Department of Health & Human Services 
OFFICE OF 
 
INSPECTOR GENERAL 
 
 
 
 
 
 
 
M P W
OST    OWER  HEELCHAIRS IN 
 
M P D
THE  EDICARE  ROGRAM  ID 
 
 
N M M N
OT  EET  EDICAL  ECESSITY 
 
  G  
UIDELINES
 
 
 
 
 
Daniel R. Levinson  
Inspector General 
 
July 2011 
OEI-04-09-00260   
   
 E X E C U T I V E   S U M M A R Y  
OBJECTIVES
 
1.  To determine the extent to which standard power wheelchairs and 
complex rehabilitation power wheelchairs provided to Medicare 
beneficiaries during the first half of 2007 were medically necessary 
based on records from suppliers. 
2.  To determine whether records from physicians who prescribed 
power wheelchairs supported the medical necessity of power 
wheelchairs as documented by suppliers. 
BACKGROUND 
From 1999 to 2003, Medicare payments for power wheelchairs increased 
approximately 350 percent, from $259 million to $1.2 billion annually, 
raising concerns about inappropriate Medicare payments.  In response, 
in 2005 and 2006 the Centers for Medicare & Medicaid Services (CMS) 
revised its policies related to power wheelchair coverage and coding.  
After these changes, Medicares annual payments for power wheelchairs 
decreased to a relative low of $658 million in 2007.  However, 
expenditures rose to $779 million in 2008 and $723 million in 2009. 
Beneficiaries are eligible to receive power wheelchairs under Medicare 
Part B coverage of durable medical equipment (DME).  Beneficiaries 
who are prescribed power wheelchairs receive them from suppliers, 
which bill Medicare for reimbursement.  Before providing a power 
wheelchair, a supplier receives from a prescribing physician a 
prescription for the power wheelchair and documentation from the 
beneficiarys medical record to support the medical necessity of a power 
wheelchair. 
We selected a sample of 375 claims for standard and complex 
rehabilitation power wheelchairs supplied to beneficiaries in the first 
half of 2007 and conducted a medical record review.  Based on suppliers 
records, reviewers determined whether each claim was medically 
necessary and supported by sufficient documentation.  They also 
reviewed records from prescribing physicians.  For claims without errors 
based on suppliers records, reviewers determined whether the 
prescribing physicians records supported the suppliers power 
wheelchair claims.   
 
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E X E C U T I V E   S U M M A R Y  
FINDINGS 
Sixty-one percent of power wheelchairs provided to Medicare 
beneficiaries in the first half of 2007 were medically unnecessary or 
had claims that lacked sufficient documentation to determine 
medical necessity.  Based on records submitted by suppliers that 
provided power wheelchairs, 9 percent of power wheelchairs were 
medically unnecessary and another 52 percent had claims that were 
insufficiently documented to determine whether the power wheelchairs 
were medically necessary.  Of the $189 million that Medicare allowed 
for power wheelchairs provided in the first half of 2007, $95 million was 
for power wheelchairs that were medically unnecessary or had claims 
that were insufficiently documented.  Beneficiaries who received 
medically unnecessary power wheelchairs needed a less expensive type 
of equipment or a different type of power wheelchair.  For 2 percent of 
claims, a less expensive type of equipment (e.g., a scooter or a manual 
wheelchair) should have been provided.  For the remaining 7 percent of 
claims, the beneficiaries should have received a different type of power 
wheelchair than was provided.   
Medical necessity and documentation errors varied by power 
wheelchair type.  Claims for standard and complex rehabilitation 
power wheelchairs had similar overall error rates (61 and 56 percent, 
respectively).  However, standard power wheelchairs were less likely to 
be medically unnecessary than complex rehabilitation power 
wheelchairs (8 and 24 percent, respectively).  Conversely, claims for 
standard power wheelchairs were more likely to have insufficient 
documentation than claims for complex rehabilitation power 
wheelchairs (53 and 32 percent, respectively).  Because standard power 
wheelchairs accounted for most of Medicares power wheelchair 
expenditures, errors among claims for such wheelchairs resulted in 
higher inappropriate payments than did errors among claims for 
complex rehabilitation power wheelchairs ($90 million and $5 million, 
respectively). 
Prescribing physicians records do not support the medical necessity 
of most power wheelchairs.  Seventy-eight percent of claims without 
supplier-record errors were not supported by records provided by 
physicians who prescribed the power wheelchairs.  That is, while 
suppliers records indicated that power wheelchairs were medically 
necessary, physicians records indicated that they were medically 
unnecessary, or physicians records provided insufficient documentation or 
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E X E C U T I V E   S U M M A R Y  
no documentation of medical necessity.  In most cases, physicians records 
had insufficient documentation to support the medical necessity of power 
wheelchairs.  Less often, physicians records contradicted suppliers 
records. 
RECOMMENDATIONS 
Our review found that power wheelchairs paid for by Medicare are not 
always medically necessary and that claims for power wheelchairs 
frequently have insufficient documentation to support medical 
necessity.  We found that of the $189 million that Medicare allowed for 
power wheelchairs provided in the first half of 2007, $95 million was for 
power wheelchairs that were medically unnecessary or had claims that 
were insufficiently documented.  Although CMS has taken steps since 
2007 to decrease errors among suppliers of power wheelchairs and other 
DME, Medicare has paid significantly more in recent years for power 
wheelchairs than it did in 2007.  These increases may indicate that 
CMS continues to pay for power wheelchairs that are not medically 
necessary and/or that have claims that do not meet documentation 
requirements.   
Two previous OIG reports based on the same sample of power 
wheelchairs found problems with coding and with documentation 
requirements.  This report shows additional problems with suppliers 
compliance with Medicare requirements.  Across all three reports, 
80 percent of claims for power wheelchairs supplied to beneficiaries in 
the first half of 2007 did not meet Medicare requirements.  Additionally, 
OIG has issued previous reports identifying substantial vulnerabilities 
in the Medicare Durable Medical Equipment, Prosthetics, Orthotics, 
and Supplies (DMEPOS) benefit.   
Based on our findings and prior work, we recommend that CMS: 
Enhance reenrollment screening standards for current DMEPOS 
suppliers.  Federal regulations place new DMEPOS suppliers at a risk 
level of high, whereas currently enrolled DMEPOS suppliers are placed 
at a risk level of moderate.  We believe that currently enrolled DMEPOS 
suppliers should be subject to the same enrollment screening standards as 
newly enrolling DMEPOS suppliers and should also be placed at the risk 
level of high. 
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E X E C U T I V E   S U M M A R Y  
Review records from sources in addition to the supplier, such as the 
prescribing physician, to determine whether power wheelchairs are 
medically necessary.  CMS should direct its contractors to review records 
from prescribing physicians, in addition to those from suppliers.   
Continue to educate power wheelchair suppliers and prescribing 
physicians to ensure compliance with clinical coverage criteria.  In 
2009, CMS began requiring that suppliers meet quality standards to be 
accredited.  Additionally, in recent years CMS has developed a variety of 
educational materials for power wheelchair suppliers and prescribing 
physicians.  However, our results indicate that CMS should continue to 
educate, and promote collaboration between, suppliers and physicians to 
ensure that beneficiaries receive medically necessary power wheelchairs 
that are appropriate for their mobility needs.  We suggest that CMS focus 
its educational efforts for suppliers and prescribing physicians on the 
following topics: 
  requirements for determining and documenting the medical 
necessity of a power wheelchair,   
  requirements for determining the most appropriate power 
wheelchair for a beneficiary, and   
  collaboration between supplier and physician to determine the 
most appropriate power wheelchair for a beneficiary.   
Review suppliers of sampled claims we found to be in error. 
AGENCY COMMENTS AND OFFICE OF INSPECTOR GENERAL 
RESPONSE 
CMS concurred with the second, third, and fourth recommendations.  
CMS did not concur with the first recommendation.  In response to the 
first recommendation, CMS noted that it has in place other tools that 
allow for increased scrutiny of some current suppliers.  Based on this 
reports findings, which reinforce the findings of multiple OIG reports in 
recent years identifying substantial vulnerabilities in the Medicare 
DMEPOS benefit, we maintain that all current DMEPOS suppliers 
should be subject upon reenrollment to the screening standards for the 
risk level of high.  
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 T A B L E   O F   C O N T E N T S  
 
  EX ECUT I VE  SUM M ARY  .....................................i 
   
   
  I NT RO DU CT I O N  ............................................ 1 
 
 
 
 
 
F I NDI NG S  .................................................  19 
 
  Sixty-one percent of power wheelchairs provided to  
 
Medicare beneficiaries in the first half of 2007 were medically  
 
unnecessary or had claims that lacked sufficient documentation 
 
to determine medical necessity   ...........................  19 
 
    Medical necessity and documentation errors  
    varied by power wheelchair type ...........................  22 
 
  Prescribing physicians records do not support the 
 
  medical necessity of most power wheelchairs .................  25 
 
   
 
  RECO M M END AT I O N S  .....................................  28 
 
  Agency Comments and Office of Inspector General Response ....  31 
 
 
   
APP EN DI X ES  .............................................  32 
    A:  Clinical Coverage Criteria for Selected  
        Power Wheelchairs...................................  32 
    
  B:  Clinical Coverage Criteria for Selected Power 
Wheelchair Power Options and Accessories ...............  36 
 
  C:  Population and Sample Sizes by Stratum, First Half 
        of 2007 ............................................  39 
     
  D:  Estimates and Confidence Intervals .....................  40 
 
  E:  Agency Comments ...................................  44 
   
ACKNO WL E DG M E N T S ..................................... 48 
 
 
OEI-04-09-00260    MOST MEDICARE POWER WHEELCHAIRS DID NOT MEET MEDICAL NECESSITY GUIDELINES     
   
 I N T R O D U C T I O N  
OBJECTIVES 
1.  To determine the extent to which standard power wheelchairs and 
complex rehabilitation power wheelchairs provided to Medicare 
beneficiaries during the first half of 2007 were medically necessary 
based on records from suppliers. 
2.  To determine whether records from physicians who prescribed 
power wheelchairs supported the medical necessity of power 
wheelchairs as documented by suppliers. 
BACKGROUND 
From 1999 to 2003, Medicare payments for power wheelchairs increased 
approximately 350 percent, from $259 million to $1.2 billion annually, 
while overall Medicare program expenditures rose 28 percent.1, 2  This 
increase caused concern within the Office of Inspector General (OIG), 
Government Accountability Office (GAO), and Centers for Medicare & 
Medicaid Services (CMS) about inappropriate Medicare payments.3  In 
response, CMS revised in 2005 and 2006 its Medicare policies related to 
power wheelchair coverage and coding.4  After these changes, 
Medicares annual payments for power wheelchairs decreased to a 
relative low of $658 million in 2007.  However, expenditures rose to 
$779 million in 2008 and $723 million in 2009. 
Beneficiaries are eligible to receive power wheelchairs under Medicare 
Part B coverage of durable medical equipment (DME).5  Most 
beneficiaries who require power wheelchairs are unable to walk and 
 
1 Medicare payments refers to the total Medicare-allowed amounts.  Medicare pays 
80 percent of the fee schedule amount, and the Medicare beneficiary is responsible for 
paying the remaining 20 percent. 
2 71 Fed. Reg. 17021, 17022 (Apr. 5, 2006).   
3 For example, Department of Health & Human Services (HHS) OIG, Medicare Payments 
for Power Wheelchairs, OEI-03-02-00600, April 2004; GAO, CMSs Program Safeguards Did 
Not Deter Growth in Spending for Power Wheelchairs, GAO-05-43, November 2004; and 
CMS and OIG, New Efforts Aimed at Stopping Abuse of the Power Wheelchair Benefit in 
the Medicare Program, September 9, 2003, accessed at 
http://oig.hhs.gov/publications/docs/press/2003/090903release.pdf on October 25, 2010.  
4 CMS, Pub. No. 11272P, 2006 Fee Schedule Amounts for Power Mobility Devices Have 
 
