Department of Health and Human Services

OFFICE OF 

INSPECTOR GENERAL 

 

MEDICARE POWER WHEELCHAIR 

CLAIMS FREQUENTLY DID NOT 

MEET DOCUMENTATION 

REQUIREMENTS 

 

Daniel R. Levinson 

Inspector General 

December 2009 

OEI-04-07-00401 
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 and Human Services 

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The Office of Evaluation and Inspections (OEI) conducts national evaluations to provide 

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enforcement authorities. 
 

 EXECUTIVE SUMMARY 

OBJECTIVE

To determine the extent to which standard and complex rehabilitation 

power wheelchair claims met Medicare documentation requirements 

during the first half of calendar year 2007. 

BACKGROUND 

Medicare beneficiaries are eligible to receive power wheelchairs under 

Medicare Part B coverage of durable medical equipment. Beneficiaries 

receive power wheelchairs from suppliers, which bill the Medicare 

program for reimbursement. The supplier receives the power 

wheelchair prescription, along with documentation from the 

beneficiary’s medical record to support the power wheelchair’s necessity, 

from the prescribing physician. Based on the prescription, the supplier 

recommends a specific power wheelchair for the beneficiary. The 

physician must then review and approve the supplier’s 

recommendation. 

Standard power wheelchairs accounted for nearly three-quarters of 

Medicare’s power wheelchair claims and expenditures in the first half of 

2007. These power wheelchairs provide basic, daily mobility. Complex 

rehabilitation power wheelchairs accounted for less than 7 percent of 

power wheelchair expenditures during the first half of 2007. To receive 

a complex rehabilitation power wheelchair, the beneficiary’s mobility 

limitation must result from a neurological condition, muscle disease, or 

skeletal deformity. Complex rehabilitation power wheelchairs can be 

upgraded with power options and other electronic features to 

accommodate beneficiaries’ mobility needs.

To receive Medicare payment for a power wheelchair, suppliers must 

meet all documentation requirements included in the power wheelchair 

Local Coverage Determinations (LCD). The power wheelchair LCDs 

published by each of Medicare’s four Durable Medical Equipment 

Medicare Administrative Contractors are identical. The LCD requires 

that suppliers maintain a variety of documents that support the 

beneficiary’s need for, and the appropriateness of, the provided power 

wheelchair. Specifically, the supplier must have the power wheelchair 

prescription, supporting documentation from the beneficiary’s medical 

record, the specialty evaluation report, the detailed product description, 

the home assessment report, and proof of delivery. For many of these 

documents, the LCD includes requirements related to the documents’ 

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EXECUTIVE SUMMARY 

contents and the timeframes within which the supplier should create or 

receive the documents. 

We selected a random sample of 375 claims for standard and complex 

rehabilitation power wheelchairs supplied to Medicare beneficiaries in 

the first half of 2007. We then collected documents required by 

Medicare from the power wheelchair suppliers, determined the extent to 

which claims met documentation requirements, and projected our 

results nationally. 

FINDINGS 

Three out of five claims for standard and complex rehabilitation 

power wheelchairs did not meet Medicare documentation 

requirements during the first half of 2007. We found that 60 percent 

of Medicare claims for standard and complex rehabilitation power 

wheelchairs that beneficiaries received in the first half of 2007 did not 

meet one or more documentation requirements. Power wheelchair 

claims that did not meet all documentation requirements accounted for 

$112 million in improper Medicare payments, out of $189 million total 

allowed by Medicare during the 6-month period. Beneficiaries were 

responsible for paying $22 million of this amount. Power wheelchair 

claims were more likely to meet some documentation requirements than 

others. Error rates ranged from 1 percent of claims for which the 

suppliers did not submit proof of delivery to 40 percent of claims for 

which the supporting documentation and detailed product descriptions 

were not submitted or were incomplete. Two out of five power 

wheelchair claims had multiple errors. In addition, suppliers submitted 

incomplete documents almost three times as often as they failed to 

submit required documents. The specialty evaluation report was one of 

the documents most often not submitted by complex rehabilitation 

power wheelchair suppliers. 

Medicare documentation error rates varied by power wheelchair type 

and supplier volume during the first half of 2007. Complex 

rehabilitation power wheelchair claims had a higher documentation 

error rate (93 percent) than standard power wheelchair claims 

(58 percent). However, because suppliers provided over 13 times more 

standard than complex rehabilitation power wheelchairs, 

documentation errors for standard power wheelchair claims resulted in 

more improper payments than claims for complex rehabilitation power 

wheelchairs ($97 million and $15 million, respectively). Standard power 

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EXECUTIVE SUMMARY 

wheelchair claims submitted by low-volume suppliers had a higher 

documentation error rate (72 percent) than those from high-volume 

suppliers (55 percent). However, claims that high-volume suppliers 

submitted accounted for more improper payments than did claims 

submitted by low-volume suppliers ($77 million and $20 million, 

respectively). 

RECOMMENDATIONS 

Power wheelchair suppliers must maintain specific documentation to 

support beneficiaries’ need for the provided power wheelchairs. 

Medicare policy requires that suppliers and prescribing physicians 

coordinate to ensure that beneficiaries receive the most appropriate 

equipment to accommodate their mobility needs. 

We found that 60 percent of claims for standard and complex 

rehabilitation power wheelchairs that beneficiaries received in the first 

half of 2007 did not meet all Medicare documentation requirements. 

These claims accounted for $112 million in improper Medicare 

payments, out of the $189 million total allowed by Medicare. 

Beneficiaries were responsible for paying $22 million of this amount. 

We also found that complex rehabilitation power wheelchair claims had 

a higher documentation error rate than standard power wheelchair 

claims. Standard power wheelchair claims submitted by low-volume 

suppliers had a higher documentation error rate than those from 

high-volume suppliers. 

Based on these findings, we recommend that the Centers for Medicare 

& Medicaid Services (CMS): 

Improve compliance with Medicare’s power wheelchair 

documentation requirements. CMS should consider the following 

methods for improving compliance: 

 conduct additional reviews of power wheelchair claims, 

 recover overpayments from suppliers that do not meet 

documentation requirements and consider further action as 

appropriate, and

 increase education for suppliers and prescribing physicians about 

documentation requirements. 

Take appropriate action on sampled claims found to be in error. 

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OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS iv 

EXECUTIVE SUMMARY 

AGENCY COMMENTS AND OFFICE OF INSPECTOR GENERAL 

RESPONSE 

CMS concurred with both of our recommendations. CMS noted that it 

has multiple efforts underway or planned that align with each 

suggested method to improve compliance with Medicare’s power 

wheelchair documentation requirements. CMS will also forward the 

sampled claims we found to be in error to the appropriate contractors to 

identify and recover overpayments. We will forward information on 

these claims to CMS under separate cover. 

 
 TABLE OF CONTENTS 

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

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

FINDINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

 Three out of five claims for standard and complex 

rehabilitation power wheelchairs did not meet Medicare 

documentation requirements during the first half of 2007 . . . . . . 14 

 Medicare documentation error rates varied by power 

 wheelchair type and supplier volume during the 

 first half of 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

 

RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 

 Agency Comments and Office of Inspector General Response . . . 24 

APPENDIXES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 

 A: Medicare’s Power Wheelchair Documentation Requirements . 26 

 B: Population and Sample Sizes by Stratum, First 

 Half of 2007 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 

 C: Incomplete Documentation Error Rates, First Half of 2007 . . 28 

 D: Estimates and Confidence Intervals. . . . . . . . . . . . . . . . . . . . . 29 

 E: Agency Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
 

 INTRODUCTION 

OBJECTIVE 

To determine the extent to which standard and complex rehabilitation 

power wheelchair claims met Medicare documentation requirements 

during the first half of calendar year 2007. 

BACKGROUND 

Between 1999 and 2003, Medicare payments for power wheelchairs 

increased approximately 350 percent, from $259 million to $1.2 billion, 

while overall Medicare program expenditures rose 28 percent.1 In 2005 

and 2006, the Centers for Medicare & Medicaid Services (CMS) revised 

its policies related to power wheelchair coverage and coding in response 

to numerous instances of fraud and abuse and the growth in Medicare 

power wheelchair expenditures.2 In 2007, approximately 173,300 

Medicare beneficiaries received power wheelchairs, at a total cost of 

$686 million.3

Medicare beneficiaries are eligible to receive power wheelchairs under 

Medicare Part B coverage of durable medical equipment (DME). Power 

wheelchairs are medically necessary for beneficiaries who cannot 

perform mobility-related activities of daily living using other mobilityassistive equipment, such as a cane, manual wheelchair, or poweroperated scooter.4, 5 Most beneficiaries who require power wheelchairs 

are unable to walk and have severe upper body weakness because of a 

neurologic or muscular condition.6 

Medicare beneficiaries receive power wheelchairs from DME suppliers, 

which bill the Medicare program for reimbursement. The supplier 

receives the power wheelchair prescription, along with documentation 

from the beneficiary’s medical record to support the power wheelchair’s 

1 71 Fed. Reg. 17021, 17022 (Apr. 5, 2006). 

2 CMS, Pub. No. 11272P, 2006 Fee Schedule Amounts for Power Mobility Devices Have 

Been Refined, November 2006. 

3 Office of Inspector General (OIG) analysis of CMS’s claims data, July 2008. 

4 Medicare National Coverage Determinations Manual, Section 280.3. Last modified in 

August 2005. 

