(:~ 	
DEPARTMENT OF HEALTH & HUMt.N SERVICES  Office of Inspector General 
Washington, DC 	 20201 
JAN 092012 
TO: 	 Marilyn Tavenner 

Acting Administrator 

Centers for Medicare & Medicaid Services 

FROM:  Stuart Wright 

Deputy Inspector General 

for Evaluation and Inspections 

SUBJECT: 	 Memorandum Report:  Comparison ofAverage Sales Prices to Widely 
Available Market Prices for Selected Drugs, OEI-03-10-00280 
This review was conducted in accordance with the statutory mandate for the Office of 
Inspector General (OIG) to compare average sales prices (ASP) to widely available 
market prices (WAMP) for Medicare Part B prescription drugs and to identify ASPs that 
exceed W AMPs by at least 5 percent. 
SUMMARY 
Federal law requires OIG to conduct studies that compare ASPs to WA  MPs and average 
manufacturer prices (AMP).  If OrG finds that the ASP of a drug exceeds either the 
WAMP or AMP by a certain threshold (currently 5 percent), the Secretary of Health and 
Human Services (the Secretary) may disregard the ASP for the drug when setting 
reimbursement amounts.  Since the implementation ofthe ASP reimbursement 
methodology, OIG has issued 27 reports comparing ASPs to W AMPs and AMPs 
(2 comparing ASPs to WAMPs, 25 comparing ASPs to AMPs). 
The purpose of this review was to compare ASPs to W AMPs for 14 drugs that have been 
identified in previous OIG reports as repeatedly exceeding the 5-percent ASP-AMP 
threshold.  However, limitations and irregularities in the sales data provided by the 
distributors and manufacturers ofthe 14 drugs called into question the data's accuracy 
and reliability, and prevented us from measuring WA  MPs against the threshold. 
 	 All of the manufacturers that reported direct sales to providers included data on 
their discounts and rebates for those sales.  However, two distributors (which sold 
over half ofall the units reported to us) were not able to determine the discounts 
and rebates they provided, meaning that the WA  MPs we calculated most likely 
did not reflect the actual prices paid in the marketplace.  In the past, OIG has had  Page 2  Marilyn Tavenner 
 
 
difficulty obtaining data on discounts and rebates from distributors, but in those 
instances, the missing data did not have the same impact on our results. 
 
  Furthermore, the total number of units sold reported to us by distributors and 
manufacturers differed substantially from the number reported to the Centers for 
Medicare & Medicaid Services (CMS) through quarterly ASP submissions, 
potentially resulting in our data reflecting an inaccurate number of sales. 
 
  Most likely because of these issues, the WAMPs we calculated varied widely 
from other pricing points; several drugs had WAMPs that were substantially 
higher than the associated ASPs and AMPs. 
 
We plan to continue to fulfill our statutory mandate to conduct WAMP studies, and these 
issues will need to be addressed before any future efforts can be made to compare ASPs 
to WAMPs.  We will consider alternative methodologies that will allow us to conduct 
pricing comparisons, including directly surveying providers to obtain accurate and 
complete sales data. 
 
BACKGROUND 
 
Medicare Part B Coverage of Prescription Drugs 
Although Medicare Part D covers most outpatient prescription drugs, CMS continues to 
cover a limited number of outpatient prescription drugs and biologicals (hereinafter 
referred to as drugs) under its Part B benefit.  Covered drugs include injectable drugs 
administered by a physician; certain self-administered drugs, such as oral anticancer 
drugs and immunosuppressive drugs; drugs used in conjunction with durable medical 
equipment; and some vaccines.  Part B and its beneficiaries spent $12 billion for more 
than 600 outpatient prescription drugs in 2010. 
 
Medicare Part B Payment for Prescription Drugs 
To obtain Medicare payment for Part B-covered drugs, physicians and suppliers submit 
claims using the Healthcare Common Procedure Coding System (HCPCS) codes.  In the 
case of prescription drugs, each HCPCS code defines the drug ingredient name and 
billing unit size but does not specify the manufacturer or package size. 
 
Part B pays for most covered drugs using a methodology based on ASPs.  Manufacturers 
report ASPs for their covered drugs to CMS on a quarterly basis.  The ASP is defined as 
a manufacturers sales of a drug to all purchasers in the United States in a calendar 
quarter (net of most discounts) divided by the total number of units of the drug sold by  
 
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the manufacturer in that same quarter.1  This includes sales to distributors and 
wholesalers (distributors) and direct sales to providers.  Manufacturers report ASPs for 
Part B-covered drugs by national drug codes (NDC), which are 11-digit numeric codes 
divided into three segments identifying (1) the firm that manufactures, distributes, or 
repackages the drug product (i.e., the labeler code); (2) the specific strength, dosage form, 
and formulation of the product; and (3) the products package size.2 
 
Because Part B reimbursement for outpatient drugs is based on HCPCS codes rather than 
NDCs and more than one NDC may meet the definition of a particular HCPCS code, 
CMS has developed a file (the ASP background file3) that crosswalks manufacturers 
NDCs to HCPCS codes.  CMS uses information in this file to calculate volume-weighted 
ASPs for covered HCPCS codes based on the data from the relevant NDCs.  The 
Medicare payment amount for most Part B drugs is equal to 106 percent of the  
volume-weighted ASP for the HCPCS code.  Medicare beneficiaries are generally 
responsible for 20 percent of this amount in the form of coinsurance. 
 
