a power    Supplier must maintain on file 
wheelchair    The prescription must include: 
-  beneficiary name 
-  beneficiary examination date 
-  diagnoses and conditions that support the claim 
-  item description 
-  expected length of time the beneficiary will need the chair 
-  prescribing physicians signature 
-  prescription date  
  45-day requirement 
-  supplier must have documentation of the date the supplier received the prescription from the 
physician 
-  prescription must be received by the supplier within 45 days after the beneficiarys 
examination and before the chairs delivery 
Supporting  Documentation that will    Supplier must maintain on file 
documentation  include pertinent parts of the    Must include beneficiary medical records, such as physicians notes from the beneficiarys 
beneficiarys medical record  examination; forms and attestations are inadequate 
that support the medical    45-day requirement 
necessity for the power 
-  supplier must have documentation of the date the supplier received the supporting 
wheelchair 
documentation from the physician 
-  supporting documentation must be received by the supplier within 45 days after the 
beneficiarys examination and before the chairs delivery 
 
NOT INCLUDED IN REVIEW: 
  Must support the medical necessity of the power wheelchair 
  Notes from the beneficiary examination must indicate that the reason for the visit was a mobility 
examination 
Specialty  Written report of the     Supplier must maintain on file 
evaluation  evaluation by physical or   
report*  occupational therapist or  NOT INCLUDED IN REVIEW: 
physician justifying the need 
  Must support the medical necessity of the power wheelchair and all options and accessories 
for the power wheelchair and 
  Specialty evaluation must be performed by a medical professional with experience in complex 
all accessories 
rehabilitation power wheelchair evaluations 
Detailed  Document showing items that    Supplier must maintain on file 
product  will be billed to Medicare    Must include for all billed items (power wheelchair and any accessories or power options): 
description  and/or beneficiary 
- procedure code(s) of all billed items 
- item description(s) 
- Medicare fee schedule amount(s) 
- supplier charge(s) 
  Supplier must have documentation of date the supplier received the detailed product description 
from physician 
  Supplier must receive detailed product description before chairs delivery 
  Must include prescribing physicians signature and date of physicians signature 
Home  Written report documenting    Supplier must maintain on file 
assessment  the suppliers assessment of    Assessment must have occurred before or during the chairs delivery 
report  the beneficiarys home    Assessment must address the physical layout of the home 
environment  
 
Proof of  Documentation showing the    Supplier must maintain on file 
delivery  power wheelchair was   
delivered to the beneficiary 
* Applies only to complex rehabilitation power wheelchairs. 
Source:  Medicare Power Mobility Device Local Coverage Determination. 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  26   
   
 A P P E N D I X ~ B  
 
Population and Sample Sizes by Stratum, First Half of 2007 
Population  Sample 
 Stratum  Definition  Claims  Expenditures  Suppliers  Claims  Expenditures  Suppliers 
Standard power wheelchair claims  
1  by low-volume suppliers  7,223  $28,949,132  2,352  125  $499,152  124 
Standard power wheelchair claims 
2  by high-volume suppliers  35,910  $144,354,060  716  125  $502,989  94 
All standard power wheelchair 
1 and 2  claims   43,133 $173,303,192  3,068  250  $1,002,141  218 
Complex rehabilitation power 
3  wheelchair claims*  3,001  $16,010,906  1,064  125  $665,200  113 
      Total  46,134 $189,314,098  3,362**  375  $1,667,341  325** 
* Procedure codes K0835K0864. 
** Suppliers figures do not sum to totals because of overlap (some suppliers in our sample provided both standard and complex rehabilitation power wheelchairs).    
Source:  Office of Inspector General analysis of Medicare power wheelchair claims with dates of service from January 1 to June 30, 2007. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 A P P E N D I X ~ C  
 