5 Based on Medicare’s National Coverage Decision for Power Mobility Devices, mobilityrelated activities of daily living include toileting, feeding, dressing, grooming, and bathing 

in customary locations within the home. 

6 CMS’s Medicare Learning Network, Medicare Coverage of Power Mobility Devices: 

Power Wheelchairs and Power Operated Vehicles, April 2006. 

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INTRODUCTION 

necessity, from the prescribing physician.7 Based on the prescription, 

the supplier recommends a specific power wheelchair. The physician 

must then review and approve the supplier’s recommendation.8 

The beneficiary may choose to rent or purchase the power wheelchair.9 

However, most Medicare beneficiaries choose to purchase power 

wheelchairs.10

To receive reimbursement, suppliers submit claims to Medicare for 

power wheelchairs using Healthcare Common Procedure Coding System 

codes (procedure codes). Medicare determines the highest dollar 

amount that suppliers may be reimbursed for each procedure code (fee 

schedule amount). Medicare pays 80 percent of the fee schedule amount 

and the beneficiary is responsible for the remaining 20 percent. 

Power Wheelchair Types 

Medicare covers more than 650 power wheelchair models. Medicare 

assigns each model to 1 of Medicare’s 42 power wheelchair procedure 

codes (K0813–K0864).11 The procedure code assignment is based on the 

model’s performance, patient weight capacity, seat type, portability, and 

power seating system capability.12 

Two types of power wheelchairs, standard and complex rehabilitation, 

accounted for over 80 percent of all Medicare power wheelchair 

expenditures in the first half of 2007.13 These are covered by Medicare 

2 

7 Ibid. 

8 DME Medicare Administrative Contractors in jurisdictions A, B, C, and D, Local 

Coverage Determination (LCD) for Power Mobility Devices (hereinafter referred to as LCD 

for Power Mobility Devices). Available online at 

http://www.cms.hhs.gov/mcd/viewlcd.asp?lcd_id=23598&lcd_version=18&show=all. 

Accessed on October 16, 2007. 

9 Ibid. Medicare covers power wheelchairs under a capped rental arrangement. 

Medicare pays for a maximum of 13 continuous months of rental. Should a beneficiary 

choose to rent his or her power wheelchair, the supplier must transfer ownership to the 

beneficiary after the 13th month. 

10 In the first half of 2007, new power wheelchair purchases accounted for 95 percent of 

all Medicare power wheelchair expenditures. (OIG analysis of 2007 CMS claims data, 

January 2009.) 

11 Medicare has not assigned power wheelchairs to procedure codes K0817–K0819, 

K0832–K0834, and K0844–K0847. 

12 Statistical Analysis DME Regional Carrier, Power Mobility Device Coding Guidelines, 

August 3, 2006. 

13 OIG analysis of claims from the National Claims History file submitted under 

procedure codes K0823 and K0835–K0864 with dates of service from January 1 to June 30, 

2007, processed as of June 30, 2007. 

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INTRODUCTION 

under 27 procedure codes, which include 395 power wheelchair 

models.14

Standard power wheelchairs. In the first half of 2007, procedure code 

K0823 was the most frequently reimbursed power wheelchair type; it 

accounted for nearly three-quarters of Medicare’s power wheelchair 

claims and expenditures.15 As of July 2009, Medicare covered 98 power 

wheelchair models under procedure code K0823.16 We refer to K0823 

power wheelchairs as “standard power wheelchairs” in this report. 

Standard power wheelchairs are designed to provide basic, daily 

mobility for persons weighing less than 300 pounds and feature an 

automotive-style seat. These power wheelchairs cannot be upgraded 

with power options (e.g., a powered seating system) or other electronic 

features (e.g., a device to enable the user to control the chair by sipping 

and puffing through a straw).17 Medicare’s 2007 fee schedule amount 

for standard power wheelchairs was $4,024.18, 19

Complex rehabilitation power wheelchairs. Medicare payments for complex 

rehabilitation power wheelchairs accounted for less than 7 percent of 

power wheelchair claims and expenditures in the first half of 2007.20 

As of July 2009, Medicare covered 297 complex rehabilitation power 

wheelchair models under 26 procedure codes.21, 22 

Complex rehabilitation power wheelchairs can be upgraded with power 

options and other electronic features to accommodate beneficiaries’ 

specific mobility needs.23 For a beneficiary to receive many types of 

14 Medicare Pricing, Data Analysis, and Coding (PDAC) contractor, Motorized 

Wheelchair Product Classification List, July 16, 2009. 

15 OIG analysis of claims from the National Claims History file submitted under 

procedure code K0823 with dates of service from January 1 to June 30, 2007, processed as of 

June 30, 2007. 

16 Medicare PDAC contractor, op. cit. 

17 LCD for Power Mobility Devices, “Code Specific Requirements” and “Definitions.” 

18 DME, Prosthetics, Orthotics, and Supplies (DMEPOS) 2007 Fee Schedule. 

19 In January 2009, the fee schedule amount for standard power wheelchairs was 

reduced by 9.5 percent, to $3,641. 

20 OIG analysis of claims from National Claims History file submitted under procedure 

codes K0835–K0864 with dates of service from January 1 to June 30, 2007, processed as of 

June 30, 2007. 

21 DMEPOS Supplier Quality Standards, August 2007, p. 11. Complex rehabilitation 

procedure codes are K0835–K0843 and K0848–K0864. 

22 Medicare PDAC contractor, op. cit. 

23 LCD for Power Mobility Devices, “Code Specific Requirements.” 

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INTRODUCTION 

complex rehabilitation power wheelchairs, the beneficiary’s mobility 

limitation must result from a neurological condition, muscle disease, or 

skeletal deformity.24 Medicare’s 2007 fee schedule amounts for complex 

rehabilitation power wheelchairs ranged from $4,132 to $11,965.25, 26 

Medicare Documentation Requirements for Power Wheelchairs 

Section 1833(e) of the Social Security Act states in part that “no 

payment shall be made to any provider . . . unless there has been 

furnished such information as may be necessary in order to determine 

the amounts due such provider.” The Social Security Act, Code of 

Federal Regulations, Medicare’s National Coverage Decision for Power 

Mobility Devices, and Medicare’s Local Coverage Determinations (LCD) 

for Power Mobility Devices specify the circumstances under which 

power wheelchairs are reasonable and necessary.27, 28 To meet coverage 

requirements, these guidances require that suppliers maintain a variety 

of documents that support the beneficiary’s need for, and the 

appropriateness of, the provided power wheelchair. 

For any item to be covered by Medicare, it must “meet all . . . applicable 

Medicare statutory and regulatory requirements.”29 Medicare requires 

the following documentation to support power wheelchair claims: 

 power wheelchair prescription, 

 supporting documentation from the beneficiary’s medical record 

(hereinafter “supporting documentation”), 

 specialty evaluation report (for complex rehabilitation power 

wheelchairs only), 

 detailed product description, 

4 

24 LCD for Power Mobility Devices, “Indications and Limitations of Coverage and/or 

Medical Necessity.” 

25 DMEPOS 2007 Fee Schedule. 

26 In January 2009, the fee schedule amounts were reduced by 9.5 percent, to between 

$3,739 and $10,828. 

27 See 42 U.S.C. § 1395m(a)(1)(E)(iv), § 1834(a)(1)(E)(iv) of the Social Security Act, 

42 CFR 410.38(c)(2), Medicare’s National Coverage Decision for Power Mobility Devices, 

and LCD for Power Mobility Devices. LCDs provide guidance to the public and the medical 

community within their jurisdictions. CMS requires that the power wheelchair LCDs be 

the same for each jurisdiction to ensure uniformity for DMEPOS suppliers that operate 

nationally. 

28 The term “power mobility device” refers to both power wheelchairs and power-operated 

vehicles, which are commonly referred to as scooters. LCD for Power Mobility Devices. 

29 LCD for Power Mobility Devices. 

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INTRODUCTION 

 home assessment report, and 

 proof of delivery.30

Each of these documents is described in more detail below. For many 

of these documents, the LCD includes requirements related to the 

documents’ contents and the timeframes within which the supplier 

should create or receive the documents. 

Prescription. Medicare requires suppliers to obtain the power wheelchair 

prescription from the physician who examined the beneficiary.31, 32 The 

supplier must receive the prescription within 45 days of the 

beneficiary’s examination date and before delivering the power 

wheelchair to the beneficiary.33 Power wheelchair prescriptions must 

include seven elements: 

1. beneficiary name, 

2. examination date, 

3. diagnoses and conditions that support the claim, 

4. item description, 

5. expected length of time the beneficiary will need the chair, 

6. prescribing physician signature, and 

7. prescription date. 

30 The LCD for Power Mobility Devices requires all listed documents, other than proof of 

delivery, which is required by 42 CFR § 424.57(c)(12). 

31 LCD for Power Mobility Devices, “Documentation Requirements.” In addition to being 

part of the power wheelchair LCD, this requirement is codified in the Social Security Act at 

section 1843(a)(1)(E)(iv) and is also found in the regulations issued by CMS at 42 CFR 

§ 410.38(c)(2)(ii). 

32 Section 302(a)(2) of the Medicare Prescription Drug, Improvement, and Modernization 

Act of 2003, P.L.No. 108-173, amended the Social Security Act to include section 

1834(a)(1)(E)(iv), requiring that a physician or other treating practitioner assess the 

beneficiary’s need for a power wheelchair during a face-to-face examination before writing a 

prescription. See 42 U.S.C. § 1395m(a)(1)(E)(iv); section 1843(a)(1)(E)(iv) of the Social 

Security Act. If a specialist, such as a physical or occupational therapist, performs the 

evaluation, a physician still must review the examination report and sign and date it to 

meet Medicare requirements. See LCD for Power Mobility Devices. 