Been Refined, November 2006.
5 42 CFR  410.38. 
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have severe upper body weakness.6  Beneficiaries who are prescribed 
power wheelchairs by their physicians receive them from DME 
suppliers, which bill Medicare for reimbursement.  Prior to January 1, 
2011, the beneficiary was able to choose to rent or purchase the power 
wheelchair.7  Almost all beneficiaries chose to purchase their power 
wheelchairs.8 
Power Wheelchair Types 
Medicare covers more than 650 models of power wheelchairs.9  Each 
model is assigned to 1 of 42 power wheelchair HCPCS codes.10  The 
HCPCS code assignment is based on the models performance, weight 
capacity, seat type, portability, and power seating system capability.11   
In the first half of 2007, two types of power wheelchairsstandard and 
complex rehabilitationaccounted for over 80 percent of all Medicare 
expenditures for power wheelchairs.12, 13  These two types are covered 
by Medicare under 27 HCPCS codes that include nearly 400 power 
wheelchair models.14 
 
6 CMSs Medicare Learning Network, Medicare Coverage of Power Mobility Devices:  
Power Wheelchairs and Power Operated Vehicles, April 2006. 
7 Effective for items furnished on or after January 1, 2011, section 3136(a)(2) of the 
Affordable Care Act (ACA) eliminated the lump-sum (up-front) purchase option for standard 
power wheelchairs.  Medicare pays for a maximum of 13 continuous months of rental, and 
the supplier must transfer ownership to the beneficiary after the 13th month.  For complex 
rehabilitation power wheelchairs, payment can continue to be made on a lump-sum 
purchase basis or monthly rental basis. 
8 In the first half of 2007, new power wheelchair purchases accounted for 95 percent of 
Medicare power wheelchair expenditures.  OIG analysis of claims from the National Claims 
History file submitted under Healthcare Common Procedure Coding System (HCPCS) codes 
K0823K0864 with dates of service from January 1 to June 30, 2007.   
9 Medicare Pricing, Data Analysis, and Coding (PDAC) contractor, Motorized Wheelchair 
Product Classification List, April 21, 2010.   
10 Power wheelchair HCPCS codes are K0813K0864.  Within that range, Medicare has 
not assigned power wheelchairs to the HCPCS codes K0817K0819, K0832K0834, and 
K0844K0847. 
11 Medicare PDAC contractor, Power Mobility Device Coding Guidelines.  Accessed at 
https://www.dmepdac.com/resources/articles/2006/08_14_06.pdf on September 20, 2010.  
12 Standard power wheelchairs are HCPCS code K0823, and complex rehabilitation 
power wheelchairs are HCPCS codes K0835K0843 and K0848K0864.  DMEPOS Supplier 
Quality Standards, August 2007, p. 11.  The remaining 20 percent of claims were for power 
wheelchairs with characteristics similar to those of standard power wheelchairs; these 
power wheelchairs are reimbursed under HCPCS codes K0813K0831.   
13 OIG analysis of claims from the National Claims History file submitted under HCPCS 
codes K0823 and K0835K0864 with dates of service from January 1 to June 30, 2007, 
processed as of June 30, 2007.   
14 PDAC contractor, Motorized Wheelchair Product Classification List, April 21, 2010.   
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Standard power wheelchairs.  Standard power wheelchairs are designed 
for daily use to provide basic mobility for persons weighing less than 
300 pounds.  Accessories, such as armrests and oxygen tank carriers, 
may be added to standard power wheelchairs.15   
In the first half of 2007, standard power wheelchairs accounted for 
nearly three-quarters of Medicares claims and expenditures for power 
wheelchairs.16  Medicare covers 100 models of standard power 
wheelchairs under HCPCS code K0823.17  
Medicares 2007 fee schedule amount for standard power wheelchairs 
was $4,024.18  In January 2009, the fee schedule amount for such 
wheelchairs was reduced by 9.5 percent, to $3,641.19 
Complex rehabilitation power wheelchairs.  To receive a complex 
rehabilitation power wheelchair, a beneficiary must meet criteria 
beyond those required to receive a standard power wheelchair.  The 
beneficiarys mobility limitation must either (1) require one or more 
power options or a ventilator; or (2) result from a neurological condition, 
muscle disease, or skeletal deformity.20  The beneficiary must also have 
received a specialty evaluation, and the beneficiarys weight should be 
 
15 In the first half of 2007, standard power wheelchairs were supplied with an average of 
two accessories.  Medicares average allowed amount for an accessory for a standard power 
wheelchair was $234.  OIG analysis of claims from the National Claims History file 
submitted under HCPCS code K0823 with dates of service from January 1 to June 30, 2007, 
processed as of June 30, 2007.   
16 OIG analysis of claims from the National Claims History file submitted under HCPCS 
code K0823 with dates of service from January 1 to June 30, 2007, processed as of June 30, 
2007.   
17 Medicare PDAC contractor, Motorized Wheelchair Product Classification List, loc. cit. 
18 DME, Prosthetics, Orthotics, and Supplies (DMEPOS) 2007 Fee Schedule.   Accessed 
at http://www.cms.gov/DMEPOSFeeSched/LSDMEPOSFEE/list.asp#TopOfPage on June 1, 
2011. 
19 In July 2008, the Medicare Improvements for Beneficiaries and Providers Act of 2008 
(MIPPA) delayed and reformed the Medicare DMEPOS Competitive Bidding Program.  To 
offset the cost savings lost by this delay, MIPPA reduced fee schedule amounts in 
January 2009 by 9.5 percent.  In January 2011, Medicare began to use prices from the 
Round 1 Rebid of the Competitive Bidding Program in nine geographical areas.  Under the 
program, Medicare and its beneficiaries will pay between $2,276 and $2,716 for standard 
power wheelchairs. 
20 Local Coverage Determination (LCD) for Power Mobility Devices, Indications and 
Limitations of Coverage and/or Medical Necessity.  Also, see Medicares LCD for 
Wheelchair Options/Accessories. 
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less than or equal to the weight capacity of the power wheelchair type 
that is provided.21  
In the first half of 2007, complex rehabilitation power wheelchairs 
accounted for less than 7 percent of Medicare power wheelchair claims 
and expenditures.22, 23  Medicare covers 299 models of complex 
rehabilitation power wheelchairs under 26 HCPCS codes.24   
As with standard power wheelchairs, a variety of accessories may be 
added to complex rehabilitation power wheelchairs.  Unlike standard 
power wheelchairs, complex rehabilitation power wheelchairs can also 
be upgraded with power options (e.g., a power seating system) or many 
other electronic features (e.g., a device to enable the user to control the 
chair by sipping and puffing through a straw). 25  We refer collectively to 
the power options and other electronic features that can be added to 
complex rehabilitation power wheelchairs as power options.   
Medicares 2007 fee schedule amounts for complex rehabilitation power 
wheelchairs ranged from $4,132 to $11,965.26  In January 2009, fee 
schedule amounts for complex rehabilitation power wheelchairs were 
reduced by 9.5 percent, to a range of $3,739 to $10,828.27    
Medicare Clinical Coverage Criteria for Power Wheelchairs, Power Options, 
and Accessories  
General provisions of the Social Security Act (the Act) govern Medicare 
reimbursement for all items and services, including power wheelchairs. 
 
21 LCD for Power Mobility Devices, Indications and Limitations of Coverage and/or 
Medical Necessity.   
22 Complex rehabilitation power wheelchairs include HCPCS codes K0835K0864.  
23 OIG analysis of claims from National Claims History file submitted under HCPCS 
codes K0835K0864 with dates of service from January 1 to June 30, 2007, processed as of 
June 30, 2007. 
24 Medicare PDAC contractor, Motorized Wheelchair Product Classification List, loc. cit. 
25 In the first half of 2007, complex rehabilitation power wheelchairs were supplied with 
an average of five power options and/or accessories.  Medicares average allowed amount for 
a power option or an accessory supplied with a complex rehabilitation power wheelchair 
was $995.  OIG analysis of claims from National Claims History file associated with claims 
submitted under HCPCS codes K0835K0864 with dates of service from January 1 to 
June 30, 2007, processed as of June 30, 2007.   
26 DMEPOS 2007 Fee Schedule ceiling amounts for HCPCS codes K0835 and K0864. 
27 In July 2008, MIPPA delayed and reformed the Medicare DMEPOS Competitive 
Bidding Program.  To offset the cost savings lost by this delay, MIPPA reduced fee schedule 
amounts in January 2009 by 9.5 percent.  MIPPA also exempted complex rehabilitation 
power wheelchairs from the Competitive Bidding Program. 
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  Section 1862(a)(1)(A) of the Act states that no payment may be made 
for items or services that are not reasonable and necessary for the 
diagnosis or treatment of illness or injury or to improve the 
functioning of a malformed body member.28 
  Section 1833(e) of the Act requires that suppliers furnish such 
information as may be necessary in order to determine the amounts 
due to receive Medicare payment.29 
Coverage criteria for power wheelchairs are found in Medicares 
National Coverage Determination (NCD) for Mobility-Assistive 
Equipment and LCD for Power Mobility Devices. 30  The NCD 
establishes an approach to coverage that requires a sequential analysis 
of a patients mobility status, and the LCD integrates this approach to 
establish a comprehensive standard for the provision of power 
wheelchairs.  Relevant sections of the NCD and LCD are included in 
Appendix A.    
Until 2005, CMS used a bed- or chair-confined standard to establish 
the medical necessity of a power wheelchair. 31  In 2005, CMS published 
revised criteria that more closely tied Medicare coverage for a power 
wheelchair to a beneficiarys medical condition and ability to function in 
the home.  According to the revised coverage criteria, power wheelchairs 
and other mobility-assistive equipment are medically necessary for 
beneficiaries who have mobility limitations that impair their 
participation in mobility-related activities of daily living, such as using 
the toilet, feeding, dressing, and bathing.  A power wheelchair is 
 
28 42 CFR  411.15(k)(1). 
29 42 CFR  424.5(a)(6).  This requirement applies to the entity that submits the claim 
for payment to Medicare; in the case of power wheelchairs, the supplier submits the claim.  
30 Medicare National Coverage Determinations Manual,  280.3.  Mobility-assistive 
equipment is a DME category that includes canes, crutches, walkers, manual wheelchairs, 
scooters, and power wheelchairs.  The term power mobility devices includes power-
operated vehicles (scooters) and power wheelchairs.   
The LCD for Power Mobility Devices includes detail beyond that in the NCD regarding 
nonclinical coverage criteria (i.e., documentation) and clinical coverage criteria for power 
wheelchairs.  Medicares four DME Medicare Administrative Contractors (MAC) have 
adopted the same LCD for Power Mobility Devices.  The relevant LCD policy numbers are 
L21271, L23613, L23598, and L27239.   
31 CMSs Medicare Learning Network, loc. cit.  Until 2005, a power wheelchair was 
covered when the beneficiarys condition was such that, without the use of a wheelchair, the 
beneficiary would otherwise be bed- or chair-confined; a wheelchair was medically 
necessary and the beneficiary was unable to operate a wheelchair manually; and the 
beneficiary was capable of safely operating the controls for the power wheelchair.  
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medically necessary when a beneficiarys mobility deficit cannot be 
addressed using other types of mobility-assistive equipment, such as a 
cane, manual wheelchair, or scooter.  Additional criteria for a power 
wheelchair include: 
  a beneficiary or a beneficiarys caregiver must be willing and able, 
physically and mentally, to operate a power wheelchair; and 
  a beneficiarys home must provide adequate access between rooms, 
maneuvering space, and surfaces for the operation of the power 
wheelchair that is provided. 
To qualify for specific types of power wheelchairs, a beneficiary must 
meet additional criteria.32  For example, his or her weight must be less 
than or equal to the capacity of the power wheelchair.  Additionally, 
some power wheelchairs are medically necessary only when a 
beneficiary has a certain diagnosis.   
Power options and accessories are covered only if the beneficiary has a 
power wheelchair that meets Medicare coverage criteria.33  Medicares 
LCD for Wheelchair Options/Accessories specifies additional coverage 
criteria.  See Appendix B for criteria for some power options and 
accessories. 
Prescribing and Providing Power Wheelchairs to Medicare Beneficiaries  
A Medicare beneficiary may be prescribed a power wheelchair by a 
physician after the physician conducts a face-to-face examination.  
During this examination, the physician assesses the beneficiarys 
medical condition and mobility needs and determines whether a power 
wheelchair is medically necessary as part of an overall treatment 
plan.34  CMS requires that a beneficiary who needs a complex 
rehabilitation power wheelchair receive an additional specialty 
evaluation, which must be performed by a medical professional with 
 