Incomplete Documentation Error Rates, First Half of 2007 
Document  Incomplete Documentation Error Description   Error Rate
Supporting  Did not include physicians notes from medical record  20.4% 
documentation 
No documentation of date supplier received supporting documentation   9.9% 
Included documentation of the date the supplier received the supporting 
documentation, but the supplier did not receive the supporting documentation 
within 45 days after the beneficiary examination  9.1% 
Included documentation of the date the supplier received the supporting 
documentation, but the supplier did not receive the supporting documentation  
before the delivery date  8.1% 
Overlapping errors  (9.2%) 
     Total incomplete documentation  38.3% 
Detailed product  Did not include all required information for all billed items   17.1% 
description 
No physician signature  0.4% 
No date of physician signature  0.8% 
No documentation of the date the supplier received the detailed product 
description from the physician  8.4% 
Included documentation of the date the supplier received the detailed product 
description, but the supplier did not receive the detailed product description 
before the delivery date  5.4% 
Overlapping errors  (6.0%) 
     Total incomplete documentation  26.1% 
Prescription  One or more required elements missing  15.9% 
No documentation of the date the supplier received the prescription   9.1% 
Included documentation of the date the supplier received the prescription, but 
the supplier did not receive the prescription within 45 days after the beneficiary 
examination  5.5% 
Included documentation of the date the supplier received the prescription, but 
the supplier did not receive the prescription before the delivery date  5.9% 
Overlapping errors  (5.6%) 
     Total incomplete documentation  30.8% 
Home assessment  Home assessment was conducted after chairs delivery  6.9% 
report 
Home assessment report did not address the physical layout of the 
beneficiarys home  2.5% 
Overlapping errors  (1.0%) 
     Total incomplete documentation  8.4% 
Note:  Overlapping errors are subtracted to obtain the total. 
Source:  Office of Inspector General analysis of supplier documentation, 2009. 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  28   
   
 AAP PP PE EN ND DI XI X  C~  D  
A P P E N D I X   D  
 
Estimates and Confidence Intervals:  Medicare Documentation Error Rates for Standard and 
Complex Rehabilitation Power Wheelchair Claims, First Half of 2007 
95-Percent Confidence 
Estimate Description  Sample Size  Point Estimate Interval 
All Power Wheelchairs 
Supporting documentation  365  40.3%  33.6%47.3% 
Detailed product description  365  39.7%  33.1%46.7% 
Prescription  365  32.1%  26.0%38.9% 
Specialty evaluation report**  365  2.0%  1.5%2.6% 
Home assessment report  365  18.2%  13.4%24.3% 
Proof of delivery  365  1.2%  0.4%3.7% 
Overlapping errors  365  (73.1%)  (58.8%87.4%) 
     Total errors  365  60.4%  53.2%67.2% 
Standard Power Wheelchairs:  All Suppliers 
Supporting documentation  241  38.8%  31.7%46.3% 
Detailed product description  241  38.2%  31.2%45.8% 
Prescription  241  30.2%  23.8%37.6% 
Home assessment report  241  17.5%  12.5%24.1% 
Proof of delivery  241  1.2%  0.4%4.0% 
Overlapping errors  241  (67.8%)  (52.6%83.2%) 
     Total errors  241  58.1%  50.4%65.4% 
Complex Rehabilitation Power Wheelchairs 
Supporting documentation  124  61.3%  52.5%69.4% 
Detailed product description  124  60.5%  51.7%68.6% 
Prescription  124  58.1%  49.3%66.4% 
Specialty evaluation report**  124  29.8%  22.5%38.4% 
Home assessment report  124  28.2%  21.1%36.7% 
Proof of delivery  124  0.8%  0.1%5.4% 
Overlapping errors  124  (146.0%)  (124.2%167.8%) 
     Total errors  124  92.7%  86.7%96.2% 
** Requirement does not apply to standard power wheelchairs. 
Note:  Overlapping errors are subtracted to obtain the total. 
Source:  Office of Inspector General (OIG) analysis of supplier documentation, 2009. 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  29   
   
A P P E N D I X   D  
 
 
Estimates and Confidence Intervals:  Medicare Documentation Error Rates for Low- and 
High-Volume Standard Power Wheelchair Claims, First Half of 2007 
95-Percent Confidence 
Estimate Description  Sample Size  Point Estimate Interval 
Standard Power Wheelchairs:  Low-Volume Suppliers 
Supporting documentation  120  50.8%  41.9%59.7% 
Detailed product description  120  47.5%  38.7%56.5% 
Prescription  120  36.7%  28.5%45.7% 
Home assessment report  120  18.3%  12.4%26.3% 
Proof of delivery  120  3.3%  1.2%8.6% 
Overlapping errors  120  (85.0%)  (64.3%105.7%) 
     Total errors  120  71.7%  62.9%79.0% 
Standard Power Wheelchairs:  High-Volume Suppliers 
Supporting documentation  121  36.4%  28.2%45.4% 
Detailed product description  121  36.4%  28.2%45.4% 
Prescription  121  28.9%  21.5%37.7% 
Home assessment report  121  17.4%  11.5%25.3% 
Proof of delivery  121  0.8%  0.1%5.8% 
Overlapping errors  121  (64.5%)  (46.5%82.4%) 
     Total errors  121  55.4%  46.3%64.1% 
Note:  Overlapping errors are subtracted to obtain the total. 
Source:  OIG analysis of supplier documentation, 2009. 
 