33 See LCD for Power Mobility Devices. The 45-day period does not include the time 

required by the supplier to provide the power wheelchair to the beneficiary, as time may be 

required to assemble or adjust it to meet the specific needs of the beneficiary. 

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INTRODUCTION 

The supplier must document the date it receives the prescription using 

a date stamp or an equivalent method.34

Supporting documentation. The supplier must also receive documentation 

from the prescribing physician that supports the medical necessity for 

the power wheelchair.35 The supplier must receive the supporting 

documentation within 45 days after the physician’s examination of the 

beneficiary and before the power wheelchair’s delivery.36

The medical record from the beneficiary’s examination is often sufficient 

supporting documentation to demonstrate the medical necessity for the 

power wheelchair.37 However, the physician’s medical record notes 

from the examination must clearly indicate that the primary reason for

the visit was to assess the beneficiary’s need for a power wheelchair.

physician-completed form or letter of attestation may not serve as the 

supporting documentation. The supplier must document the date it 

receives the supporting documentation using a date stamp or an 

equivalent method.

 A 

38 

Specialty evaluation report. A beneficiary who receives a complex 

rehabilitation power wheelchair must receive a specialty evaluation, in 

addition to the physician’s initial examination. The specialty evaluation 

report must document the medical necessity for the power wheelchair 

and each recommended option and accessory. A medical professional 

with experience in rehabilitation power wheelchair evaluations, such as 

an occupational or physical therapist, must perform the specialty 

evaluation.39 

Detailed product description. Based on the physician’s prescription, the 

supplier determines the specific power wheelchair that is appropriate 

for the beneficiary. The supplier must prepare a detailed product 

description that lists the specific power wheelchair and all options and 

accessories. This document should include a procedure code, a 

34 LCD for Power Mobility Devices. 

35 See 42 CFR 410.38(c)(2)(iii); LCD for Power Mobility Devices, “Documentation 

Requirements.” 

36 Ibid. The 45-day period does not include the time required by the supplier to provide 

the power wheelchair to the beneficiary, as additional time may be required to make or 

adjust it to meet the specific needs of the beneficiary. 

37 Preamble to Final Rule: 42 CFR Part 410.38(c), p. 10. 

38 LCD for Power Mobility Devices. 

39 LCD for Power Mobility Devices, “Documentation Requirements.” 

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INTRODUCTION 

description, a fee schedule amount, and the charge for each item the 

supplier plans to bill.40 

The supplier is required to submit the detailed product description for 

the prescribing physician’s approval. The supplier must receive the 

signed and dated detailed product description from the physician before 

delivering the power wheelchair to the beneficiary. The supplier must 

document the date it receives the detailed product description using a 

date stamp or an equivalent method. 

Home assessment report. The supplier must perform an onsite home 

assessment before or during the power wheelchair’s delivery to verify 

that the beneficiary can adequately maneuver the chair in his or her 

home. The assessment should consider the home’s layout, surfaces, etc. 

The supplier must maintain a written report of the assessment.41 

Proof of delivery. The supplier must maintain documentation, such as a 

delivery slip or an invoice, to show that the power wheelchair was 

delivered to the beneficiary.42 

Appendix A contains a summary of Medicare’s power wheelchair 

documentation requirements. 

Prior Office of Inspector General Work 

OIG has conducted several evaluations of power wheelchairs in the 

Medicare program.43 In 2001, OIG evaluated suppliers’ compliance 

with power wheelchair documentation requirements. That report found 

that over half of reviewed claims paid in 2001 under the most frequen

reimbursed procedure code (K0011) at the time were missing 

documentation, had incomplete documentation, or had documentation 

that was dated after the claim’s date of service. CMS has since revised 

and added to Medicare’s power wheelchair documentation 

requirements. For example, in 2006, CMS replaced the Certificate of 

Medical Necessity with the requirement that suppliers obtain the 

tly 

40 Ibid. All options and accessories for power wheelchairs are billed as separate items. 

41 Ibid. 

42 42 CFR § 424.57(c)(12). Proof of delivery is required by one of the 26 application 

certification standards that every Medicare DMEPOS supplier must meet to obtain and 

retain its billing privileges. 

43 Department of Health and Human Services (HHS) OIG, A Comparison of Prices for 

Power Wheelchairs in the Medicare Program, OEI-03-03-00460, April 2004; HHS OIG, 

Medicare Payments for Power Wheelchairs, OEI-03-02-00600, April 2004; HHS OIG, A 

Comparison of Medicare Program and Consumer Internet Prices for Power Wheelchairs, 

OEI-04-07-00160, October 2007. 

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INTRODUCTION 

prescription and supporting documentation from the prescribing 

physician.44 

Office of Inspector General Power Wheelchair Evaluation Series 

OIG is conducting a series of evaluations of Medicare’s payments for 

power wheelchairs supplied to Medicare beneficiaries in the first half of 

2007. In addition to issuing this report, OIG issued separate reports on 

suppliers’ costs to purchase power wheelchairs and the services that 

suppliers performed in conjunction with providing the chairs, suppliers’ 

costs to purchase power wheelchair batteries, and miscoded power 

wheelchair claims.45 OIG also plans to issue a report on the 

appropriateness (e.g., the medical necessity) of power wheelchair claims. 

In addition to determining whether beneficiary medical records 

supported the medical necessity of the power wheelchair, OIG will 

determine whether documentation from the suppliers and prescribing 

physicians was consistent. 

METHODOLOGY 

Scope 

This evaluation focused on standard and complex rehabilitation power 

wheelchairs supplied to Medicare beneficiaries in the first half of 2007. 

We reviewed documentation for a random sample of 375 standard and 

complex rehabilitation power wheelchair claims to determine the extent 

to which the claims met documentation requirements from the LCD for 

Power Mobility Devices, as well as the proof-of-delivery requirement 

from Medicare’s supplier standards. 

We did not perform a medical record review to determine whether the 

supporting documentation or written report of the specialty evaluation 

submitted by suppliers supported the medical necessity of the power 

wheelchairs. In addition, we did not determine whether notes from the 

beneficiary examinations indicated that mobility examinations were the 

44 Prior to 2005, suppliers were required to submit a Certificate of Medical Necessity 

with power wheelchair claims. The Certificate of Medical Necessity collected information 

relating to the equipment ordered from the supplier and information on the beneficiary’s 

medical condition from the prescribing physician. CMS’s Medicare Learning Network, 

Medicare Coverage of Power Mobility Devices: Power Wheelchairs and Power Operated 

Vehicles, April 2006. 

45 HHS OIG, Power Wheelchairs in the Medicare Program: Supplier Acquisition Costs 

and Services, OEI-04-07-00400, August 2009; Supplier Acquisition Costs for Power 

Wheelchair Batteries in the Medicare Program (in progress); and Miscoded Claims for 

Power Wheelchairs in the Medicare Program, OEI-04-07-00403, July 2009. 

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reason for the visits. Finally, we did not determine whether specialty 

evaluations were performed by medical professionals with experience in 

complex rehabilitation power wheelchair evaluations. Appendix A 

distinguishes between the requirements that we reviewed and those 

that we did not review. 

Sample Selection 

Our population consisted of new, nonrental power wheelchair claims 

from CMS’s National Claims History DME Standard Analytical File 

with dates of service during the first half of 2007.46 We removed claims 

associated with suppliers that were inactive or whose billing privileges 

had been revoked and claims associated with suppliers or prescribing 

physicians that were under OIG investigation.47, 48 After removing 

these claims, the population from which we sampled included 93 

percent of standard and 91 percent of complex rehabilitation power 

wheelchair claims.49 We grouped the resulting population into three 

strata: 

1. standard power wheelchair claims submitted by low-volume 

suppliers (those that submitted fewer than 10 standard power 

wheelchair claims in the first half of 2007),50 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 9 

46 The final date to submit claims for power wheelchairs that were provided during the 

first half of 2007 was December 31, 2008. We analyzed claims CMS processed as of June 

30, 2007. Suppliers had submitted 79 percent of claims for power wheelchairs that were 

provided during the first half of 2007 at the time we selected our sample. 

47 We removed claims according to the suppliers’ status at the time that we selected the 

sample. 

48 Pursuant to 42 CFR § 424.520(a), to maintain Medicare billing privileges after initial 

enrollment, suppliers must comply with Medicare regulations and relevant Federal and 

State requirements. Pursuant to 42 CFR § 424.535, Medicare may revoke a supplier’s 

billing privileges because of a felony, noncompliance with enrollment requirements, etc. 

Pursuant to 42 CFR § 424.540, Medicare also may deactivate a supplier’s billing privileges 

when the supplier does not submit a claim for a full year or when the supplier fails to report 

a change to the information provided on the enrollment application. 

49 We removed 3,430 standard and 301 complex rehabilitation power wheelchair claims 

because of the suppliers’ Medicare enrollment status or ongoing investigations. After 

removing these, our population consisted of 43,133 standard and 3,001 complex 

rehabilitation power wheelchair claims. 

50 We divided the standard power wheelchair population by supplier volume based on the 

distribution of suppliers and claims. Twenty-five percent of suppliers received Medicare 

reimbursement for 10 or more standard power wheelchair claims during the first half of 

2007, and these claims accounted for 83 percent of all standard power wheelchair claims. 
 