32 These are detailed in the LCD for Power Mobility Devices. 
33 Medicares LCD for Wheelchair Options/Accessories.   
34 42 CFR  410.38(c)(2)(i).  CMS has stated:  We believe the beneficiarys physician or 
treating practitioner is in the best position to evaluate and document the beneficiarys 
clinical condition and PMD [power mobility device] medical needs, and good medical 
practice requires that this evaluation be adequately documented.  71 Fed. Reg. 17024 
(Apr. 5, 2006).   
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experience in evaluations for rehabilitation power wheelchairs, such as 
an occupational or physical therapist.35   
From a prescribing physician, a supplier receives a prescription for a 
power wheelchair and documentation from the beneficiarys medical 
record to support the medical necessity of the power wheelchair.36  
Supporting medical documentation includes the report from the face-to-
face examination and any other parts of the beneficiarys medical record 
needed to support the medical necessity of the power wheelchair.  For 
complex rehabilitation power wheelchairs, the specialty evaluation 
report is part of the supporting medical documentation.  Based on the 
prescription and supporting medical documentation, the supplier 
recommends a type of power wheelchair for the beneficiary; the type 
must be approved by the prescribing physician.37  The supplier is also 
responsible for assessing the beneficiarys home environment before or 
during the delivery of the power wheelchair to verify that the 
beneficiary can adequately maneuver the chair in his or her home.38  
CMS Activities To Improve Compliance With Medicare Power Wheelchair 
Requirements 
CMS is responsible for paying Medicare claims and ensuring the 
integrity of those payments.  CMS employs contractors that perform 
many functions to prevent, identify, and recover inappropriate Medicare 
payments for power wheelchairs.  For example, DME MACs publish a 
variety of educational materials for suppliers and prescribing 
physicians.  They also host educational symposia, ask-the-contractor 
calls, Web-hosted seminars, and online tutorials (podcasts).  The DME 
MACs also publish Dear Physician letters for suppliers to educate 
physicians on coverage criteria for specific items, including power 
mobility devices.     
Additionally, MIPPA required all DMEPOS suppliers to meet quality 
standards for Medicare accreditation by September 30, 2009.  The 
standards that CMS developed include business standards in areas such 
as suppliers administration, consumer services, and product safety.  
Suppliers must also meet product-specific standards.  For example, 
 
35 LCD for Power Mobility Devices.  The specialty evaluation report must document the 
medical necessity for the power wheelchair and each recommended option and accessory.   
36 LCD for Power Mobility Devices, Documentation Requirements. 
37 Ibid. 
38 Ibid. 
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power wheelchair suppliers are required to provide the beneficiary with 
appropriate equipment for trial and simulation, when necessary and 
verify that seating, positioning and specialty assistive technology have 
been evaluated and documented in the beneficiarys record.39, 40   
In February 2011, CMS published a final rule implementing provisions 
of ACA that establish procedures under which screening is conducted 
for providers of medical or other services and suppliers in the Medicare 
program.41  Section 1866(j)(2)(B) of the Act requires the Secretary to 
determine the level of screening to be conducted according to the risk of 
fraud, waste, and abuse with respect to the category of provider or 
supplier.  CMS created three levels of risk:  limited, moderate, and 
high.42  New DMEPOS suppliers were placed at the high risk level, 
while currently enrolled DMEPOS suppliers were placed at the 
moderate risk level.43 
Medical Record Review by Medicare Contractors 
Medicare contractors are required to analyze providers and suppliers 
compliance with Medicare coverage and coding requirements and to 
take corrective action when instances of noncompliance are identified.44  
As part of this, contractors conduct medical reviews of supporting 
documentation for selected claims to determine whether the claims met 
Medicare coverage criteria.45  Every year, the Medicare Comprehensive 
Error Rate Testing (CERT) contractor reviews medical records to 
 
39 DMEPOS Supplier Quality Standards.  Accessed at 
http://www.cms.hhs.gov/MedicareProviderSupEnroll/Downloads/DMEPOSAccreditationSta
ndards.pdf on December 5, 2008. 
40 The requirement pertaining to equipment trials applies only to suppliers of complex 
rehabilitation power wheelchairs.   
41 76 Fed. Reg. 5864, 5865 (Feb. 2, 2011).   
42 Screening will include a licensure check, which may include checks across State lines, 
and the screening may also include (1) a fingerprint-based criminal background check; 
(2) unscheduled or unannounced site visits, including preenrollment site visits; (3) database 
checks, including checks across State lines; and other screening as the Secretary determines 
appropriate. 
43 To maintain Medicare billing privileges, a DMEPOS supplier must resubmit and 
recertify the accuracy of its enrollment information every 3 years.  42 CFR  424.57(e). 
44 CMSs Medicare Program Integrity Manual, Pub. No. 100-08, ch. 3,  3.1. 
45 Contractors select claims for medical review by first selecting areas for review (e.g., 
providers, services) that are deemed high priority.  Using claims data, the contractor 
determines the degree to which a potential error is widespread and meets established 
deviation indicators.  If no legitimate explanation exists, the contractor selects a sample of 
cases representative of the universe in which the problem is occurring.  CMSs Medicare 
Program Integrity Manual, Pub. No. 100-08, ch. 3,  3.2. 
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establish a national paid-claims error rate for the Medicare 
Fee-for-Service program.  DME MACs and other benefit integrity 
contractors use error rates produced by the CERT contractor to target 
their efforts to prevent improper payments.46 
CMS directs its contractors to collect medical records from the provider 
or supplier submitting the claim.  However, CMS does not require 
contractors to review records from the prescribing physician or any 
other providers that rendered care to the beneficiary.  If the contractors 
choose to collect records from these other providers, they must first or 
simultaneously solicit the same information from the provider or 
supplier submitting the claim.47   
In 2006, OIG found that the CERT review of DME claims relied 
primarily on supplier records.48  When additional medical records from 
physicians and other health care providers were reviewed, OIG found a 
large number of additional errors, including claims for medically 
unnecessary power wheelchairs, that were not identified by CMSs 
CERT contractor.  OIG made a series of recommendations, among them 
that the CERT contractor review all medical records (including the 
records of prescribing physicians) necessary to determine compliance 
with applicable medical necessity requirements.  CMS concurred, and in 
2007, its CERT contractor began asking physicians, in addition to 
suppliers, for supporting information.49   
Prior Office of Inspector General Work 
OIG has issued multiple reports in recent years identifying substantial 
vulnerabilities among Medicare power wheelchair claims and other 
DMEPOS claims.  In April 2004, OIG reported on the medical necessity 
of power wheelchairs provided to Medicare beneficiaries during 2001.50  
 
46 CMSs Medicare Program Integrity Manual, Pub. No. 100-08, ch. 1,  1.3.1. 
47 CMSs Medicare Program Integrity Manual, Pub. No. 100-08, ch. 3,  3.4.1.2. 
48 HHS OIG, Medical Review of Claims for the Fiscal Year 2006 Comprehensive Error 
Rate Testing Program, A-01-07-00508, August 2008.   
49 OIG also recommended that CMS establish a written policy to address the appropriate 
use of clinical inference (i.e., a clinicians interpretation of the claims appropriateness based 
on the medical record, considering the full scope of the beneficiarys circumstances).  The 
primary modification resulting from CMSs concurrence with the recommendation was to 
require the CERT medical reviewers to strictly follow the documentation requirements 
outlined in the Medicare regulation, statute and policy, including LCDs, rather than 
allowing for clinical review judgment based on billing history and other available 
information. 
50 HHS OIG, Medicare Payments for Power Wheelchairs, OEI-03-02-00600, April 2004.   
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In that report, OIG found that only 13 percent of claims met Medicares 
coverage criteria.  After CMS revised in 2005 and 2006 its policies 
related to power wheelchair coverage and coding, OIG began a series of 
reports on Medicare payments for power wheelchairs provided during 
the first half of 2007.   
Since 2009, OIG has issued two reports that assessed compliance with 
different Medicare requirements for power wheelchairs.  Both reports 
are based on the same sample (of standard power wheelchairs and 
complex rehabilitation power wheelchairs supplied to Medicare 
beneficiaries in the first half of 2007) used in this report.51  In the first 
report, OIG found that 8 percent of claims for standard and complex 
rehabilitation power wheelchairs from the first half of 2007 were 
miscoded.52  OIG reviewed supplier-submitted manufacturer invoices 
for power wheelchairs and determined whether claims were miscoded 
(i.e., whether the HCPCS code that the supplier used to bill Medicare 
matched the model information on the invoice).  In the second report, 
OIG found that 60 percent of claims for standard and complex 
rehabilitation power wheelchairs did not meet Medicare documentation 
requirements during the first half of 2007.53  OIG determined the extent 
to which suppliers submitted documents that included all required 
information and whether suppliers received the documents from 
prescribing physicians within required timeframes.   
Further, OIG issued multiple reports between 2005 and 2009 
identifying substantial vulnerabilities in the Medicare DMEPOS 
 
51 Additionally, OIG issued a report on the power wheelchair fee schedule amounts in the 
Medicare program.  HHS OIG, Power Wheelchairs in the Medicare Program:  Supplier 
Acquisition Costs and Services, OEI-04-07-00400, August 2009. 
52 HHS OIG, Miscoded Claims for Power Wheelchairs in the Medicare Program,  
OEI-04-07-00403, July 2009.  Power wheelchairs are assigned HCPCS codes based on the 
manufacturers model information.  Miscoded claims were defined as those for which the 
suppliers billed Medicare using HCPCS codes that did not match the model information on 
the invoices for power wheelchairs supplied to beneficiaries.   
53 HHS OIG, Medicare Power Wheelchair Claims Frequently Did Not Meet 
Documentation Requirements, OEI-04-07-00401, December 2009.  The December 2009 
report did not determine whether the required documents were sufficient to support the 
medical necessity of the power wheelchairs or whether the power wheelchairs were 
medically necessary because this review used a medical record review to address those 
questions.   
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benefit.54  These problems include deficiencies in enrollment safeguards, 
excessive payments, inappropriate payments, and issues with provider 
appeals.  For example, when OIG conducted unannounced site visits to 
1,581 DME suppliers in South Florida in late 2006, nearly a third either 
did not maintain physical facilities or were not open and staffed.  OIG 
has made a variety of recommendations to CMS to address these 
vulnerabilities, including strengthening the supplier enrollment 
process.  CMS has implemented many of these recommended changes; 
however, OIG continues to find significant vulnerabilities. 
Based on joint investigations by the Department of Justice (DOJ), CMS, 
and OIG, in recent years numerous DMEPOS suppliers have been 
charged with and convicted of defrauding the Medicare program, and 
many have had their Medicare billing privileges revoked based on OIG 
work.  Examples include the 20 DME company owners and marketers, 
most of them in the Los Angeles area, who were charged in 2009 with 
allegedly billing Medicare for more than $26 million in fraudulent 
claims for power wheelchairs, orthotics, and hospital beds.55  Effective 
January 1, 2007, CMS revoked the billing privileges of 491 South 
Florida DME suppliers that did not maintain appropriate physical 
facilities or had facilities that were not accessible to beneficiaries during 
reasonable or posted business hours on at least two visits.56   
METHODOLOGY 
Scope 
This evaluation focused on standard and complex rehabilitation power 
wheelchairs provided to Medicare beneficiaries during the first half of 
2007.  Our population consisted of claims for new, nonrental power 
wheelchairs from CMSs National Claims History DME Standard 
 
54 For example, HHS OIG, South Florida Suppliers Compliance With Medicare 
Standards:  Results From Unannounced Visits, OEI-03-07-00150, March 2007;  HHS OIG, 
Los Angeles County Suppliers Compliance with Medicare Standards:  Results From 
Unannounced Visits, OEI-09-07-00550, February 2008; HHS OIG, South Florida Medical 
Equipment Suppliers:  Results of Appeals, OEI-03-07-00540, October 2008; HHS OIG, 
Power Wheelchairs in the Medicare Program:  Supplier Acquisition Costs and Services, 
OEI-04-07-00400, August 2009. 
55 DOJ, Office of Public Affairs, Los Angeles Medicare Fraud Strike Force Charges 20 in 
Health Care Fraud Cases Involving Durable Medical Equipment.  Accessed at 
http://www.justice.gov/opa/pr/2009/October/09-crm-1131.html on February 23, 2011. 
56 HHS OIG, South Florida Medical Equipment Suppliers:  Results of Appeals,  
OEI-03-07-00540, October 2008. 
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Analytical File with dates of service in the first half of 2007.57  We based 
this evaluation on data from a medical record review of a random 
sample of power wheelchair claims.   
Based on suppliers records, we determined whether power wheelchairs 
met clinical coverage criteria.  We also reviewed the medical necessity of 
power options and accessories supplied with complex rehabilitation 
power wheelchairs.  We did not review accessories supplied with 
standard power wheelchairs because beneficiaries who received such 
wheelchairs needed fewer, less expensive accessories.  We did not 
determine whether sampled power wheelchair claims were coded 
correctly or met nonclinical documentation requirements; in separate 
reports, OIG has noted the rates of miscoding and documentation error 
in power wheelchair claims.58  We also reviewed prescribing physicians 
records.  However, we did not determine whether claims met clinical 
coverage criteria based on physicians records.   
Sample Selection 
We removed from our population claims from suppliers or prescribing 
physicians under OIG investigation and claims from suppliers that were 
inactive or whose billing privileges had been revoked since the time they 
submitted the claims.59, 60   We grouped the resulting population into 
three strata:  
 