 
 
 
 
 
 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  30   
   
A P P E N D I X   D  
 
Estimates and Confidence Intervals:  Improper Payments for Power Wheelchair Claims With 
Documentation Errors, First Half of 2007 
Estimate Description  Sample Size  Point Estimate 95-Percent Confidence Interval 
All Power Wheelchairs 
Supporting documentation  365  $74,702,894  $62,297,706$87,108,083 
Detailed product description  365  $73,530,908  $61,136,655$85,925,162 
Prescription  365  $59,769,646  $48,047,256$71,492,036 
Specialty evaluation report**  365  $4,695,238  $3,422,965$5,967,511 
Home assessment report  365  $33,971,678  $24,166,707$43,776,648 
Overlapping improper payments  365  ($136,894,371)  ($110,972,878$162,815,864) 
Total improper payments*  365  $111,962,318  $99,272,522$124,652,115 
Beneficiarys copayment  365  $21,742,270  $19,194,534$24,290,011 
Complex Rehabilitation Power Wheelchairs 
Total improper payments  124 $14,704,007  $13,883,853$15,524,161 
Standard Power Wheelchairs:  All Suppliers 
Total improper payments  241  $97,258,311  $84,572,801$109,943,821 
Standard Power Wheelchairs:  Low-Volume Suppliers 
Total improper payments  120 $19,803,457  $17,550,837$22,056,078 
Standard Power Wheelchairs:  High-Volume Suppliers 
Total improper payments  121 $77,454,854  $64,905,544$90,004,163 
* We do not report improper payments by Medicare and its beneficiaries for claims that did not have proof of delivery because the confidence 
intervals contain zero.  Therefore, improper payments do not add to the total.   
** Requirement does not apply to standard power wheelchairs. 
Note:  Overlapping errors are subtracted to obtain the total. 
Source:  OIG analysis of supplier documentation, 2009. 
 
 
 
 
 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  31   
   
A P P E N D I X   D  
 
Estimates and Confidence Intervals:  Number of Medicare Documentation Errors per Power Wheelchair 
Claim, First Half of 2007 
Sample  Point  95-Percent Confidence 
Estimate Description   Size  Estimate  Interval 
Percentage of claims that met all Medicare documentation requirements  365   39.6%   32.8%46.8% 
Percentage of claims with one document that did not meet all Medicare 
documentation requirements  365  22.2%   16.9%28.5% 
Percentage of claims with two documents that did not meet all Medicare 
documentation requirements  365  13.4%  9.3%18.8% 
Percentage of claims with three documents that did not meet all Medicare 
documentation requirements  365  16.4%  11.8%22.3% 
Percentage of claims with more than three documents that did not meet 
all Medicare documentation requirements  365  8.5%  5.5%12.9% 
Percentage of claims with multiple Medicare documentation errors  365   38.2%   31.7%45.2% 
Improper payments for claims with one document that did not meet all 
Medicare documentation requirements  365  $40,682,641  $30,244,946$51,120,336 
Improper payments for claims with two documents that did not meet all 
Medicare documentation requirements  365  $24,873,263  $16,351,987$33,394,540 
Improper payments for claims with three documents that did not meet all 
Medicare documentation requirements  365  $30,048,940  $20,676,710$39,421,170 
Improper payments for claims with more than three documents that did 
not meet all Medicare documentation requirements  365  $16,357,474  $9,760,665$22,954,282 
Improper payments for claims with multiple Medicare documentation 
errors  365  $71,279,677  $59,005,460$83,553,895 
Source:  OIG analysis of supplier documentation, 2009. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  32   
   