INTRODUCTION 

2. standard power wheelchair claims submitted by high-volume 

suppliers (those that submitted 10 or more standard power 

wheelchair claims in the first half of 2007), and 

3. complex rehabilitation power wheelchair claims. 

We sampled 375 total claims by selecting simple random samples of 

125 claims from each stratum.51 Appendix B provides the number of 

claims, amount of Medicare expenditures, and number of suppliers for 

the population and sample, by stratum. 

Data Collection 

We asked suppliers to submit the following documents to support 

their power wheelchair claims: prescription, supporting 

documentation, specialty evaluation report (for complex rehabilitation 

chairs only), detailed product description, home assessment report, 

and proof of delivery. We also requested documentation identifying 

the dates the supplier received the prescription, supporting 

documentation, and the detailed product description from the 

prescribing physician. 

Before mailing the documentation requests, we asked representatives 

of three power wheelchair suppliers to review the request for clarity 

and familiarity of language. We made changes to the request based 

on their feedback. 

We obtained suppliers’ addresses from the National Supplier 

Clearinghouse data file. We mailed the documentation requests to 

the power wheelchair suppliers in our sample. We mailed up to three 

requests and telephoned nonresponding suppliers to ensure they had 

received the requests. We did not receive responses from suppliers of 

11 claims.52 Of these, the supplier of one claim did not respond, 

although we were able to verify the supplier’s receipt of our request. 

We considered this claim as lacking documentation and included it in 

our analysis. We excluded the remaining 10 claims from our sample 

because we could not contact the suppliers or verify that they received 

our request. Therefore, we used a total of 365 claims in our analysis, 

for a response rate of 97 percent. 

10 

51 All evaluations in the current OIG power wheelchair evaluation series use this sample. 

52 We referred suppliers that did not respond to our request to CMS and shared this 

information with OIG’s Office of Investigations. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS
 INTRODUCTION 

Data Analysis 

We determined whether suppliers submitted the requested 

documentation for the 365 claims. We reviewed the documentation to 

determine the extent to which they met Medicare documentation 

requirements. 

Prescription. We identified all claims for which the suppliers submitted 

prescriptions. For those that did, we determined whether the 

prescriptions included all seven required elements: beneficiary name, 

beneficiary examination date, diagnoses and conditions that support the 

claim, item description, expected length of time the beneficiary will need 

the chair, prescribing physician signature, and prescription date. 

We determined whether suppliers submitted documentation of the dates 

they received the prescriptions from the prescribing physicians. For 

claims that had these dates, we determined whether the suppliers 

received the prescriptions within 45 days after the beneficiary 

examinations. To make that determination, we compared the dates the 

suppliers received the prescriptions with the dates of the beneficiaries’ 

examinations (a required element on the prescription). We compared 

the dates the suppliers received prescriptions with the claims’ dates of 

service to determine whether the suppliers received the prescriptions 

before the chairs were delivered. 

Supporting documentation. We identified all claims for which suppliers 

submitted supporting documentation from the beneficiaries’ medical 

records. We did not count physician-completed forms or letters of 

attestation as supporting documentation because Medicare’s LCD states 

that these do not substitute for the beneficiaries’ medical records. 

We determined whether suppliers submitted documentation of the date 

they received the supporting documentation from the prescribing 

physicians. For claims that had these dates, we determined whether 

the suppliers received the supporting documentation within 45 days 

after the beneficiary examinations using the same approach as for the 

prescriptions. 

Specialty evaluation report. We identified complex rehabilitation power 

wheelchair claims for which the suppliers submitted specialty 

evaluation reports. 

Detailed product description. We identified all claims for which the 

suppliers submitted detailed product descriptions. We determined 

whether the detailed product description listed the specific power 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 11 
 

INTRODUCTION 

wheelchair base and all options and accessories for which the supplier 

billed Medicare. For each item the supplier billed, we determined 

whether the detailed product description included a procedure code, 

description, Medicare fee schedule amount, and supplier charge. 

We determined whether the prescribing physician approved the detailed 

product description by signing and dating it before the power 

wheelchair was delivered to the beneficiary. We also determined 

whether suppliers submitted documentation of the dates they received 

the detailed product descriptions from the prescribing physicians. 

Home assessment report. We identified all claims for which the suppliers 

submitted home assessment reports. We determined whether the home 

assessment was performed before or during the chair’s delivery. We 

also determined whether the home assessment report addressed the 

physical layout of the beneficiary’s home. 

Proof of delivery. We identified all claims for which the suppliers 

submitted proof of delivery. 

We identified all claims that did not meet one or more of the 

documentation requirements that we reviewed. We also distinguished 

between “document not submitted” errors and “incomplete document” 

errors. We considered a document to be incomplete if it did not meet all 

Medicare requirements (for example, if it was missing a required piece 

of information or was not received within the required timeframe). We 

projected error rates for these claims and compared the error rates by 

standard versus complex rehabilitation power wheelchairs and, for 

standard power wheelchairs, by supplier volume.53 

For claims that had errors, we calculated the expenditures (improper 

payments) using Medicare-allowed amounts from the National Claims 

History data. 

Limitations 

We did not review claims’ compliance with all the requirements from 

Medicare’s LCD for Power Mobility Devices. For example, we did not 

determine whether the supporting documentation or written report of 

the specialty evaluation supported the medical necessity of the chair. 

Therefore, our results may underestimate the documentation-related 

error rate. 

53 We used SAS and SUDAAN survey data analysis software to project our sample 

results nationally. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 12 
 

INTRODUCTION 

Standards 

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

Inspections” approved by the Council of the Inspectors General on 

Integrity and Efficiency. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 13 
  FINDINGS 

Three out of five claims for standard and 

complex rehabilitation power wheelchairs did 

not meet Medicare documentation requirements 

during the first half of 2007 

Sixty percent of claims for standard 

and complex rehabilitation power 

wheelchairs that Medicare 

beneficiaries received during the 

first half of 2007 did not meet one 

or more documentation requirement.54 Medicare requires suppliers to 

obtain a variety of documents that support the beneficiary’s need for, 

and the appropriateness of, the provided power wheelchairs. Suppliers 

must also have proof of the power wheelchair’s delivery. Claims that 

did not meet all documentation requirements accounted for $112 million 

in improper Medicare payments, out of $189 million total allowed by 

Medicare during the 6-month period. Beneficiaries were responsible for 

paying $22 million of this amount. 

Standard and complex rehabilitation power wheelchair claims were 

more likely to meet some documentation requirements than others. 

Two out of five power wheelchair claims had multiple errors. In 

addition, suppliers submitted incomplete documents almost three times 

as often as they failed to submit required documents. The specialty 

evaluation report was one of the documents most often not submitted by 

complex rehabilitation power wheelchair suppliers. 

Appendix C presents error rates for requirements related to the 

documents’ contents and the time frames within which the supplier 

should create or receive the documents (i.e., incomplete documentation 

errors). Appendix D provides the confidence intervals for estimates of 

all documentation error rates and associated improper payments. 

Standard and complex rehabilitation power wheelchair claims were more 

likely to meet some documentation requirements than others 

Power wheelchair claims varied in the extent to which they did not meet 

Medicare requirements for the prescription, supporting documentation, 

specialty evaluation report, detailed product description, home 

assessment report, and proof of delivery. Error rates ranged from 

1 percent of claims for which the suppliers did not submit proof of 

delivery to 40 percent of claims for which the supporting documentation 

and detailed product descriptions were not submitted or were 

incomplete. 

14 

54 Standard power wheelchairs accounted for approximately three-quarters of Medicare 

power wheelchair expenditures in the first half of 2007. Complex rehabilitation power 

wheelchairs accounted for 6 percent. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS
 

FINDINGS 

Table 1 presents the error rates for each documentation requirement 

and in total. 

Table 1: Medicare Documentation Error Rates for Standard and 

Complex Rehabilitation Power Wheelchair Claims, First Half of 2007 

Documentation Requirement Error Rate 

Supporting documentation 40% 

Detailed product description 40% 

Prescription 32% 

Specialty evaluation report* 2% 

Home assessment report 18% 

Proof of delivery 1% 

(Overlapping errors) (73%) 

 Total 60% 

* Requirement does not apply to standard power wheelchairs. Thirty percent of complex rehabilitation 

power wheelchair claims did not meet the specialty evaluation report requirement. 

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009. 

Supporting documentation. Forty percent of power wheelchair claims did 

not have complete supporting documentation, such as physician notes or 

test results, from the beneficiaries’ medical records. Instead of a 

Certificate of Medical Necessity, power wheelchair suppliers must 

obtain documentation from the beneficiary’s medical record that clearly 

supports the medical necessity for the power wheelchair from the 

prescribing physician.55 Claims that did not have complete supporting 

documentation resulted in $75 million in improper payments by 

Medicare and its beneficiaries. 

Although suppliers of only 2 percent of claims did not submit any 

supporting documentation, suppliers of another 38 percent of claims 

submitted supporting documentation that did not meet all of Medicare’s 

requirements. For example, the supporting documentation for 

20 percent of claims did not include the physician’s notes from the 

beneficiaries’ medical records. Instead, these claims were improperly 

supported by either physician-completed forms or letters of attestation. 

In addition, suppliers did not always meet the 45-day requirement. 