57 We analyzed claims that CMS processed as of June 30, 2007.  That claims file is 
estimated to be 79 percent complete; that is, it included 79 percent of all claims for power 
wheelchairs provided during the first half of 2007.   
58 Miscoded Claims for Power Wheelchairs in the Medicare Program, loc. cit., and 
Medicare Power Wheelchair Claims Frequently Did Not Meet Documentation Requirement, 
loc. cit.   
59 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 in the information provided on the enrollment application, such as a change in 
practice location or ownership.  
60 After we removed these claims3,430 claims for standard power wheelchairs and 
301 claims for complex rehabilitation power wheelchairsour population consisted of 
43,133 claims for standard power wheelchairs, or 93 percent of such claims; and 
3,001 claims for complex rehabilitation power wheelchairs, or 91 percent of such claims. 
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1.  standard power wheelchair claims submitted by low-volume 
suppliers (i.e., those that submitted fewer than 10 standard power 
wheelchair claims in the first half of 2007), 61  
2.  standard power wheelchair claims submitted by high-volume 
suppliers (i.e., 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 claims by selecting simple random samples of 
125 claims from each stratum.62  Appendix C provides the number of 
claims, amount of Medicare expenditures, and number of suppliers for 
the population and sample, by stratum.   
We also identified power options and accessories supplied with complex 
rehabilitation power wheelchairs in our sample.  Claims for power 
options and accessories (1) had HCPCS codes listed in Medicares LCD 
for Wheelchair Options/Accessories and (2) shared the same unique 
control number assigned by the DME MAC as a sampled claim for a 
complex rehabilitation power wheelchair. 
Data Collection   
We requested beneficiary records from the supplier and prescribing 
physician to support each sampled claim.   
Supplier records.  We obtained the supplier addresses from the 
National Supplier Clearinghouse data file.  To increase our response 
rate, we sent an initial request and, as needed, sent at least two 
followup letters and contacted the supplier by phone.  We received or 
classified as errors 364 of the 375 power wheelchair claims, a 
97-percent response rate.  We received supplier records for 
363 claims.  We classified the single remaining claim as an error 
because the supplier received but did not respond to our third request 
letter, which was sent via certified mail.  In our analysis, we 
considered this claim to be undocumented.  We did not include the 
 
61 We divided the standard power wheelchair population by supplier volume based on the 
distribution of suppliers and claims.  For example, 25 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.  High-volume suppliers had an average of 50 standard power wheelchair claims, 
while low-volume suppliers had an average of 3 such claims.  
62 All evaluations in the current series of OIG power wheelchair reports, described 
earlier in the report, use this sample methodology.  
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I N T R O D U C T I O N  
remaining 11 claims in our analysis because we could not obtain 
current addresses for the suppliers of 10 claims and the suppliers 
record for 1 claim was in another language.63  
Prescribing physician records.  We obtained the names and addresses of 
physicians who prescribed the power wheelchairs in our sample from 
suppliers.  When suppliers did not provide this information, we obtained 
it from either the Unique Physician Identification Number Directory or 
the National Provider Identifier Directory.  We requested from the 
prescribing physician all documentation from the beneficiarys medical 
record, including office visit notes, referrals, and hospital admission 
histories and discharge summaries, during the 12 months prior to the 
date the beneficiary received the power wheelchair.   
We used a medical review contractor to collect medical records from 
prescribing physicians.  The contractor sent a request and, as needed, at 
least two followup letters and contacted the physician by phone to 
increase the response rate.  We received or classified as errors 360 of the 
375 power wheelchair claims, a 96-percent response rate.  We received 
prescribing physician records for 322 claims.  We classified the 
remaining 38 claims as errors, either because the physician received but 
did not respond to our third request letter (sent via certified mail) or 
because the documentation that the physician produced did not contain 
any information relevant to our sampled claim.  In our analysis, we 
considered these claims to be undocumented.  We did not include the 
remaining 15 claims in our analysis because we could not obtain current 
addresses for the physicians.  
Medical Record Review 
We used a contractor to conduct a medical record review of the claims in 
our sample and the power options and accessories supplied with the 
complex rehabilitation power wheelchair claims in our sample.  For 
each claim, the suppliers record and the prescribing physicians record 
were reviewed by a licensed clinician with experience in establishing 
medical necessity for power wheelchairs.  The reviewers completed a 
standardized review instrument twice for each claim in the sample:  
once based on a review of the suppliers record and once based on a 
review of the physicians record.   
 
63 We referred to CMS the suppliers that did not respond to our request or for which we 
were unable to locate current addresses.  In addition, OIG is considering these suppliers for 
investigation. 
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II NN TT RR OO DD UU CC TT II OO NN   
The reviewers determined whether claims met Medicare coverage 
criteria from the NCD for Mobility-Assistive Equipment and LCD for 
Power Mobility Devices.  They determined whether the power 
wheelchairs were medically necessary and, if not, which other type of 
mobility-assistive equipment (e.g., cane, manual wheelchair, or scooter) 
or other power wheelchair corresponding to a different HCPCS code 
would have been medically necessary, if any.  The reviewers indicated 
whether the suppliers record was insufficient to determine whether the 
power wheelchair was medically necessary.  They also determined 
whether power options and accessories provided with the complex 
rehabilitation power wheelchairs were medically necessary and had 
claims that were sufficiently documented.   
Analysis 
We aggregated data received from the medical review contractor and 
determined the percentage of sampled claims that did not meet 
Medicare coverage criteria based on the suppliers record.64  We 
identified the percentages of claims for power wheelchairs that were 
medically unnecessary, claims that were insufficiently documented to 
determine the medical necessity of the power wheelchair, and claims 
that were undocumented.  We calculated these error rates for the entire 
sample and for the following subgroups:  standard power wheelchair 
claims, complex rehabilitation power wheelchair claims, standard power 
wheelchair claims submitted by low-volume suppliers, and standard 
power wheelchair claims submitted by high-volume suppliers.  See 
Appendix D (Table D-1) for the point estimates and confidence intervals 
for the projections of these error rates.  We also determined whether 
these error rates differed significantly between claims for standard 
power wheelchairs and those for complex rehabilitation power 
wheelchairs.  See Appendix D (Table D-2) for the point estimates and 
confidence intervals associated with these statistical comparisons.      
We calculated the inappropriate payments for erroneous claims using 
Medicare-allowed amounts from the National Claims History data.  See 
Appendix D (Table D-3) for the point estimates and confidence intervals 
for inappropriate payment projections.  We calculated partial 
inappropriate payments for cases in which beneficiaries did not meet 
the coverage criteria for the provided power wheelchair but would have 
 
64 As the provider submitting the claim, the supplier must have records to support that 
the claim met coverage criteria.  Therefore, error rates are based on suppliers records. 
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I N T R O D U C T I O N  
qualified for a manual wheelchair, cane, or walker or for a different 
power wheelchair.  We derived the adjusted allowances from the 
2007 DME fee schedule ceiling amounts. 
When the beneficiary would have qualified for a manual wheelchair, a 
cane, or a walker, we used the HCPCS codes E1161 for manual 
wheelchairs and E0147 for canes or walkers because these codes had 
the highest fee schedule amounts for those types of mobility-assistive 
equipment and thus yielded the most conservative figures for 
overpayments.  When the beneficiary needed a different power 
wheelchair, we used the fee schedule amount for the appropriate power 
wheelchair (using the HCPCS code indicated by the medical record 
reviewer), calculating the loss to the Medicare program as the difference 
between the cost of the two power wheelchairs.  (If the beneficiary 
needed a more expensive power wheelchair, we subtracted that 
difference from the amount of total inappropriate payments.)  If the 
beneficiary needed a different type of power wheelchair but the reviewer 
could not determine which HCPCS code would have been appropriate, 
we did not consider any portion of the allowed amount to be 
inappropriate.   
We also identified the percentage of power options and accessories that 
were medically unnecessary or insufficiently documented to determine 
medical necessity.65  Finally, we identified the percentage of claims for 
complex rehabilitation power wheelchairs for which at least one power 
option or accessory was medically unnecessary or insufficiently 
documented to determine medical necessity.66  See Appendix D 
(Table D-4) for the point estimates and confidence intervals for the 
projections of these error rates.  
We determined whether the records from prescribing physicians 
supported claims that suppliers submitted.  For claims for which the 
suppliers records indicated no errors, we determined whether the 
prescribing physicians records yielded the same determinationsthat 
is, we identified claims that the prescribing physicians records 
indicated were for medically unnecessary power wheelchairs, had 
insufficient documentation, or were undocumented.  We removed from 
 
65 This analysis is based on 556 claims for power options and accessories provided with 
sample complex rehabilitation power wheelchair claims. 
66 This analysis is based on the 108 claims for complex rehabilitation power wheelchairs 
supplied with at least one power option or accessory.  
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our analysis claims for which the only difference between the suppliers 
records and the physicians records was that the former contained a 
home assessment report and the latter did not.67  See Appendix D 
(Table D-5) for the point estimates and confidence intervals for the 
projections of these calculations.      
Finally, we calculated the combined error rate across the three OIG 
reports that had each calculated error rates based on the same sample 
of power wheelchairs.68  We calculated the combined error rate based on 
two sets of claims from the shared sample of 375 claims:  (1) the 
339 claims that were reviewed in all three reports and (2) the 
365 claims that were reviewed in at least one of the three reports.  See 
Appendix D (Table D-6) for the point estimates and confidence intervals 
for the projections of these error rates. 
We projected the error rates, total inappropriate payments, and rates of 
inconsistency between supplier and physician records to the populations 
defined by the strata from which we selected sample claims.  We used 
SAS and SUDAAN survey data analysis software to project these 
results.  Appendix D includes the point estimates and confidence 
intervals for all reported projections. 
Limitations 
Our results cannot be extrapolated beyond the timeframe of our 
evaluation.  We recognize that since the first half of 2007, CMS has 
continued to educate suppliers and prescribing physicians about its 
power wheelchair clinical coverage criteria and has implemented 
additional program integrity safeguards.  Additionally, all suppliers 
were required to meet quality standards as of September 30, 2009.  
Although CMS has taken steps since 2007 to decrease errors among 
suppliers of power wheelchairs and other kinds of DME, Medicare has 
 
67 This analysis is based on 121 claims.  There were 140 claims without errors in the 
supplier record.  From these, we removed 19 claims for which the only difference between 
the suppliers records and the physicians records was that the former contained home 
assessment reports and the latter did not.  Discrepancies arising because of this difference 
between records are acceptable; the supplier must have the home assessment report on file, 
but the prescribing physician is not explicitly required to have this report.  This analysis 
includes only claims for which we either received the supplier record and the physician 
record or did not receive a response from the supplier and considered the claim to be 
undocumented.   
68 The three reports are this report and two others:  Miscoded Claims for Power 
Wheelchairs in the Medicare Program, loc. cit.; and Medicare Power Wheelchair Claims 
Frequently Did Not Meet Documentation Requirement, loc. cit.   
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paid significantly more for power wheelchairs in recent years than it did 
in 2007.69  
Standards  
This study was conducted in accordance with the Quality Standards for 
Inspection and Evaluation issued by the Council of the Inspectors 
General on Integrity and Efficiency. 
 