A P P E N D I X   D  
 
 
Estimates and Confidence Intervals:  Not Submitted and Incomplete Medicare Documentation 
Error Rates for Power Wheelchair Claims, First Half of 2007 
95-Percent 
Estimate Description  Sample Size  Point Estimate Confidence Interval 
Supporting Documentation 
Document not submitted  365  2.0 %  0.8%5.0% 
Incomplete documentation  365  38.3%  31.7%45.3% 
     Total errors  365 40.3%  33.6%47.3% 
Detailed Product Description 
Document not submitted  365  13.6%  9.7%18.7% 
Incomplete documentation  365  26.1%  20.4%32.8% 
     Total errors  365  39.7%  33.1%46.7% 
Prescription 
Document not submitted  365  1.3%  0.8%2.2% 
Incomplete documentation  365  30.8%  24.7%37.6% 
     Total errors  365 32.1%  26.0%38.9% 
Home Assessment Report 
Document not submitted  365  9.9%  6.4%14.8% 
Incomplete documentation  365 8.4%  5.2%13.2% 
     Total errors  365  18.2%  13.4%24.3% 
Specialty Evaluation Report 
Complex rehabilitation power wheelchair claims for 
which the supplier did not submit a specialty evaluation 
report  124  29.8%  22.5%38.4% 
All power wheelchair claims for which the supplier did 
not submit a specialty evaluation report  365  2.0%  1.5%2.6% 
Proof of Delivery 
Document not submitted  365  1.2%  0.4%3.7% 
All Documents 
At least one document not submitted  365  19.9%  15.1%25.6% 
At least one document incomplete  365  56.5%  49.3%63.4% 
Overlapping errors  365  (15.9%)  (11.1%20.7%) 
     Total errors  365  60.4%  53.2%67.2% 
Ratio of claims with incomplete document(s) to claims 
with document(s) not submitted   365  2.84  2.093.60 
Source:   OIG analysis of supplier documentation, 2009. 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  33   
   
A P P E N D I X   D  
 
 
 
 
Estimates and Confidence Intervals:  Comparisons of Medicare Documentation Error Rates by Wheelchair 
Type and Supplier Volume, First Half of 2007  
95-Percent 
Sample  Point  Confidence 
Estimate Description  Size  Estimate  Interval  P-Value 
Comparisons by Wheelchair Type 
Difference in percentage of power wheelchairs for which the supplier did 
not submit complete supporting documentation  365  22.5%  11.3%33.7%  0.0001 
Difference in percentage of power wheelchairs for which the supplier did 
not submit a complete detailed product description  365 22.3%  11.0%33.5%  0.0001 
Difference in percentage of power wheelchairs for which the supplier did  
not submit a complete prescription  365 27.9%  16.8%38.9%  <0.0001 
Difference in percentage of power wheelchairs for which the supplier did  
not submit a complete home assessment report  365 10.7%  1.0%20.4%  0.0309 
Difference in percentage of power wheelchairs for which the supplier did  
not submit one or more complete documents  365 34.7%  25.9%43.4%  <0.0001 
Comparisons by Supplier Volume 
Difference in percentage of standard power wheelchairs for which the 
supplier did not submit complete supporting documentation  241 14.5%  2.0%26.9%  0.0228 
Difference in percentage of standard power wheelchairs for which the 
supplier did not submit one or more complete documents  241 16.3%  4.3%28.3%  0.0082 
Source:   OIG analysis of supplier documentation, 2009. 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  34   
   
A P P E N D I X   D  
 
 
 
Estimates and Confidence Intervals:  Incomplete Medicare Documentation Error Rates, First Half of 2007 
Sample  Point  95-Percent 
Estimate Description  Size  Estimate  Confidence Interval 
Supporting Documentation 
Did not include physicians notes from medical record  365 20.4%  15.6%26.1% 
No documentation of date supplier received supporting documentation   365 9.9%  6.5%14.9% 
Included documentation of the date the supplier received the supporting 
documentation, but the supplier did not receive the supporting documentation within    
45 days after the beneficiary examination  365  9.1%  5.8%13.9% 
Included documentation of the date the supplier received the supporting 
documentation, but the supplier did not receive the supporting documentation before 
the delivery date  365  8.1%  4.9%13.2% 
Overlapping errors  365  (9.2%)  (5.0%13.4%) 
     Total incomplete documentation  365  38.3%  31.7%45.3% 
Median number of days for supplier receipt of supporting documentation after 
beneficiary examination   365 6.8  5.010.9 
Detailed Product Description 
Did not include all required information for all billed items   365  17.1%  12.5%22.9% 
No physician signature  365 0.4%  0.2%1.2% 
No date of physician signature  365 0.8%  0.4%1.6% 
No documentation of the date the supplier received the detailed product description 
from the physician  365  8.4%  5.2%13.3% 
Claim included documentation of the date the supplier received the detailed product 
description but the supplier did not receive the detailed product description before the 
delivery date  365  5.4%  2.9%9.8% 
Overlapping errors  365  (6.0%)  (2.9%9.1%) 
     Total incomplete documentation  365  26.1%  20.4%32.8% 
Prescription 
One or more required elements missing  365  15.9%  11.6%21.4% 
No documentation of the date the supplier received prescription   365 9.1%  5.7%14.1% 
Included documentation of the date the supplier received the prescription, but the 
supplier did not receive the prescription within 45 days after the beneficiary 
examination  365  5.5%  3.1%9.5% 
Included documentation of the date the supplier received the prescription, but the 
supplier did not receive the prescription before the delivery date  365  5.9%  3.3%10.3% 
Overlapping errors  365  (5.6%)  (2.6%8.5%) 
     Total incomplete documentation  365  30.8%  24.7%37.6% 
Median number of days for supplier receipt of prescription after beneficiary examination  365  6.6  4.612.0 
Note:  Overlapping errors are subtracted to obtain the total. 
Source:   OIG analysis of supplier documentation, 2009. 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  35   
   