Specifically, suppliers of 9 percent of claims did not receive the 

55 We did not conduct a medical record review to determine whether this documentation 

supported the medical necessity of the power wheelchairs. OIG plans to issue a separate 

report on the appropriateness (e.g., the medical necessity) of power wheelchair claims. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 15 
 

FINDINGS 

documentation within 45 days after the beneficiary’s examination and, 

for 8 percent of claims, suppliers did not receive the documentation 

before the delivery date. Other claims did not include the date the 

supplier received the supporting documentation. For those that did, 

suppliers received the supporting documentation within a median of 

7 days after the beneficiary’s examination. However, the maximum 

amount of time was 405 days, approximately 14 months after the 

examination. 

Detailed product description. Forty percent of power wheelchair claims 

did not have a complete detailed product description. The detailed 

product description is the supplier’s recommendation of the specific 

power wheelchair and accessories that are appropriate for the 

beneficiary. The prescribing physician must approve the supplier’s 

recommendation before the chair is provided. Claims with missing or 

incomplete detailed product descriptions resulted in $74 million in 

improper payments by Medicare and its beneficiaries. 

Although suppliers of 14 percent of claims did not submit a detailed 

product description, suppliers of another 26 percent of claims submitted 

detailed product descriptions that did not meet all of Medicare’s 

requirements. Without a complete detailed product description, 

Medicare claim reviewers cannot determine whether the physician 

approved the supplier’s suggested power wheelchair and accessories 

before the beneficiary received his or her power wheelchair. 

For example, some detailed product descriptions did not include all 

items for which the supplier billed Medicare.56 In addition, detailed 

product descriptions did not always include the date the supplier 

received the document from the prescribing physician, and others were 

received by the supplier after the chair’s delivery. Finally, detailed 

product descriptions were not always signed and dated by the 

prescribing physician. 

Prescription. Thirty-two percent of power wheelchair claims did not 

have a complete prescription. These claims resulted in $60 million in 

improper payments by Medicare and its beneficiaries. 

Although suppliers of all but 1 percent of claims submitted the power 

wheelchair prescription, suppliers of 31 percent of claims submitted 

56 For each billed item, the supplier must include the procedure code, description, 

Medicare fee schedule amount, and supplier’s charge. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 16 
 

FINDINGS 

prescriptions that did not meet all of Medicare requirements. For 

example, 16 percent of prescriptions did not include all seven required 

elements, such as the date of the beneficiary’s examination and the 

length of time the beneficiary needed the power wheelchair. 

In addition, suppliers did not always meet the 45-day requirement. 

Specifically, suppliers of 6 percent of claims did not receive the 

prescription within 45 days after the beneficiary’s examination and, for 

another 6 percent of claims, suppliers did not receive the prescription 

before the delivery date. Other claims did not include the date the 

supplier received the prescription. For those that did, suppliers 

received the prescription within a median of 7 days after the 

beneficiary’s examination. However, the maximum amount of time was 

393 days, approximately 13 months after the examination. 

Specialty evaluation report. Beneficiaries who receive complex 

rehabilitation power wheelchairs must receive a specialty evaluation by 

a medical professional with experience in complex rehabilitation power 

wheelchair evaluations.57 Complex rehabilitation power wheelchair 

claims that were not supported by a written report of the specialty 

evaluation represented 2 percent of all standard and complex 

rehabilitation power wheelchair claims.58 However, these claims 

represented 30 percent of complex rehabilitation power wheelchair 

claims. These claims resulted in $5 million in improper payments by 

Medicare and its beneficiaries. 

Home assessment report. Eighteen percent of power wheelchair claims 

did not have a complete home assessment report. The supplier’s home 

assessment verifies that the beneficiary can adequately maneuver the 

power wheelchair in his or her home. Claims with missing or 

incomplete home assessment reports resulted in $34 million in improper 

payments by Medicare and its beneficiaries. 

Although suppliers of 10 percent of claims did not submit a home 

assessment report, suppliers of another 8 percent of claims submitted 

home assessment reports that did not meet Medicare’s requirements. 

57 The specialty evaluation requirement does not apply to standard power wheelchairs. 

58 We did not conduct a medical record review to determine whether the specialty 

evaluation report supported the medical necessity of the complex rehabilitation power 

wheelchairs and their options and accessories. OIG plans to issue a separate report on the 

appropriateness (e.g., the medical necessity) of claims for power wheelchairs and certain 

options and accessories supplied with them. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 17 
 

FINDINGS 

Specifically, suppliers of 3 percent of claims did not evaluate the 

physical layout of the beneficiary’s home in their reports. These 

suppliers usually submitted a form certifying that a home assessment 

was conducted but provided little to no information about the home’s 

dimensions, surfaces, or stairways. In addition, suppliers sometimes 

conducted the home assessment after the delivery of the chair. 

Proof of delivery. Suppliers of 1 percent of power wheelchair claims did 

not submit proof of the chair’s delivery to the beneficiary.59 

Two out of five claims had multiple documentation errors 

Thirty-eight percent of power wheelchair claims had multiple 

documentation errors. Suppliers of claims with multiple errors did not 

submit required documents and/or submitted incomplete documents. 

Incomplete documents did not have all required information or were not 

received within the required timeframe. Claims with multiple 

documentation errors accounted for $71 million in improper Medicare 

payments. 

Table 2 presents the percentage of claims and improper payments that 

Medicare allowed, by the number of documents per claim that did not 

meet Medicare requirements. 

Table 2: Number of Medicare Documentation Errors per Power 

Wheelchair Claim, First Half of 2007 

Number of Documents per 

Claim That Did Not Meet 

Medicare Requirements Claims (Percentage)* 

Payments Allowed 

(Millions) 

One 22% $41 

Two 13% $25 

Three 16% $30 

More than three 8% $16 

 Total 60% $112 

* Column does not sum because of rounding. 

Source: OIG analysis of supplier documentation, 2009. 

Suppliers submitted incomplete documents almost three times as often as 

they did not submit required documents 

Suppliers of 20 percent of standard and complex rehabilitation power 

wheelchair claims did not submit one or more documents required by 

59 We do not report improper payments by Medicare and its beneficiaries for claims that 

did not have proof of delivery because the confidence interval contained zero. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 18 
 

FINDINGS 

Medicare. Suppliers of 56 percent of claims submitted one or more 

incomplete documents. Sixteen percent of claims had both types of 

error: suppliers failed to submit at least one document and submitted 

at least one incomplete document. 

Table 3 presents the error rates for claims for which the supplier did not 

submit all required documents and those for which the supplier submitted 

an incomplete document. 

19 

Table 3: Not Submitted and Incomplete Medicare Documentation Error 

Rates for Power Wheelchair Claims, First Half of 2007 

Type of Documentation Error Error Rate 

Supplier did not submit all required documents 20% 

Supplier submitted at least one incomplete document 56% 

(Overlapping errors: supplier did not submit all required 

documents and submitted at least one incomplete document ) (16%) 

 Total 60% 

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009. 

The specialty evaluation report was one of the documents most often not 

submitted by complex rehabilitation power wheelchair suppliers. 

Beneficiaries who require complex rehabilitation power wheelchairs 

typically have mobility limitations that result from a neurological 

condition, muscle disease, or skeletal deformity; therefore, Medicare 

requires that these beneficiaries receive a specialty evaluation, in 

addition to the physician’s initial examination. However, suppliers of 

30 percent of complex rehabilitation power wheelchair claims did not 

submit a written report of the beneficiary’s specialty evaluation. The 

specialty evaluation report and detailed product description were the 

documents suppliers of complex rehabilitation power wheelchairs most 

often failed to submit.60 

60 Suppliers of 22 percent of complex rehabilitation power wheelchair claims did not 

submit a detailed product description. The differences between these error rates and other 

complex rehabilitation power wheelchair error rates are significant at the 95-percent 

confidence level. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS
 

FINDINGS 

Medicare documentation error rates varied by 

power wheelchair type and supplier volume 

during the first half of 2007 

Complex rehabilitation power 

wheelchair claims had a higher 

documentation error rate than 

standard power wheelchair claims 

during the first half of 2007. For 

standard power wheelchairs, claims submitted by low-volume suppliers 

had a higher error rate than those from high-volume suppliers. 

Complex rehabilitation power wheelchair claims had a higher 

documentation error rate than standard power wheelchair claims

Complex rehabilitation power wheelchair claims met all documentation 

requirements less frequently than standard power wheelchair claims.61 

Ninety-three percent of complex rehabilitation power wheelchair claims 

had multiple errors, while 58 percent of standard power wheelchair 

claims had multiple errors. 

Table 4 presents the error rates associated with each documentation 

requirement for standard and complex rehabilitation wheelchair claims. 

20 

Table 4: Comparison of Medicare Documentation Error Rates for Standard 

and Complex Rehabilitation Power Wheelchair Claims, First Half of 2007 

Error Rate 

Documentation Requirement 

Standard Power 

Wheelchairs 

Complex Rehabilitation 

Power Wheelchairs 

Supporting documentation 39% 61% 

Detailed product description 38% 61% 

Prescription 30% 58% 

Specialty evaluation report* NA 30% 

Home assessment report 18% 28% 

Proof of delivery 1% 1% 

(Overlapping errors) (68%) (146%) 

 Total 58% 93% 

* Requirement does not apply to standard power wheelchairs. 

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009.

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS

61 Difference is statistically significant at the 95-percent confidence level. 
 

FINDINGS 

Complex rehabilitation power wheelchair claims had higher 

documentation error rates for all requirements, except proof of 

delivery.62, 63 In the first half of 2007, suppliers submitted over 

13 times more standard than complex rehabilitation power wheelchair 

claims. The greater number of standard power wheelchair claims 

strongly influenced the combined error rates and resulted in higher 

improper payments for standard power wheelchairs than for complex 

rehabilitation power wheelchairs. Documentation errors for standard 

power wheelchairs resulted in $97 million in improper payments, while 

errors for complex rehabilitation power wheelchair claims resulted in 

$15 million in improper payments. 