 
69 Medicare and its beneficiaries paid $658 million for power wheelchairs in 2007, 
$779 million in  2008, and $723  million in 2009.   
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 F I N D I N G S  
Based on records submitted by 
Sixty-one percent of power wheelchairs 
suppliers that provided power 
provided to Medicare beneficiaries in the first 
wheelchairs, 9 percent of claims 
half of 2007 were medically unnecessary or had  were for power wheelchairs that 
claims that lacked sufficient documentation to  were medically unnecessary and 
determine medical necessity  another 52 percent had insufficient 
documentation to determine 
whether the power wheelchairs 
were medically necessary.70  Because of these errors, these claims 
should not have been paid.  However, Medicare and its beneficiaries 
paid $95 million for power wheelchairs provided in the first half of 2007 
that were medically unnecessary, had claims with insufficient 
documentation, or had claims that were undocumented, out of  
$189 million allowed by Medicare.  Table 1 presents the percentage of 
claims that had each type of error and the associated Medicare 
payments.   
Table 1:  Error Rates for Medicare Power Wheelchairs, First Half of 2007 
Type of Error  Claim Error  Inappropriate 
Rate  Payments 
Power Wheelchair Was Medically Unnecessary *  9%  $2 million 
Beneficiary needed a less expensive type of  2%   
equipment (i.e., not a power wheelchair) 
Beneficiary needed a different type of power  7%   
wheelchair 
Claim Had Insufficient Documentation  52%      $93 million 
Claim Was Undocumented *  <1%  <$1 million 
      Total Errors  61%  $95 million 
* We are unable to reliably project the weighted point estimates for inappropriate payments associated with 
these error rates because of the small number of sample claims in these categories.  We did not include the 
95-percent confidence intervals for these estimates in Appendix D.   
 
Source:  OIG medical record review of Medicare power wheelchair claims. 
Two previous OIG reports based on the same sample of claims for power 
wheelchairs found problems with coding and documentation 
 
70 Additionally, less than 1 percent of claims for power wheelchairs were 
undocumentedthat is, the supplier did not submit any medical records to document the 
claims.  Claims that lack documentation to show that the care was reasonable and 
necessary do not meet Medicare coverage criteria. 
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F I N D I N G S  
requirements.71  Across all three reports, 80 percent of claims for power 
wheelchairs supplied to Medicare beneficiaries in the first half of 
2007 did not meet Medicare requirements.72  In the current report, we 
found that 61 percent of claims were for wheelchairs that were 
medically unnecessary or had insufficient documentation to determine 
medical necessity.  In the two previous reports, OIG found that  
8 percent of claims were miscoded and 60 percent did not meet 
documentation requirements; many claims had more than one of these 
error types. 
Nine percent of power wheelchairs were medically unnecessary  
Claims for 9 percent of power wheelchairs provided to Medicare 
beneficiaries in the first half of 2007 were for power wheelchairs that 
were medically unnecessary.  Beneficiaries who received power 
wheelchairs that were medically unnecessary needed a less expensive 
type of medical equipment or a different type of power wheelchair.  For 
2 percent of power wheelchair claims, a less expensive type of 
equipment (e.g., a manual wheelchair, cane, or walker) would have been 
more appropriate.  For another 7 percent of claims, the beneficiaries 
should have received a different type of power wheelchair than was 
provided.  The beneficiaries should have received a less expensive power 
wheelchair for 1 percent of all claims.  For another 3 percent of claims, 
the beneficiaries needed a more expensive power wheelchair.73   
Regardless of whether a more expensive or less expensive power 
wheelchair was needed, Medicare paid for the wrong equipment to meet 
these beneficiaries needs.  These claims did not meet Medicare clinical 
coverage criteria as stated in the NCD and LCD.  Examples of these 
types of inappropriate power wheelchairs from our sample are: 
 Claim A:  The beneficiary received a complex rehabilitation power 
wheelchair for which Medicare allowed $5,081.  This type of power 
wheelchair is necessary for beneficiaries with a neurological, 
 
71 Miscoded Claims for Power Wheelchairs in the Medicare Program, loc. cit., and 
Medicare Power Wheelchair Claims Frequently Did Not Meet Documentation Requirement, 
loc. cit.   
72 Based on sample claims that were reviewed in all three reports.  We also calculated 
the combined error rate using claims that were reviewed in at least one of the three reports.  
These claims yielded a combined error rate of 79 percent.     
73 For the remaining 3 percent of claims for which the beneficiary should have received a 
different power wheelchair, the reviewer could not determine the specific power wheelchair 
that the beneficiary needed.  Therefore, we did not consider any portion of the  
Medicare-allowed amount to be inappropriate.   
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F I N D I N G S  
muscular, or skeletal deformity.  However, the beneficiary had a 
diagnosis of chronic obstructive pulmonary disease and cardiac 
disease.  Therefore, the beneficiary should have received a standard 
power wheelchair for which Medicare would have allowed up to 
$4,024.   In this situation, Medicare overpaid by $1,057. 
 Claim B:  The beneficiary received a complex rehabilitation power 
wheelchair with a weight capacity of 301 450 pounds, for which 

Medicare allowed $6,130.  However, the beneficiary weighed 
85 pounds.  Therefore, he should have received a complex 
rehabilitation power wheelchair with a weight capacity of less than 
300 pounds for which Medicare would have allowed up to $5,672.  In 
this situation, Medicare overpaid by $458.   
 Claim C:  The beneficiary received a complex rehabilitation power 
wheelchair with an automotive-style seat for which Medicare 
allowed $4,208.  However, she had a neurological diagnosis that 
results in poor sitting balance and a high risk of skin breakdown.  
Therefore, she needed a power wheelchair with a rehabilitation seat 
providing better postural support and skin protection.  For such a 
wheelchair, Medicare would have allowed up to $5,672.  In this 
situation, Medicare underpaid by $1,464.   
Fifty-two percent of claims for power wheelchairs had insufficient 
documentation to determine medical necessity  
Claims for 52 percent of power wheelchairs provided during the first 
half of 2007 were insufficiently documented.  That is, suppliers records 
were insufficient to enable reviewers to determine whether these power 
wheelchairs were medically necessary.  Inappropriate payments for 
these claims totaled $93 million.   
Suppliers are required to maintain documentation that supports the 
appropriateness of claims they submit for Medicare reimbursement.  
These claims did not contain sufficient documentation to show that they 
met Medicare clinical coverage criteria as stated in the NCD and LCD.  
Examples of sampled claims that did not have sufficient documentation 
are: 
 Claim D:  The record did not provide sufficient information about the 
beneficiarys ability to participate in mobility-related activities of daily 
living, ability to use the power wheelchair in her home, or ability to 
use the power wheelchair safely.  Additionally, the documentation did 
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F I N D I N G S  
not rule out other, less expensive types of mobility-assistive 
equipment. 
 Claim E:  The record did not explain why the beneficiary needed a 
power wheelchair.  The report of the face-to-face examination by the 
prescribing physician documented a diagnosis of osteoporotic hip 
fracture, which is usually reversible following the surgery that the 
beneficiary received.  However, the report did not explain how the 
beneficiarys condition had changed to require a power wheelchair.  
That is, it did not contain sufficient documentation to show that the 
claims met Medicare clinical coverage criteria. 
 
Claims for standard and complex 
Medical necessity and documentation errors 
rehabilitation power wheelchairs 
varied by power wheelchair type 
had similar overall error rates.  
However, standard power 
wheelchairs were less likely to be 
medically unnecessary than complex rehabilitation power wheelchairs.  
Conversely, claims for standard power wheelchairs were more likely to 
have insufficient documentation than were claims for complex 
rehabilitation power wheelchairs.74  Because standard power 
wheelchairs accounted for most of Medicares power wheelchair 
expenditures, errors among claims for standard power wheelchairs 
resulted in higher inappropriate payments than did errors among 
claims for complex rehabilitation power wheelchairs.75  
 
74 The differences in error rates between the two power wheelchair types are statistically 
significant at the 95-percent confidence level.   
75 Standard power wheelchairs accounted for 73 percent of Medicares power wheelchair 
expenditures in the first half of 2007 and 92 percent of the population we reviewed, which 
did not include power wheelchairs reimbursed under HCPCS codes K0813K0817,  
K0820K0822, and K0824K0831.  
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F I N D I N G S  
Figure 1 illustrates the differences between the percentage of error 
rates for claims for standard and complex rehabilitation power 
wheelchairs.   
   
Figure 1:   
Percentage of Error Rates  
for Claims for Standard and   
Complex Rehabilitation Power 
Wheelchairs, First Half of 2007     
 
 
 
 
 
 
 
 
Total errors:  61%  Total errors:  56% 
 
Notes:  In addition to claims for power wheelchairs that were medically unnecessary and claims that had insufficient 
documentation, less than 1 percent of claims for standard power wheelchairs were undocumented.  No claims for complex 
rehabilitation power wheelchairs were undocumented.  Error rates for claims for complex rehabilitation power wheelchairs 
do not sum to 57 percent because of rounding. 
Source:  OIG medical record review of Medicare claims for power wheelchairs, 2010. 
Standard power wheelchairs.  In the first half of 2007, 61 percent of 
Medicare standard power wheelchairs were medically unnecessary or 
had claims that were insufficiently documented.  Eight percent were 
medically unnecessary, and another 53 percent had claims with 
insufficient documentation to determine medical necessity.  In total, 
these errors for claims for standard power wheelchairs resulted in 
$90 million in inappropriate payments.   
Beneficiaries who received medically unnecessary standard power 
wheelchairs needed either a different and less expensive type of 
equipment or a more expensive power wheelchair, such as a complex 
rehabilitation power wheelchair.  For 2 percent of claims for standard 
power wheelchairs, a less expensive manual wheelchair, cane, or walker 
should have been provided.  For another 3 percent of claims, 
beneficiaries should have received power wheelchairs that were more 
expensive than the ones provided.76 
 
76 For another 3 percent of claims, beneficiaries should have received a different power 
wheelchair, but the reviewer could not determine which specific power wheelchair 
beneficiaries needed.   
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F I N D I N G S  
The difference in error rates between standard power wheelchairs 
supplied by low- and high-volume suppliers was not statistically 
significant.  Sixty-six percent of standard power wheelchairs provided 
by low-volume suppliers were medically unnecessary or had claims that 
were insufficiently documented, and 60 percent of those provided by 
high-volume suppliers were medically unnecessary or had claims that 
were insufficiently documented. 
Complex rehabilitation power wheelchairs.  In the first half of 2007, 
56 percent of Medicare complex rehabilitation power wheelchairs were 
medically unnecessary or had claims that were insufficiently 
documented.  Twenty-four percent of complex rehabilitation power 
wheelchairs were medically unnecessary, and another 32 percent had 
claims with insufficient documentation to determine medical necessity.  
In total, these errors for claims for complex rehabilitation power 
wheelchairs resulted in $5 million in inappropriate payments.   
Beneficiaries who received medically unnecessary complex 
rehabilitation power wheelchairs needed a different and less expensive 
type of equipment, a less expensive power wheelchair, or a more 
expensive power wheelchair.  For 1 percent of complex rehabilitation 
power wheelchair claims, a less expensive manual wheelchair should 
have been provided.  For 13 percent of claims, beneficiaries should have 
received a less expensive power wheelchair than was provided, and for 
another 6 percent of claims, beneficiaries needed a more expensive 
power wheelchair.77 
Complex rehabilitation power wheelchair options and accessories.   
Nineteen percent of power options and accessories supplied with 
complex rehabilitation power wheelchairs were medically unnecessary 
or insufficiently documented.  Four percent of the power options and 
accessories were medically unnecessary, and for another 16 percent of 
claims, beneficiaries medical records had insufficient documentation to 
determine whether the power options or accessories were medically 
necessary.78  Fourteen percent of complex rehabilitation power 
wheelchairs were supplied with at least one medically unnecessary 
 
77 For another 5 percent of claims, beneficiaries should have received a different power 
wheelchair, but the reviewer could not determine which specific power wheelchair 
beneficiaries needed.  The types of claims for medically unnecessary complex rehabilitation 
power wheelchairs do not sum to 24 percent because of rounding. 
78 The medical necessity and insufficient documentation error rates do not sum to 
19 percent because of rounding. 
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F I N D I N G S  
power option or accessory.79  Medically unnecessary power options and 
accessories resulted in $2 million in inappropriate payments in the first 
half of 2007, separate from the inappropriate payments for power 
wheelchairs.   
 