A P P E N D I X   D  
 
 
 
Estimates and Confidence Intervals:  Incomplete Medicare Documentation Error Rates, First Half of 2007 
(continued) 
Sample  Point  95-Percent 
Estimate Description  Size  Estimate  Confidence Interval 
Home Assessment Report 
Home assessment was conducted after chairs delivery  365  6.9%  4.0%11.7% 
Home assessment report did not address the physical layout of the beneficiarys home  365  2.5%  1.2%5.2% 
Overlapping errors  365  (1.0%)  (0.0%2.3%) 
     Total incomplete documentation  365  8.4%  5.2%13.2% 
Note:  Overlapping errors are subtracted to obtain the total. 
Source:   OIG analysis of supplier documentation, 2009. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  36  A  P  PEN  0  x  E 

l4 
..
.. ,,,,
,,~ 
DEPARTMENT OF HEALTH & HUMAN SERVICES  Centers for Medicare & Medicaid Services 
Administrator 
Washington, DC 20201 
NOV  1 9 2009 
DATE: 
TO:  Daniel R. Levinson 
Inspector General 
FROM:  -Charlene Frizzera 
Acting Administrator 
SUBJECT:  Office ofInspector General (OIG) Draft Report: "Medicare Power Wheelchair 
Claims Frequently Did Not Meet Documentation Requirements"  . 
(OEI-04-07-00401) 
Thank you for the opportunity to review and comment on the OIG's draft report, "Medicare 
Power Wheelchair Claims Frequently Did Not Meet Documentation Requirements." The 
Centers for Medicare & Medicaid Services (CMS) appreciates the time and resources the OIG 
has invested to determine the extent to which standard and complex rehabilitation power 
wheelchair claims met Medicare documentation requirements. 
The CMS requires suppliers to maintain specific documentation that supports the beneficiary's 
need for a power mobility device. The OIG found that 60 percent of claims for standard and 
complex rehabilitation power wheelchairs did not meet all Medicare documentation 
requirements. These claims accounted for $112 million in improper payments.  The OIG also 
found complex rehabilitation wheelchairs had a higher documentation error rate than standard 
power wheelchair claims. 
The CMS recognizes the complexity of power wheelchair claims and is committed to continually 
reviewing and refining its processes to reduce improper payments. We are also committed to 
ensuring that Medicare contractors follow and apply our policies and documentation 
requirements while reviewing claims. 
The OIG made the following recommendations. 
OIG Recommendation 
Improve compliance with Medicare'~ power wheelchair documentation requirements. 
Conduct additional reviews ofpower wheelchair claims. 
OEI040700401  MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  37   
   
A P P E N D I X   E  
 
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A P P E N D I X   E  
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  39   
   
A P P E N D I X   E  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  40   
   
A P P E N D I X   E  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  41   
   
 A C K N O W L E D G M E N T S  
 
This report was prepared under the direction of Dwayne F. Grant, 
Regional Inspector General for Evaluation and Inspections in the 
Atlanta regional office.   
Sarah Ambrose and Mina Zadeh served as team leaders for this study.   
Other principal Office of Evaluation and Inspections staff from the 
Atlanta regional office who contributed to this report include Peggy 
Daniel.  Berivan Demir, Kevin Farber, and Scott Manley from the 
central office; Carolyn Kenline from the Boston regional office; and 
Robert A. Vito from the Philadelphia office also contributed.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
OEI-04-07-00401     MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS  42