Standard power wheelchair claims submitted by low-volume suppliers had a 

higher documentation error rate than those from high-volume suppliers 

Standard power wheelchair claims submitted by low-volume suppliers 

met all documentation requirements less frequently than those 

submitted by high-volume suppliers.64 Fifty-five percent of claims 

submitted by suppliers that provided 10 or more standard power 

wheelchairs in the first half of 2007 (high-volume suppliers) had 

multiple errors. Seventy-two percent of claims submitted by suppliers 

that provided fewer than 10 standard power wheelchairs (low-volume 

suppliers) had multiple errors. 

Table 5 presents the error rates associated with each documentation 

requirement for high- and low-volume suppliers. 

21 

62 Differences are statistically significant at the 95-percent confidence level. 

63 Complex rehabilitation power wheelchair claims are subject to an additional 

requirement. The specialty evaluation report requirement does not apply to standard 

power wheelchair claims. 

64 Difference is statistically significant at the 95-percent confidence level. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS
 

FINDINGS 

Table 5: Comparison of Medicare Documentation Error Rates for 

Standard Power Wheelchair Claims, by Supplier Volume, First Half of 2007 

Error Rate 

Documentation Requirement High-Volume Suppliers* Low-Volume Suppliers 

Supporting documentation 36% 51% 

Detailed product description 36% 48% 

Prescription 29% 37% 

Home assessment report 17% 18% 

Proof of delivery 1% 3% 

(Overlapping errors) (65%) (85%) 

 Total 55% 72% 

* Column does not sum because of rounding. 

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009. 

Because high-volume suppliers provide more standard power wheelchairs 

than low-volume suppliers, claims submitted by high-volume suppliers 

accounted for more improper payments for documentation errors than did 

claims submitted by low-volume suppliers.65 Documentation errors for 

standard power wheelchairs resulted in $77 million in improper payments 

for claims submitted by high-volume suppliers and $20 million for claims 

submitted by low-volume suppliers. 

22 

65 Eighty-three percent of standard power wheelchairs were supplied by high-volume 

suppliers in the first half of 2007. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS
 

 RECOMMENDATIONS 

Power wheelchairs provide mobility and independence for hundreds of 

thousands of Medicare beneficiaries. In 2005 and 2006, CMS revised 

power wheelchair documentation requirements in response to numerous 

instances of fraud and abuse and the growth in Medicare power 

wheelchair expenditures. Power wheelchair suppliers must maintain 

specific documentation to support beneficiaries’ need for the provided 

power wheelchairs. Medicare policy requires that suppliers and 

prescribing physicians coordinate to ensure that beneficiaries receive 

the most appropriate equipment to accommodate their mobility needs. 

We found that 60 percent of claims for standard and complex 

rehabilitation power wheelchairs that beneficiaries received in the first 

half of 2007 did not meet Medicare documentation requirements. These 

claims accounted for $112 million in improper Medicare payments, out 

of the $189 million total allowed by Medicare during the 6-month 

period. Beneficiaries were responsible for paying $22 million of this 

amount. 

Power wheelchair claims were more likely to meet some documentation 

requirements than others. Two out of five power wheelchair claims had 

multiple errors. In addition, suppliers submitted incomplete documents 

almost three times as often as they failed to submit required documents. 

The specialty evaluation report was one of the documents most often not 

submitted by complex rehabilitation power wheelchair suppliers. 

We found that complex rehabilitation power wheelchair claims had a 

higher documentation error rate than standard power wheelchair 

claims. Standard power wheelchair claims submitted by low-volume 

suppliers had a higher documentation error rate than those from 

high-volume suppliers. 

Based on these findings, we recommend that CMS: 

Improve compliance with Medicare’s power wheelchair 

documentation requirements 

CMS should consider the following methods for improving compliance: 

 Conduct additional reviews of power wheelchair claims. When 

determining the additional claims to review, CMS should 

consider that complex rehabilitation power wheelchair claims 

had a higher documentation error rate than standard power 

wheelchair claims. In addition, standard power wheelchair 

claims submitted by low-volume suppliers had a higher 

documentation error rate than those from high-volume suppliers. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 23 
 

RECOMMENDATIONS 

 Recover overpayments from suppliers that do not meet 

documentation requirements and consider further action as 

appropriate. Suppliers are liable for overpayments when they do 

not submit documentation to substantiate services billed to the 

program. CMS should deny claims identified during 

prepayment reviews that do not meet documentation 

requirements and recover overpayments for claims identified 

during postpayment reviews. CMS should also consider 

investigating suppliers that do not meet documentation 

requirements. 

 Increase education for suppliers and prescribing physicians about 

documentation requirements. While suppliers are ultimately 

responsible for claims they submit, Medicare requires that 

suppliers obtain documents and receive approval from the 

prescribing physicians. Therefore, CMS should consider 

physicians’ awareness of power wheelchair documentation 

requirements. 

Take appropriate action on sampled claims found to be in error

We will forward detailed information on these claims to CMS in a 

separate transmittal. 

AGENCY COMMENTS AND OFFICE OF INSPECTOR GENERAL 

RESPONSE 

CMS concurred with both of our recommendations. CMS noted that it 

has multiple efforts underway or planned that align with each 

suggested method to improve compliance with Medicare’s power 

wheelchair documentation requirements. For example, CMS recently 

awarded a contract that will involve the review of power wheelchair 

claims submitted by certain suppliers. Additionally, CMS will instruct 

DME Medicare Administrative Contractors to determine whether 

required documentation is present, in addition to determining whether 

beneficiaries are receiving medically necessary power wheelchairs. 

Further, CMS stated that it will take appropriate action to recover 

overpayments from suppliers for claims that do not meet documentation 

and policy requirements or clinical criteria. CMS also stated that it 

continues to develop educational materials for suppliers and prescribing 

providers and expects to disseminate additional information on power 

wheelchair documentation requirements to both of these groups through 

open-door forums and calls. Finally, CMS will forward the sampled 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 24 
 RECOMMENDATIONS 

claims we found to be in error to the appropriate contractors to identify 

and recover overpayments. We will forward information on these claims 

to CMS under separate cover. 

We did not make changes to the report based on CMS comments. The 

full text of CMS’s comments appears in Appendix E. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 25 
 

Medicare’s Power Wheelchair Documentation Requirements 

Document Description Requirements 

Prescription Physician’s order for a power 

wheelchair 

 Supplier must maintain on file 

 The prescription must include: 

- beneficiary name 

- beneficiary examination date 

- diagnoses and conditions that support the claim 

- item description 

- expected length of time the beneficiary will need the chair 

- prescribing physician’s signature 

- prescription date 

 45-day requirement 

- supplier must have documentation of the date the supplier received the prescription from the 

physician 

- prescription must be received by the supplier within 45 days after the beneficiary’s 

examination and before the chair’s delivery 

Supporting 

documentation 

Documentation that will 

include pertinent parts of the 

beneficiary’s medical record 

that support the medical 

necessity for the power 

wheelchair 

 Supplier must maintain on file 

 Must include beneficiary medical records, such as physician’s notes from the beneficiary’s 

examination; forms and attestations are inadequate 

 45-day requirement 

- supplier must have documentation of the date the supplier received the supporting 

documentation from the physician 

- supporting documentation must be received by the supplier within 45 days after the 

beneficiary’s examination and before the chair’s delivery 

NOT INCLUDED IN REVIEW:

 Must support the medical necessity of the power wheelchair 

 Notes from the beneficiary examination must indicate that the reason for the visit was a mobility 

examination 

Specialty 

evaluation 

report* 

Written report of the 

evaluation by physical or 

occupational therapist or 

physician justifying the need 

for the power wheelchair and 

all accessories 

 Supplier must maintain on file 

NOT INCLUDED IN REVIEW:

 Must support the medical necessity of the power wheelchair and all options and accessories 

 Specialty evaluation must be performed by a medical professional with experience in complex 

rehabilitation power wheelchair evaluations 

Detailed 

product 

description 

Document showing items that 

will be billed to Medicare 

and/or beneficiary 

 Supplier must maintain on file 

 Must include for all billed items (power wheelchair and any accessories or power options): 

- procedure code(s) of all billed items 

- item description(s) 

- Medicare fee schedule amount(s) 

- supplier charge(s) 

 Supplier must have documentation of date the supplier received the detailed product description 

from physician 

 Supplier must receive detailed product description before chair’s delivery 

 Must include prescribing physician’s signature and date of physician’s signature 

Home 

assessment 

report 

Written report documenting 

the supplier’s assessment of 

the beneficiary’s home 

environment 

 Supplier must maintain on file 

 Assessment must have occurred before or during the chair’s delivery 

 Assessment must address the physical layout of the home 

Proof of 

delivery 

Documentation showing the 

power wheelchair was 

delivered to the beneficiary 

 Supplier must maintain on file 

* Applies only to complex rehabilitation power wheelchairs. 

Source: Medicare Power Mobility Device Local Coverage Determination. 