Thirty-nine percent of power 
Prescribing physicians records do not 
wheelchair claims had no errors 
support the medical necessity of most  
based on suppliers records.  
power wheelchairs 
However, 78 percent of such 
  claims were not supported by 
medical records kept by physicians who prescribed the power 
wheelchairs.  Physicians records contradicted suppliers records for        
7 percent of claims with no errors based on suppliers records.  These 
power wheelchairs were medically unnecessary based on physicians 
records.  For another 71 percent of claims with no errors based on 
suppliers records, physicians records were insufficiently documented to 
determine medical necessity or the claims were undocumented. Table 2 
presents the types of errors in physicians records for claims with no 
errors based on suppliers records. 
 
79 This analysis is based only on the 108 complex rehabilitation power wheelchairs 
supplied with at least 1 power option or accessory out of the 124 in the sample. 
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F I N D I N G S  
 
 
Table 2:  Claims With Errors Based on Prescribing Physicians 
 Records and No Errors Based on Suppliers Records, First Half of 
2007 
 
Claims Error 
 
Type of Error in Physicians Record  Rate 
 Power Wheelchair Was Medically Unnecessary   7% 
Claim Had Insufficient Documentation To Determine Medical 
 Necessity  62% 
Claim Was Undocumented  9% 
 
Total Claims  78% 
 
Source:  OIG medical record review of Medicare power wheelchair claims, 2010. 
 
 
Physicians records sometimes contradicted suppliers records  
Seven percent of power wheelchair claims that were medically 
necessary based on suppliers records were medically unnecessary based 
on prescribing physicians records.  In these cases, prescribing 
physicians records indicated that beneficiaries needed different power 
wheelchairs or did not need power wheelchairs at all.  Examples of each 
of these types of claims from our sample are:  
 Claim F:  The beneficiarys weight is recorded as 230 pounds in the 
suppliers record and as more than 350 pounds in the physicians 
record.  The physicians record also documents lower extremity edema 
and wounds.  The suppliers record does not note these impairments.  
The beneficiary received a standard power wheelchair, but based on 
the physicians record, the patient needed a complex rehabilitation 
power wheelchair.  A complex rehabilitation power wheelchair would 
have had a greater weight capacity and would have allowed for the 
addition of power options, such as elevating legrests and a power tilt 
seating system, to manage the lower extremity edema and allow 
wound healing and pressure relief. 
 Claim G:  In the suppliers record, a letter from the physician states 
that the beneficiary was recovering from a total replacement of the left 
knee.  The letter also states that the beneficiary has severe 
osteoarthritis, a history of brain surgery, and poor balance.  Finally, 
the letter states that the beneficiary is obese, unable to walk safely 
with a cane or walker, and unable to propel a manual wheelchair 
because of severe joint pain.  There is no documentation of a power 
wheelchair in the physicians record.  An entry from the physicians 
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F I N D I N G S  
record from 1 week after the date of the letter in the suppliers record 
states that the beneficiary had recovered from the knee replacement 
enough to bear her full weight and discontinue using a cane.  The 
beneficiary received a standard power wheelchair, but based on the 
physicians record, she needed a cane or walker.  
Physicians records often insufficiently documented the beneficiaries need 
for power wheelchairs 
Sixty-two percent of power wheelchair claims that were medically 
necessary based on the suppliers records were insufficiently 
documented in the physicians records.  That is, the medical records 
from the prescribing physicians were insufficient to support the medical 
necessity of these power wheelchairs.  For another 9 percent of claims 
that were medically necessary based on the suppliers records, 
physicians did not provide supporting medical records (i.e., the claims 
were undocumented).   
A physician is required to assess a beneficiarys mobility needs before 
prescribing a power wheelchair.  The report from the physicians  
face-to-face examination, along with other documentation in the 
physicians record, must support the medical necessity for the power 
wheelchair.  Examples of claims that were insufficiently documented in 
the physicians records are:  
 Claim H:  There is no documentation in the physicians record from 
the entire year in which the beneficiary received a power wheelchair.  
However, physician documentation in the suppliers record documents 
a mobility limitation and a risk of falls.  It also documents 
significantly decreased strength in bilateral upper and lower 
extremities.   
  Claim I:  Portions of the physicians record were inconsistent 
regarding the beneficiarys history of seizures.  Therefore, it is unclear 
from the physicians record whether the beneficiary had the mental 
and physical capabilities to safely operate the power wheelchair that 
was provided, a Medicare coverage requirement.  In the suppliers 
record, a note from a physical therapist documented that the 
beneficiary had not had a seizure in a long time. 
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  R E C O M M E N D A T I O N S  
A power wheelchair can greatly improve the quality of life for an 
individual with limited mobility.  However, our review found that power 
wheelchairs  paid for by Medicare are not always medically necessary, 
and claims for power wheelchairs frequently have insufficient 
documentation to support medical necessity.  In the first half of 2007, 
Medicare paid $95 million for power wheelchair claims with these 
errors. Although CMS has taken steps since 2007 to decrease errors 
among suppliers of power wheelchairs and other kinds of DME, 
Medicare has paid significantly more in recent years for power 
wheelchairs than it did in 2007.  Medicare and its beneficiaries paid 
$658 million in 2007, compared to $779 million in 2008 and $723 million 
in 2009. These increases may indicate that CMS continues to pay for 
power wheelchairs that are not medically necessary and/or have claims 
that do not meet documentation requirements.  
Additionally, we found that power wheelchairs that were medically 
necessary according to suppliers records were  often not medically 
necessary according to the records of physicians who prescribed the 
power wheelchairs, a further indication of potential fraud, waste, and 
abuse. In most cases, physicians records had insufficient 
documentation to support the  medical necessity of power wheelchairs 
and, less often, physicians records contradicted suppliers records.   
Two previous OIG reports based on the same sample of power 
wheelchairs found problems with suppliers compliance with Medicare 
requirements, and this report also shows such problems.  Across all 
three reports, 80 percent of claims for power wheelchairs supplied to 
beneficiaries in the first half of 2007 did not meet Medicare 
requirements.  In addition to finding in this report that 61 percent of 
claims were for power wheelchairs  that were medically unnecessary or 
had insufficient documentation to determine medical necessity, OIG 
found in previous reports that 8 percent of claims were miscoded and  
60 percent did not meet  documentation requirements.  Many claims had 
more than one of these error types.  
Further, in recent years OIG has issued multiple reports identifying 
substantial vulnerabilities in the Medicare DMEPOS benefit, including 
deficiencies  in enrollment safeguards, excessive payments,  
inappropriate payments, and issues with provider appeals.  OIG has 
made a variety of recommendations to CMS to address these  
vulnerabilities. Finally, numerous DMEPOS suppliers have been 
convicted of Medicare fraud.   
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R E C O M M E N D A T I O N S  
Based on the findings of this report and prior work, we recommend that 
CMS: 
Enhance reenrollment screening standards for current DMEPOS suppliers  
Federal regulations categorize provider types into three levels of risk of 
fraud, waste, and abuse:  limited, moderate, and high.  New DMEPOS 
suppliers are placed at a risk level of high, whereas currently enrolled 
DMEPOS suppliers are placed at a risk level of moderate.  Based on 
the overall error rate of 80 percent among power wheelchair claims, we 
believe that currently enrolled DMEPOS suppliers should be subject to 
the same enrollment screening standards as newly enrolling DMEPOS 
suppliers and should also be placed at the risk level of high. 
Review records from sources in addition to the supplier, such as the 
prescribing physician, to determine whether power wheelchairs are 
medically necessary 
In some cases in which the physicians records did not support the 
suppliers claims, the physicians records may not include the same level 
of detail in the suppliers records.  Alternatively, the differences may 
exist because the suppliers records contained inaccurate information 
that was included to justify the medical necessity of a power wheelchair.  
Medicare contractors are not required to review the prescribing 
physicians records, although in 2007 the CERT contractor began asking 
physicians for supporting information in response to OIGs 
recommendation.  We continue to recommend that CMS direct its 
contractors to review records from prescribing physicians as well as 
those of suppliers.   
Continue to educate power wheelchair suppliers and prescribing physicians 
to ensure compliance with clinical coverage criteria   
In 2009, CMS began requiring that DME suppliers meet quality 
standards to be accredited.  Additionally, since the first half of 2007, 
CMS contractors have developed a variety of educational materials for 
power wheelchair suppliers and prescribing physicians.  Our review 
highlights the importance of these efforts and the need for CMS to 
continue to educate, and promote collaboration between, suppliers and 
physicians.  We suggest that CMS focus its educational efforts for 
suppliers and prescribing physicians on the following topics: 
  Requirements for determining and documenting the medical necessity 
of a power wheelchair.  We found that 9 percent of power wheelchairs 
were medically unnecessary and an additional 52 percent had claims 
with insufficient documentation for reviewers to determine medical 
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R E C O M M E N D A T I O N S  
necessity.  Suppliers records must show that the power wheelchairs 
they provided were medically necessary and met beneficiaries 
mobility needs.  We suggest that CMS focus on suppliers of standard 
power wheelchairs because we found that claims for such 
wheelchairs were more likely to have insufficient documentation 
than those for complex rehabilitation power wheelchairs.  
  Collaboration between supplier and physician necessary to determine 
the most appropriate power wheelchair for a beneficiary.  Collaboration 
ensures that beneficiaries receive medically necessary power 
wheelchairs that are appropriate for their mobility needs.  
Additionally, we found that the 78 percent of claims for power 
wheelchairs that were medically necessary according to suppliers 
records were not supported by the records of the physicians who 
prescribed them.  Collaboration between the physician and the 
supplier should also result in a consistent clinical assessment of the 
beneficiary and consistent supporting records. 
  Requirements for determining the most appropriate power wheelchair 
for a beneficiary.  We found that 7 percent of beneficiaries who 
received power wheelchairs needed a different type than was 
provided.  Medicare covers hundreds of power wheelchair models 
that are reimbursed under 42 different HCPCS codes.  These power 
wheelchairs vary widely in their ability to fulfill a beneficiarys 
mobility needs.  The wrong power wheelchair not only may fail to 
address a beneficiarys mobility deficits but, in some cases, may 
harm the beneficiary.  We suggest that CMS focus on suppliers of 
complex rehabilitation power wheelchairs because we found that 
such wheelchairs were more likely to be medically unnecessary than 
standard power wheelchairs and that the beneficiaries often needed 
a different type of power wheelchair. 
Review suppliers of sampled claims we found to be in error 
In a separate transmittal, we forwarded to CMS informationincluding 
the suppliers identifying informationabout the 61 percent of claims 
that were for medically unnecessary power wheelchairs, were 
insufficiently documented to determine medical necessity, or were 
undocumented.  We also provided CMS with information on the claims 
for which physicians records contradicted suppliers records, so that 
CMS may follow up appropriately.  Finally, we will inform CMS of 
physicians for whom we could not obtain current addresses.  (We have 
OEI-04-09-00260    MOST MEDICARE POWER WHEELCHAIRS DID NOT MEET MEDICAL NECESSITY GUIDELINES  30   
   
R E C O M M E N D A T I O N S  
informed CMS of suppliers for whom we could not obtain current 
addresses.) 
AGENCY COMMENTS AND OFFICE OF INSPECTOR GENERAL 
RESPONSE 
CMS concurred with the second, third, and fourth recommendations.  
CMS did not concur with the first recommendation.  In response to the 
first recommendation, CMS stated that it has in place other tools that 
allow for increased scrutiny of some current DMEPOS suppliers.  CMS 
also noted that several triggering events can elevate individual 
suppliers from the moderate to the high risk level.  Based on this 
reports findings, which reinforce the findings of multiple OIG reports in 
recent years identifying substantial vulnerabilities in the Medicare 
DMEPOS benefit, we maintain that all current DMEPOS suppliers 
should be subject to the screening standards of the high risk level 
upon reenrollment.   
In response to the second recommendation, CMS stated that it will 
continue to emphasize the need for proper documentation from the 
prescribing physician.  We support this initiative and believe that CMS 
contractors should consider collecting records directly from the 
physician in addition to the records that they collect from the supplier.  
In response to the third recommendation, CMS stated that it is 
committed to continuing education of providers and suppliers about 
Medicare clinical coverage criteria for power wheelchairs.  Not only 
have CMSs contractors provided education, but also CMS conducted an 
educational outreach call and published educational materials in 2010.  
In response to the fourth recommendation, CMS stated that it will share 
OIG-provided information with Recovery Auditors and MACs for 
appropriate followup.  For the full text of CMSs comments, see 
Appendix E.  
 