 APPENDIX~A 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 26 
 

Population and Sample Sizes by Stratum, First Half of 2007 

Population Sample 

 Stratum Definition Claims Expenditures Suppliers Claims Expenditures Suppliers 

1 

Standard power wheelchair claims 

by low-volume suppliers 7,223 $28,949,132 2,352 125 $499,152 124 

2 

Standard power wheelchair claims 

by high-volume suppliers 35,910 $144,354,060 716 125 $502,989 94 

1 and 2 

All standard power wheelchair 

claims 43,133 $173,303,192 3,068 250 $1,002,141 218 

3 

Complex rehabilitation power 

wheelchair claims* 3,001 $16,010,906 1,064 125 $665,200 113 

 Total 46,134 $189,314,098 3,362** 375 $1,667,341 325** 

* Procedure codes K0835–K0864. 

** Suppliers’ figures do not sum to totals because of overlap (some suppliers in our sample provided both standard and complex rehabilitation power wheelchairs). 

Source: Office of Inspector General analysis of Medicare power wheelchair claims with dates of service from January 1 to June 30, 2007. 

 APPENDIX~B 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 27 
 

28 

Incomplete Documentation Error Rates, First Half of 2007 

Document Incomplete Documentation Error Description Error Rate

Did not include physician’s notes from medical record 20.4% 

No documentation of date supplier received supporting documentation 9.9% 

Included documentation of the date the supplier received the supporting 

documentation, but the supplier did not receive the supporting documentation 

within 45 days after the beneficiary examination 9.1% 

Included documentation of the date the supplier received the supporting 

documentation, but the supplier did not receive the supporting documentation 

before the delivery date 8.1% 

Overlapping errors (9.2%) 

Supporting 

documentation 

 Total incomplete documentation 38.3% 

Did not include all required information for all billed items 17.1% 

No physician signature 0.4% 

No date of physician signature 0.8% 

No documentation of the date the supplier received the detailed product 

description from the physician 8.4% 

Included documentation of the date the supplier received the detailed product 

description, but the supplier did not receive the detailed product description 

before the delivery date 5.4% 

Overlapping errors (6.0%) 

Detailed product 

description 

 Total incomplete documentation 26.1% 

One or more required elements missing 15.9% 

No documentation of the date the supplier received the prescription 9.1% 

Included documentation of the date the supplier received the prescription, but 

the supplier did not receive the prescription within 45 days after the beneficiary 

examination 5.5% 

Included documentation of the date the supplier received the prescription, but 

the supplier did not receive the prescription before the delivery date 5.9% 

Overlapping errors (5.6%) 

Prescription 

 Total incomplete documentation 30.8% 

Home assessment was conducted after chair’s delivery 6.9% 

Home assessment report did not address the physical layout of the 

beneficiary’s home 2.5% 

Overlapping errors (1.0%) 

Home assessment 

report 

 Total incomplete documentation 8.4% 

Note: Overlapping errors are subtracted to obtain the total. 

Source: Office of Inspector General analysis of supplier documentation, 2009.

 APPENDIX~C 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS
 

APPENDIX C 

APPENDIX D 

29 

Estimates and Confidence Intervals: Medicare Documentation Error Rates for Standard and 

Complex Rehabilitation Power Wheelchair Claims, First Half of 2007

Estimate Description Sample Size Point Estimate

95-Percent Confidence 

Interval 

All Power Wheelchairs 

Supporting documentation 365 40.3% 33.6%–47.3% 

Detailed product description 365 39.7% 33.1%–46.7% 

Prescription 365 32.1% 26.0%–38.9% 

Specialty evaluation report** 365 2.0% 1.5%–2.6% 

Home assessment report 365 18.2% 13.4%–24.3% 

Proof of delivery 365 1.2% 0.4%–3.7% 

Overlapping errors 365 (73.1%) (58.8%–87.4%) 

 Total errors 365 60.4% 53.2%–67.2% 

Standard Power Wheelchairs: All Suppliers 

Supporting documentation 241 38.8% 31.7%–46.3% 

Detailed product description 241 38.2% 31.2%–45.8% 

Prescription 241 30.2% 23.8%–37.6% 

Home assessment report 241 17.5% 12.5%–24.1% 

Proof of delivery 241 1.2% 0.4%–4.0% 

Overlapping errors 241 (67.8%) (52.6%–83.2%) 

 Total errors 241 58.1% 50.4%–65.4% 

Complex Rehabilitation Power Wheelchairs 

Supporting documentation 124 61.3% 52.5%–69.4% 

Detailed product description 124 60.5% 51.7%–68.6% 

Prescription 124 58.1% 49.3%–66.4% 

Specialty evaluation report** 124 29.8% 22.5%–38.4% 

Home assessment report 124 28.2% 21.1%–36.7% 

Proof of delivery 124 0.8% 0.1%–5.4% 

Overlapping errors 124 (146.0%) (124.2%–167.8%) 

 Total errors 124 92.7% 86.7%–96.2% 

** Requirement does not apply to standard power wheelchairs. 

Note: Overlapping errors are subtracted to obtain the total. 

Source: Office of Inspector General (OIG) analysis of supplier documentation, 2009.

 APPENDIX~D 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS
 

APPENDIX D 

Estimates and Confidence Intervals: Medicare Documentation Error Rates for Low- and 

High-Volume Standard Power Wheelchair Claims, First Half of 2007

Estimate Description Sample Size Point Estimate

95-Percent Confidence 

Interval 

Standard Power Wheelchairs: Low-Volume Suppliers 

Supporting documentation 120 50.8% 41.9%–59.7% 

Detailed product description 120 47.5% 38.7%–56.5% 

Prescription 120 36.7% 28.5%–45.7% 

Home assessment report 120 18.3% 12.4%–26.3% 

Proof of delivery 120 3.3% 1.2%–8.6% 

Overlapping errors 120 (85.0%) (64.3%–105.7%) 

 Total errors 120 71.7% 62.9%–79.0% 

Standard Power Wheelchairs: High-Volume Suppliers 

Supporting documentation 121 36.4% 28.2%–45.4% 

Detailed product description 121 36.4% 28.2%–45.4% 

Prescription 121 28.9% 21.5%–37.7% 

Home assessment report 121 17.4% 11.5%–25.3% 

Proof of delivery 121 0.8% 0.1%–5.8% 

Overlapping errors 121 (64.5%) (46.5%–82.4%) 

 Total errors 121 55.4% 46.3%–64.1% 

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009.

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 30 
 

APPENDIX D 

Estimates and Confidence Intervals: Improper Payments for Power Wheelchair Claims With 

Documentation Errors, First Half of 2007

Estimate Description Sample Size Point Estimate 95-Percent Confidence Interval 

All Power Wheelchairs 

Supporting documentation 365 $74,702,894 $62,297,706–$87,108,083 

Detailed product description 365 $73,530,908 $61,136,655–$85,925,162 

Prescription 365 $59,769,646 $48,047,256–$71,492,036 

Specialty evaluation report** 365 $4,695,238 $3,422,965–$5,967,511 

Home assessment report 365 $33,971,678 $24,166,707–$43,776,648 

Overlapping improper payments 365 ($136,894,371) ($110,972,878–$162,815,864) 

Total improper payments* 365 $111,962,318 $99,272,522–$124,652,115 

Beneficiary’s copayment 365 $21,742,270 $19,194,534–$24,290,011 

Complex Rehabilitation Power Wheelchairs 

Total improper payments 124 $14,704,007 $13,883,853–$15,524,161 

Standard Power Wheelchairs: All Suppliers 

Total improper payments 241 $97,258,311 $84,572,801–$109,943,821 

Standard Power Wheelchairs: Low-Volume Suppliers 

Total improper payments 120 $19,803,457 $17,550,837–$22,056,078 

Standard Power Wheelchairs: High-Volume Suppliers 

Total improper payments 121 $77,454,854 $64,905,544–$90,004,163 

* We do not report improper payments by Medicare and its beneficiaries for claims that did not have proof of delivery because the confidence 

intervals contain zero. Therefore, improper payments do not add to the total. 

** Requirement does not apply to standard power wheelchairs. 

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 31 
 

APPENDIX D 

Estimates and Confidence Intervals: Number of Medicare Documentation Errors per Power Wheelchair 

Claim, First Half of 2007 

Estimate Description 

Sample 

Size 

Point 

Estimate 

95-Percent Confidence 

Interval 

Percentage of claims that met all Medicare documentation requirements 365 39.6% 32.8%–46.8% 

Percentage of claims with one document that did not meet all Medicare 

documentation requirements 365 22.2% 16.9%–28.5% 

Percentage of claims with two documents that did not meet all Medicare 

documentation requirements 365 13.4% 9.3%–18.8% 

Percentage of claims with three documents that did not meet all Medicare 

documentation requirements 365 16.4% 11.8%–22.3% 

Percentage of claims with more than three documents that did not meet 

all Medicare documentation requirements 365 8.5% 5.5%–12.9% 

Percentage of claims with multiple Medicare documentation errors 365 38.2% 31.7%–45.2% 

Improper payments for claims with one document that did not meet all 

Medicare documentation requirements 365 $40,682,641 $30,244,946–$51,120,336 

Improper payments for claims with two documents that did not meet all 

Medicare documentation requirements 365 $24,873,263 $16,351,987–$33,394,540 

Improper payments for claims with three documents that did not meet all 

Medicare documentation requirements 365 $30,048,940 $20,676,710–$39,421,170 

Improper payments for claims with more than three documents that did 

not meet all Medicare documentation requirements 365 $16,357,474 $9,760,665–$22,954,282 

Improper payments for claims with multiple Medicare documentation 

errors 365 $71,279,677 $59,005,460–$83,553,895 

Source: OIG analysis of supplier documentation, 2009. 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 32 
 