 
 
 
 
 
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 ARPE PC EO NM DM IEXN ~D AA  T I O N S  
Clinical Coverage Criteria for Selected Power Wheelchairs 
This appendix is adapted from the National Coverage Determination 
(NCD) for Mobility-Assistive Equipment and the Local Coverage 
Determination (LCD) for Power Mobility Devices.  Information from the 
NCD has been incorporated in the LCDs, and we have included only the 
sections that are relevant to our evaluation.  Full copies of these policies 
from all durable medical equipment regions can be found by searching 
the CMS Web site at 
http://www.cms.gov/mcd/search.asp?clickon=search. 
Basic Coverage Criteria 
All of the following basic criteria (A C) must be met for a power 

mobility device (Healthcare Common Procedure Coding System 
(HCPCS) codes K0800 K0898) to be covered.80  Additional coverage 

criteria for specific devices are listed below. 
A)  The patient has a mobility limitation that significantly impairs 
his/her ability to participate in one or more mobility-related activities of 
daily living (MRADLs), such as using the toilet, feeding, dressing, 
grooming, and bathing in customary locations in the home.  A mobility 
limitation is one that: 
  prevents the patient from accomplishing a MRADL entirely; or 
  places the patient at reasonably determined heightened risk of 
morbidity or mortality secondary to the attempts to perform a 
MRADL; or 
  prevents the patient from completing a MRADL within a reasonable 
timeframe. 
B)  The patients mobility limitation cannot be sufficiently and safely 
resolved by the use of an appropriately fitted cane or walker. 
C)  The patient does not have sufficient upper extremity function to  
self-propel an optimally configured manual wheelchair in the home to 
perform MRADLs during a typical day. 
  Limitations of strength, endurance, range of motion, or coordination; 
presence of pain or deformity; and absence of one or both upper 
extremities are relevant to the assessment of upper extremity 
function. 
 
80 CMS does not cover HCPCS codes K0865K0898. 
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A P P E N D I X   A  
  An optimally configured manual wheelchair is one with an 
appropriate wheelbase, device weight, seating options, and other 
appropriate nonpowered accessories. 
Power Wheelchairs (HCPCS codes K0813 K0898) 

A power wheelchair is covered if: 
a.  All of the basic coverage criteria (A C) are met;  

b.  The patient does not meet coverage criteria for a power-operated 
vehicle;  
c.  Either criterion J or K[81] (see below) is met;  
d.  Criteria L, M, N, and O (see below) are met; and 
e.  Any coverage criteria pertaining to the specific wheelchair type (see 
below) are met. 
J)  The patient has the mental and physical capabilities to safely 
operate the power wheelchair that is provided; or 
K)  If the patient is unable to safely operate the power wheelchair, the 
patient has a caregiver who is unable to adequately propel an optimally 
configured manual wheelchair, but is available, willing, and able to 
safely operate the power wheelchair that is provided; and 
L)  The patients weight is less than or equal to the weight capacity of 
the power wheelchair that is provided. 
M)  The patients home provides adequate access between rooms, 
maneuvering space, and surfaces for the operation of the power 
wheelchair that is provided. 
N)  Use of a power wheelchair will significantly improve the patients 
ability to participate in MRADLs, and the patient will use it in the 
home.  For patients with severe cognitive and/or physical impairments, 
participation in MRADLs may require the assistance of a caregiver. 
O)  The patient has not expressed an unwillingness to use a power 
wheelchair in the home. 
 
81 Criteria DI apply to a different type of power mobility device. 
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A P P E N D I X   A  
Standard Power Wheelchairs    
Medicare covers standard power wheelchairs (HCPCS code K0823) if all 
of the power wheelchair coverage criteria are met and the beneficiary 
weighs less than 301 pounds. 
Complex Rehabilitation Power Wheelchairs 
Group 2 single power option (HCPCS codes K0835K0840).[82]  Medicare 
covers such wheelchairs if all of the power wheelchair coverage criteria 
are met and if criterion 1 or 2 is met and criterion 3 is met.   
1.  The beneficiary requires a drive control interface other than a hand- 
or chin-operated standard proportional joystick (examples include 
but are not limited to head control, sip and puff, switch control).   
2.  The beneficiary meets coverage criteria for a power tilt or a power 
recline seating system (see Appendix B), and the system is being 
used on the wheelchair. 
3.  The beneficiary has had a specialty evaluation performed by a 
licensed/certified medical professional, such as a physical therapist 
(PT) or occupational therapist (OT), or physician who has specific 
training and experience in rehabilitation wheelchair evaluations, 
and this specialty evaluation documents the medical necessity for 
the wheelchair and its special features.  The PT, OT, or physician 
may have no financial relationship with the supplier. 
Group 2 multiple power option (HCPCS codes K0841K0843).  Medicare 
covers such wheelchairs if all of the power wheelchair coverage criteria 
are met and if criterion 1 or 2 is met and criterion 3 is met. 
1.  The beneficiary meets coverage criteria for a power tilt and recline 
seating system (see Appendix B), and the system is being used on the 
wheelchair. 
2.  The beneficiary uses a ventilator mounted on the wheelchair. 
3.  The beneficiary has had a specialty evaluation performed by a 
licensed/certified medical professional, such as a PT or OT, or a 
physician who has specific training and experience in rehabilitation 
wheelchair evaluations, and this specialty evaluation documents the 
medical necessity for the wheelchair and its special features.  The 
 
82 Group 1 power wheelchairs (HCPCS codes K0813K0816) are not included in this 
review. 
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A P P E N D I X   A  
PT, OT, or physician may have no financial relationship with the 
supplier. 
Group 3 with no power options (HCPCS codes K0848 K0855).  Medicare 

covers such wheelchairs if all of the power wheelchair coverage criteria 
are met; the beneficiarys mobility limitation is due to a neurological 
condition, myopathy, or congenital skeletal deformity; and the 
beneficiary has had a specialty evaluation performed by a 
licensed/certified medical professional, such as a PT or OT, or a 
physician who has specific training and experience in rehabilitation 
wheelchair evaluations, and this specialty evaluation documents the 
medical necessity for the wheelchair and its special features.  The PT, 
OT, or physician may have no financial relationship with the supplier. 
Group 3 with single power option (HCPCS codes K0856K0860) or with 
multiple power options (HCPCS codes K0861K0864).  Medicare covers 
such wheelchairs if all of the power wheelchair coverage criteria are 
met; the beneficiarys mobility limitation is due to a neurological 
condition, myopathy, or congenital skeletal deformity; and the Group 2 
single power option or multiple power options are met.  
 
OEI-04-09-00260    MOST MEDICARE POWER WHEELCHAIRS DID NOT MEET MEDICAL NECESSITY GUIDELINES  35   
   
 A P P E N D I X ~ B  
Clinical Coverage Criteria for Selected Power Wheelchair Power 
Options and Accessories  
This appendix is adapted from the Local Coverage Determination (LCD) 
for Wheelchair Options/Accessories.  Full copies of this policy from all 
durable medical equipment regions can be found by searching the CMS 
Web site at http://www.cms.gov/mcd/search.asp?clickon=search. 
Arm of Chair 
Adjustable arm height option (E0973, K0017, K0018, K0020) is covered 
if the beneficiary requires an arm height that is different from that 
available using nonadjustable arms and the beneficiary spends at least 
2 hours per day in the wheelchair. 
An arm trough (E2209) is covered if the beneficiary has quadriplegia, 
hemiplegia, or uncontrolled arm movements. 
Footrest/Legrest 
Elevating legrests (E0990, K0046, K0047, K0053, K0195) are covered if: 
1.  the beneficiary has a musculoskeletal condition or a cast or brace 
that prevents 90-degree flexion at the knee; or 
2.  the beneficiary has significant edema of the lower extremities that 
requires having an elevating legrest; or 
3.  the beneficiary meets the criteria for and has a reclining back on the 
wheelchair.  
Nonstandard Seat Frame Dimensions 
A nonstandard seat width and/or depth for a manual wheelchair 
(E2201 E2204) is covered only if the beneficiarys dimensions justify the 

need. 
Batteries/Chargers 
Up to two batteries (E2361, E2363, E2365, E2371, K0731, K0733) at 
any one time are allowed if required for a power wheelchair. 
A nonsealed battery (E2360, E2362, E2364, E2372) will be denied as not 
medically necessary. 
A dual-mode battery charger (E2367) is not medically necessary; when 
it is provided as a replacement, payment is based on the allowance for 
the least costly medically appropriate alternative, E2366. 
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A P P E N D I X   B  
Power Tilt and/or Recline Seating Systems (E1002 E1010): 

A power seating systemtilt only, recline only, or combination tilt and 
reclinewith or without power elevating legrests will be covered if 
criteria 1 and 2 are met and if criterion 3, 4, or 5 is met: 
1.  the beneficiary meets all the coverage criteria for a power wheelchair 
described in the LCD for Power Mobility Devices; and 
2.  a specialty evaluation performed by a licensed/certified medical 
professional, such as a PT or OT or physician who has specific 
training and experience in rehabilitation wheelchair evaluations of 
the beneficiarys seating and positioning needs.  The PT, OT, or 
physician may have no financial relationship with the supplier; and 
3.  the beneficiary is at high risk for development of a pressure ulcer 
and is unable to perform a functional weight shift; or 
4.  the beneficiary utilizes intermittent catheterization for bladder 
management and is unable to independently transfer from the 
wheelchair to bed; or 
5.  the power seating system is needed to manage increased tone or 
spasticity.   
Power Wheelchair Drive Control Systems 
An attendant control is covered in place of a beneficiary-operated drive 
control system if the beneficiary meets coverage criteria for a 
wheelchair, is unable to operate a manual or power wheelchair, and has 
a caregiver who is unable to operate a manual wheelchair but is able to 
operate a power wheelchair. 
Other Power Wheelchair Accessories 
An electronic interface (E2351) to allow a speech-generating device to be 
operated by the power wheelchair control interface is covered if the 
beneficiary has a covered speech-generating device.  
Miscellaneous Accessories 
An antirollback device (E0974) is covered if the beneficiary propels 
himself/herself and needs the device because of ramps. 
A safety belt/pelvic strap (E0978) is covered if the beneficiary has weak 
upper body muscles, upper body instability, or muscle spasticity that 
requires use of this item for proper positioning. 
One example (not all-inclusive) of a covered indication for swingaway, 
retractable, or removable hardware (E1028) would be to move the 
OEI-04-09-00260    MOST MEDICARE POWER WHEELCHAIRS DID NOT MEET MEDICAL NECESSITY GUIDELINES  37   
   
A P P E N D I X   B  
component out of the way so that the beneficiary could perform a slide 
transfer to a chair or bed. 
A manual fully reclining back option (E1226) is covered if the 
beneficiary has one or more of the following conditions: 
1.  The beneficiary is at high risk for development of a pressure ulcer 
and is unable to perform a functional weight shift; or 
2.  The beneficiary utilizes intermittent catheterization for bladder 
management and is unable to independently transfer from the 
wheelchair to the bed. 
 
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 A P P E N D I X ~ C  
 
Table C-1:  Population and Sample Sizes by Stratum, First Half of 2007 
Population  Sample 
 Stratum  Definition  Claims  Expenditures  Suppliers  Claims  Expenditures  Suppliers 
Standard power wheelchair 
1  claims* by low-volume suppliers  7,223  $28,949,132  2,352  125  $499,152  124 
Standard power wheelchair 
2  claims* 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+ 
*  Healthcare Common Procedure Coding System (HCPCS) code K0823. 
** HCPCS codes K0835K0864. 
+ Suppliers figures do not sum to totals because of overlap (some suppliers in our sample provided 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 ~ D  
Table D-1:  Estimates and Confidence Intervals for Power Wheelchair Error Rates, First Half of 2007 
Sample  95-Percent 
Estimate Description  Size  Point Estimate  Confidence Interval 
All Power Wheelchairs 
Wheelchair was medically unnecessary   364  8.9%  5.7%13.5% 
Beneficiary needed a manual wheelchair, cane, or walker   364  1.6%  0.5%5.0% 
Beneficiary needed a different power wheelchair   364  7.3%  4.5%11.5% 
Beneficiary needed a less expensive power wheelchair   364  0.9%  0.6%1.4% 
Beneficiary needed a more expensive power wheelchair  364  3.0%  1.4%6.3% 
Reviewer could not determine specific power wheelchair that 
beneficiary needed  364  3.4%  1.6%7.2% 
Claim was insufficiently documented  364  51.7%  44.5%58.7% 
Claim was undocumented   364  0.1%  0.02%0.9% 
No errors  364  39.3%  32.6%46.5% 
     Total errors  364  60.7%  53.5%67.4% 
Standard Power Wheelchairs:  All Suppliers 
Wheelchair was medically unnecessary   240  7.8%  4.6%12.9% 
Beneficiary needed a manual wheelchair, cane, or walker  240  1.7%  0.5%5.3% 
Beneficiary needed a more expensive power wheelchair  240  2.8%  1.16%6.5% 
Reviewer could not determine specific power wheelchair that 
beneficiary needed  240  3.3%  1.5%7.5% 
Claim was insufficiently documented  240  53.1%  45.4%60.6% 
Claim was undocumented   240  0.1%  0.02%1.0% 
No errors   240  39.0%  31.9%46.7% 
     Total errors  240  61.0%  53.3%68.2% 
Standard Power Wheelchairs:  Low-Volume Suppliers 
     Total errors  120  65.8%  56.9%73.8% 
Standard Power Wheelchairs:  High-Volume Suppliers 
     Total errors  120  60.0%  51.0%68.4% 
Complex Rehabilitation Power Wheelchairs 
Wheelchair was medically unnecessary   124  24.2%  17.5%32.4% 
Beneficiary needed a manual wheelchair  124  0.8%  0.1%5.4% 
Beneficiary needed a less expensive power wheelchair   124  12.9%  8.1%19.9% 
Beneficiary needed a more expensive power wheelchair  124  5.7%  2.7%11.3% 
Reviewer could not determine specific power wheelchair that 
beneficiary needed  124  4.8%  2.1%10.3% 
Claim was insufficiently documented  124  32.3%  24.7%40.8% 
Claim was undocumented   124  0%  0%2.9% 
No errors   124  43.6%  35.2%52.3% 
     Total errors  124  56.5%*  47.7%64.8% 
* Point estimate is rounded from 56.45% to 56.5%.  
Source:  Office of Inspector General (OIG) medical record review of Medicare power wheelchair claims, 2010. 
 
 
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A P P E N D I X   D  
 
Table D-2:  Estimates and Confidence Intervals for Comparisons of Error Rates by Power 
Wheelchair Type, First Half of 2007 
Sample  Point  95-Percent 
Estimate Description  Size  Estimate  Confidence Interval  P-Value 
Comparisons of Standard Versus Complex Rehabilitation Power Wheelchairs 
Difference in percentage of power 
wheelchairs that were medically unnecessary    364  16.4%*  8.0%24.9%  0.0002 
Difference in percentage of power 
wheelchairs with claims that were 
insufficiently documented or were 
undocumented   364  20.9%**  9.8%32.1%  0.0003 
* Twenty-four percent of complex rehabilitation power wheelchairs were medically unnecessary and 8 percent of standard power wheelchairs 
were medically unnecessary. 
** Fifty-three percent of claims for standard power wheelchairs were insufficiently documented and 32 percent of claims for complex 
rehabilitation power wheelchairs were insufficiently documented. 
Source:  OIG medical record review of Medicare power wheelchair claims, 2010.   
 
 
 
 
Table D-3:  Estimates and Confidence Intervals for Inappropriate Payments for Power 
Wheelchairs With Errors, First Half of 2007 
Sample  95-Percent Confidence 
Estimate Description  Size  Point Estimate*  Interval* 
All Power Wheelchairs 
Insufficient documentation  364  $93,227,220  $80,467,932$105,986,508 
     Total errors  364  $95,182,002  $82,376,901$107,987,103 
Standard Power Wheelchairs:  All Suppliers 
     Total errors  240  $89,983,213  $77,245,694$102,720,732 
Complex Rehabilitation Power Wheelchairs 
     Total errors  124  $5,198,789  $3,884,930$6,512,648 
* Dollar figures are rounded to the nearest whole dollar. 
Source:  OIG medical record review of Medicare power wheelchair claims, 2010. 
 
 
 
 
 
 
 
 
 
 
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A P P E N D I X   D  
 
Table D-4:  Estimates and Confidence Intervals for Error Rates and Inappropriate Payments 
for Power Options and Accessories, First Half of 2007 
Sample  Point  95-Percent 
Estimate Description  Size  Estimate  Confidence Interval 
Power option or accessory was medically unnecessary 
or insufficiently documented  556  19.4%  14.5%25.6% 
Power option or accessory was medically unnecessary  556  3.8%  2.2%6.3% 
Power option or accessory was insufficiently 
documented  556  15.7%  11.2%21.5% 
One or more options or accessories provided with 
power wheelchair were medically unnecessary  108  13.9%  8.6%21.6% 
Power option or accessory error  556  $1,908,688  $856,598$2,960,778 
Note:  Dollar figures are rounded to the nearest whole dollar. 
Source:  OIG medical record review of Medicare power wheelchair claims, 2010. 
 
 
 
 
 
Table D-5:  Estimates and Confidence Intervals for Types of Errors in Physicians Records 
for Claims With No Errors Based on Suppliers Records, First Half of 2007 
Sample  Point  95-Percent 
Estimate Description  Size  Estimate  Confidence Interval 
Claims for power wheelchairs that were medically 
necessary based on supplier record but medically 
unnecessary based on physician record  121  6.9%  2.4%18.2% 
Claims for power wheelchairs that were medically 
necessary based on supplier record but insufficiently 
documented based on physician record  121  62.1%  49.1%73.6% 
Claims for power wheelchairs that were medically 
necessary based on supplier record but undocumented 
based on physician record  121  8.7%  3.7%19.1% 
Claims for power wheelchairs that were medically 
necessary based on supplier record but medically 
unnecessary, insufficiently documented, or undocumented 
65.7%86.4% 
based on physician record  121  77.7% 
Source:  OIG medical record review of Medicare power wheelchair claims, 2010. 
 
 
 
 
 
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AP P AE NP DP IE XN  DD I  X ~ D  
 
Table D-6:  Estimates and Confidence Intervals for Combined Error Rate Across Three 
Reports, First Half of 2007 
Point  95-Percent Confidence 
Estimate Description  Sample Size  Estimate  Interval 
Combined error rateclaims reviewed in all three 
reports  339  79.8%  72.9%85.4% 
Combined error rateclaims reviewed in at least 
one report  365  78.9%  72.2%84.3% 
Sources:  OIG medical record review of Medicare power wheelchair claims, 2010; HHS OIG, Miscoded Claims for Power Wheelchairs in the 
Medicare Program, OEI-04-07-00403, July 2009; and HHS OIG, Medicare Power Wheelchair Claims Frequently Did Not Meet Documentation 
Requirements, OEI-04-07-00401, December 2009. 
 
 
 
 
 
 
 
 
 
 
 
 
OEI-04-09-00260    MOST MEDICARE POWER WHEELCHAIRS DID NOT MEET MEDICAL NECESSITY GUIDELINES  43  A  P  PEN  D  x  E 

Agency Comments 
...."".or...'" 
(~.# 
DEPARl'MENT OF HEACfH & HUMAN SERVlCFS  Centers lor Medicare & Medicaid Services 
Ad",inistrator 
Washington. DC 20201 
APR  2 7 2011 
DATE: 
TO:  Daniel R. Levinson 
Inspector General 
FROM:  Donald M. Berwick. M.D. 
Administrator 
SUBJECT:  Office ofInspector General (OIG) Draft Report: "Most Power 
Wheelchairs in the Medicare Program Did Not Meet Medical Necessity 
Guidelines" (OEl-04-09.Q0260) 
Thank you for the opportunity to review and comment on the above OlG draft report. 
The Centers for Medicare & Medicaid Services (eMS) appreciates the time and resources 
DIG has invested in determining the extent to wbich Medicare improperly paid claims for 
powerwheelcbairs. eMS is keenly focused on tbe issues related to power wheelchairs in 
the Medicare program. We appreciate DIG's work in this area. Since 2009. OlG has 
issued two reports based on the same sample of claims used in this study that assessed 
compliance wi th different Medicare requirements for power wheelchairs. Across the 
three reports, the 010 found that 80 percent of power wheelchairs provided in the first 
half of2007 did not meet Medicare requirements. This particular study found that 61 
percent ofpower wheelchair claims were not medically necessary or lacked sufficient 
documentation to determine medical necessity. eMS understands that inadequate and/or 
insufficient documentation is a significant problem associated with power wheelchair 
claims. 
As mentioned in the report, eMS is actively engaged in improving provider and supplier 
compliance with Medicare's power wheelchair requirements. In January 2011, eMS 
updated the payment policy for power wheelchairs, eliminating the up-front purchase 
option and keeping the rent-to-own option. Previously, Medicare allowed for either an 
up-front purchase or a rental period that would lead to ownership after 13 months. The 13 
month period allows additional opportunities for eMS to potentially conduct review on 
power wheelchair claims. 
The CMS continues to support efforts to reduce improper power wheelchair payments, 
including increased prepayment reviews of power wheelchairs. Moreover, eMS plans to 
pursue additional provider and supplier education to ensure suppliers and prescribing 
physicians understand Medicare's coverage and documentation requirements for power 
wheelchairs. 
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A P P E N D I X   E  
 
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A P P E N D I X   E  
 
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 A C K N O W L E D G M E N T S  
This report was prepared under the direction of Dwayne Grant, 
Regional Inspector General for Evaluation and Inspections in the 
Atlanta regional office, and Sarah Ambrose and Jaime Durley, Deputy 
Regional Inspectors General.   
Other principal Office of Evaluation and Inspections staff from the 
Atlanta regional office who contributed to the report include  
Holly Williams; central office staff who contributed include  
Berivan Demir Neubert, Kevin Farber, and Scott Manley.  
 
OEI-04-09-00260    MOST MEDICARE POWER WHEELCHAIRS DID NOT MEET MEDICAL NECESSITY GUIDELINES  48   
   
Office of Inspector General 
http://oig.hhs.gov 
 
The mission of the Office of Inspector General (OIG), as mandated by Public Law 95-452, as 
amended, is to protect the integrity of the Department of Health & Human Services (HHS) 
programs, as well as the health and welfare of beneficiaries served by those programs.  This 
statutory mission is carried out through a nationwide network of audits, investigations, and 
inspections conducted by the following operating components: 
Office of Audit Services 
The Office of Audit Services (OAS) provides auditing services for HHS, either by conducting 
audits with its own audit resources or by overseeing audit work done by others.  Audits 
examine the performance of HHS programs and/or its grantees and contractors in carrying 
out their respective responsibilities and are intended to provide independent assessments of 
HHS programs and operations.  These assessments help reduce waste, abuse, and 
mismanagement and promote economy and efficiency throughout HHS. 
Office of Evaluation and Inspections 
The Office of Evaluation and Inspections (OEI) conducts national evaluations to provide 
HHS, Congress, and the public with timely, useful, and reliable information on significant 
issues.  These evaluations focus on preventing fraud, waste, or abuse and promoting 
economy, efficiency, and effectiveness of departmental programs.  To promote impact, OEI 
reports also present practical recommendations for improving program operations.  
Office of Investigations 
The Office of Investigations (OI) conducts criminal, civil, and administrative investigations 
of fraud and misconduct related to HHS programs, operations, and beneficiaries.  With 
investigators working in all 50 States and the District of Columbia, OI utilizes its resources 
by actively coordinating with the Department of Justice and other Federal, State, and local 
law enforcement authorities.  The investigative efforts of OI often lead to criminal 
convictions, administrative sanctions, and/or civil monetary penalties. 
Office of Counsel to the Inspector General 
The Office of Counsel to the Inspector General (OCIG) provides general legal services to 
OIG, rendering advice and opinions on HHS programs and operations and providing all 
legal support for OIGs internal operations.  OCIG represents OIG in all civil and 
administrative fraud and abuse cases involving HHS programs, including False Claims Act, 
program exclusion, and civil monetary penalty cases.  In connection with these cases, OCIG 
also negotiates and monitors corporate integrity agreements.  OCIG renders advisory 
opinions, issues compliance program guidance, publishes fraud alerts, and provides other 
guidance to the health care industry concerning the anti-kickback statute and other OIG 
enforcement authorities.