APPENDIX D 

Estimates and Confidence Intervals: Not Submitted and Incomplete Medicare Documentation 

Error Rates for Power Wheelchair Claims, First Half of 2007 

Estimate Description Sample Size Point Estimate

95-Percent 

Confidence Interval 

Supporting Documentation 

Document not submitted 365 2.0 % 0.8%–5.0% 

Incomplete documentation 365 38.3% 31.7%–45.3% 

 Total errors 365 40.3% 33.6%–47.3% 

Detailed Product Description 

Document not submitted 365 13.6% 9.7%–18.7% 

Incomplete documentation 365 26.1% 20.4%–32.8% 

 Total errors 365 39.7% 33.1%–46.7% 

Prescription 

Document not submitted 365 1.3% 0.8%–2.2% 

Incomplete documentation 365 30.8% 24.7%–37.6% 

 Total errors 365 32.1% 26.0%–38.9% 

Home Assessment Report 

Document not submitted 365 9.9% 6.4%–14.8% 

Incomplete documentation 365 8.4% 5.2%–13.2% 

 Total errors 365 18.2% 13.4%–24.3% 

Specialty Evaluation Report 

Complex rehabilitation power wheelchair claims for 

which the supplier did not submit a specialty evaluation 

report 124 29.8% 22.5%–38.4% 

All power wheelchair claims for which the supplier did 

not submit a specialty evaluation report 365 2.0% 1.5%–2.6% 

Proof of Delivery 

Document not submitted 365 1.2% 0.4%–3.7% 

All Documents 

At least one document not submitted 365 19.9% 15.1%–25.6% 

At least one document incomplete 365 56.5% 49.3%–63.4% 

Overlapping errors 365 (15.9%) (11.1%–20.7%) 

 Total errors 365 60.4% 53.2%–67.2% 

Ratio of claims with incomplete document(s) to claims 

with document(s) not submitted 365 2.84 2.09–3.60 

Source: OIG analysis of supplier documentation, 2009.

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 33 
 

APPENDIX D 

Estimates and Confidence Intervals: Comparisons of Medicare Documentation Error Rates by Wheelchair 

Type and Supplier Volume, First Half of 2007

Estimate Description 

Sample 

Size 

Point 

Estimate 

95-Percent 

Confidence 

Interval P-Value 

Comparisons by Wheelchair Type 

Difference in percentage of power wheelchairs for which the supplier did 

not submit complete supporting documentation 365 22.5% 11.3%–33.7% 0.0001 

Difference in percentage of power wheelchairs for which the supplier did 

not submit a complete detailed product description 365 22.3% 11.0%–33.5% 0.0001 

Difference in percentage of power wheelchairs for which the supplier did 

not submit a complete prescription 365 27.9% 16.8%–38.9% <0.0001 

Difference in percentage of power wheelchairs for which the supplier did 

not submit a complete home assessment report 365 10.7% 1.0%–20.4% 0.0309 

Difference in percentage of power wheelchairs for which the supplier did 

not submit one or more complete documents 365 34.7% 25.9%–43.4% <0.0001 

Comparisons by Supplier Volume 

Difference in percentage of standard power wheelchairs for which the 

supplier did not submit complete supporting documentation 241 14.5% 2.0%–26.9% 0.0228 

Difference in percentage of standard power wheelchairs for which the 

supplier did not submit one or more complete documents 241 16.3% 4.3%–28.3% 0.0082 

Source: OIG analysis of supplier documentation, 2009.

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 34 
 

APPENDIX D 

Estimates and Confidence Intervals: Incomplete Medicare Documentation Error Rates, First Half of 2007 

Estimate Description 

Sample 

Size 

Point 

Estimate 

95-Percent 

Confidence Interval 

Supporting Documentation 

Did not include physician’s notes from medical record 365 20.4% 15.6%–26.1% 

No documentation of date supplier received supporting documentation 365 9.9% 6.5%–14.9% 

Included documentation of the date the supplier received the supporting 

documentation, but the supplier did not receive the supporting documentation within 

45 days after the beneficiary examination 365 9.1% 5.8%–13.9% 

Included documentation of the date the supplier received the supporting 

documentation, but the supplier did not receive the supporting documentation before 

the delivery date 365 8.1% 4.9%–13.2% 

Overlapping errors 365 (9.2%) (5.0%–13.4%) 

 Total incomplete documentation 365 38.3% 31.7%–45.3% 

Median number of days for supplier receipt of supporting documentation after 

beneficiary examination 365 6.8 5.0–10.9 

Detailed Product Description 

Did not include all required information for all billed items 365 17.1% 12.5%–22.9% 

No physician signature 365 0.4% 0.2%–1.2% 

No date of physician signature 365 0.8% 0.4%–1.6% 

No documentation of the date the supplier received the detailed product description 

from the physician 365 8.4% 5.2%–13.3% 

Claim included documentation of the date the supplier received the detailed product 

description but the supplier did not receive the detailed product description before the 

delivery date 365 5.4% 2.9%–9.8% 

Overlapping errors 365 (6.0%) (2.9%–9.1%) 

 Total incomplete documentation 365 26.1% 20.4%–32.8% 

Prescription 

One or more required elements missing 365 15.9% 11.6%–21.4% 

No documentation of the date the supplier received prescription 365 9.1% 5.7%–14.1% 

Included documentation of the date the supplier received the prescription, but the 

supplier did not receive the prescription within 45 days after the beneficiary 

examination 365 5.5% 3.1%–9.5% 

Included documentation of the date the supplier received the prescription, but the 

supplier did not receive the prescription before the delivery date 365 5.9% 3.3%–10.3% 

Overlapping errors 365 (5.6%) (2.6%–8.5%) 

 Total incomplete documentation 365 30.8% 24.7%–37.6% 

Median number of days for supplier receipt of prescription after beneficiary examination 365 6.6 4.6–12.0 

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009.

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 35 
 

APPENDIX D 

Estimates and Confidence Intervals: Incomplete Medicare Documentation Error Rates, First Half of 2007 

(continued) 

Estimate Description 

Sample 

Size 

Point 

Estimate 

95-Percent 

Confidence Interval 

Home Assessment Report 

Home assessment was conducted after chair’s delivery 365 6.9% 4.0%–11.7% 

Home assessment report did not address the physical layout of the beneficiary’s home 365 2.5% 1.2%–5.2% 

Overlapping errors 365 (1.0%) (0.0%–2.3%)

 Total incomplete documentation 365 8.4% 5.2%–13.2%

Note: Overlapping errors are subtracted to obtain the total. 

Source: OIG analysis of supplier documentation, 2009.

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 36 
A P PEN 0 x E 


.. ,,,,..,,~ l4 DEPARTMENT OF HEALTH & HUMAN SERVICES Centers for Medicare & Medicaid Services 

Administrator 

Washington, DC 20201 

DATE: NOV 1 9 2009 

TO: Daniel R. Levinson 

Inspector General 

FROM: -Charlene Frizzera 

Acting Administrator 

SUBJECT: Office ofInspector General (OIG) Draft Report: "Medicare Power Wheelchair 

Claims Frequently Did Not Meet Documentation Requirements" . 

(OEI-04-07-00401) 

Thank you for the opportunity to review and comment on the OIG's draft report, "Medicare 

Power Wheelchair Claims Frequently Did Not Meet Documentation Requirements." The 

Centers for Medicare & Medicaid Services (CMS) appreciates the time and resources the OIG 

has invested to determine the extent to which standard and complex rehabilitation power 

wheelchair claims met Medicare documentation requirements. 

The CMS requires suppliers to maintain specific documentation that supports the beneficiary's 

need for a power mobility device. The OIG found that 60 percent of claims for standard and 

complex rehabilitation power wheelchairs did not meet all Medicare documentation 

requirements. These claims accounted for $112 million in improper payments. The OIG also 

found complex rehabilitation wheelchairs had a higher documentation error rate than standard 

power wheelchair claims. 

The CMS recognizes the complexity of power wheelchair claims and is committed to continually 

reviewing and refining its processes to reduce improper payments. We are also committed to 

ensuring that Medicare contractors follow and apply our policies and documentation 

requirements while reviewing claims. 

The OIG made the following recommendations. 

OIG Recommendation 

Improve compliance with Medicare'~ power wheelchair documentation requirements. 

Conduct additional reviews ofpower wheelchair claims. 

OEI·04·07·00401 MEDICARE POWER WHEELCHAIR CLAIMS FREQUENTLY DID NOT MEET DOCUMENTATION REQUIREMENTS 37 
 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 38 

APPENDIX E 
 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 39 

APPENDIX E 
 

APPENDIX E 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 40 
 

APPENDIX E 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 41 
 

OEI-04-07-00401 MEDICARE P OWER WHEELCHAIR CLAIMS F REQUENTLY DID N OT MEET D OCUMENTATION REQUIREMENTS 42 

 ACKNOWLEDGMENTS 

This report was prepared under the direction of Dwayne F. Grant, 

Regional Inspector General for Evaluation and Inspections in the 

Atlanta regional office. 

Sarah Ambrose and Mina Zadeh served as team leaders for this study. 

Other principal Office of Evaluation and Inspections staff from the 

Atlanta regional office who contributed to this report include Peggy 

Daniel. Berivan Demir, Kevin Farber, and Scott Manley from the 

central office; Carolyn Kenline from the Boston regional office; and 

Robert A. Vito from the Philadelphia office also contributed.