OIGs Monitoring of ASPs, AMPs, and WAMPs 
Federal law requires OIG to conduct studies that compare ASPs to WAMPs and  
AMPs.4, 5  If OIG finds that the ASP of a drug exceeds either the WAMP or AMP by a 
certain threshold (currently 5 percent), the Act states that the Secretary may disregard the 
ASP for the drug when setting reimbursement amounts,6, 7 and that ... the Inspector 
General shall inform the Secretary (at such times as the Secretary may specify to carry 
out this subparagraph) and the Secretary shall, effective as of the next quarter, substitute 
                                                 
1 Section 1847A(c) of the Social Security Act (the Act), as added by the Medicare Prescription Drug, 
Improvement, and Modernization Act of 2003, P.L. 108-173.  Pursuant to  1847A(c) of the Act, ASP is 
net of any price concessions, such as volume discounts, prompt-pay discounts, cash discounts, free goods 
contingent on purchase requirements, chargebacks, and rebates other than those obtained through the 
Medicaid drug rebate program.  Sales that are nominal in amount are exempted from the ASP calculation, 
as are sales excluded from the determination of best price in the Medicaid drug rebate program. 
2 Pursuant to  1927(a)(1) and (b)(1) of the Act, for Federal payment to be available for covered outpatient 
drugs provided under Medicaid, drug manufacturers must enter into rebate agreements with the Secretary.  
Manufacturers with Medicaid drug rebate agreements in effect must, among other things, provide CMS 
with pricing information, including the ASP for each of their Part B-covered drugs and the AMP for each 
of their applicable Medicaid-covered drugs. 
3 CMS provides OIG with the ASP background file each quarter.  This file contains ASP data (including 
the ASP itself and the number of units sold in the quarter) for all NDCs (grouped by their corresponding 
HCPCS codes) that were reported in that quarter. 
4 Section 1847A(d)(2) of the Act. 
5 Section 1927(k)(1) of the Act, as amended by section 2503(a)(2) of the Affordable Care Act,  
P.L. 111-148, defines AMP as the average price paid to the manufacturer for the drug in the United States 
by wholesalers for drugs distributed to retail community pharmacies and by retail community pharmacies 
that purchase drugs directly from the manufacturer, with certain exclusions. 
6 Section 1847A(d)(3)(A) of the Act. 
7 Section 1847A(d)(3)(B)(ii) of the Act provided the Secretary with authority to adjust the applicable 
threshold percentage in 2006 and subsequent years; however, the threshold percentage has been maintained 
at 5 percent. 
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for the amount of payment ... the lesser of (i) the widely available market price ... (if 
any); or (ii) 103 percent of the average manufacturer price....8  The Act defines WAMP 
as the price that a prudent physician or supplier would pay for the drug, and states that 
[i]n determining such price, the Inspector General shall take into account the discounts, 
rebates, and other price concessions routinely made available to such prudent physicians 
or suppliers for such drugs or biologicals.9  
 
Since 2006, OIG has issued 27 reports (2 comparing ASPs to WAMPs, 25 comparing 
ASPs to AMPs), and has repeatedly identified certain drugs with ASPs that exceeded the 
5-percent threshold in one or more quarters.  For example, a 2010 OIG report comparing 
ASPs to AMPs found that 26 drugs exceeded the 5-percent threshold in the third quarter 
of 2009.10  Lowering reimbursement amounts for the 26 drugs to 103 percent of the AMP 
would have reduced Medicare expenditures by $2.7 million in the first quarter of 2010.  
Fourteen of the drugs that exceeded the 5-percent threshold in the third quarter of 2009 
also exceeded the threshold in at least one of the previous four quarters. 
 
Although CMS has yet to make changes to Part B reimbursement as a result of OIGs 
pricing comparisons, in November 2011 CMS issued a Notice of Final Rulemaking that 
applies price substitutions beginning in 2012 to certain drugs that repeatedly exceed the 
5-percent AMP threshold.11  CMS stated that it is excluding WAMP from the price 
substitutions because of the lack of data regarding comparisons between ASPs and 
WAMPs; however, the agency will reconsider proposing a policy for price substitutions 
based on ASP and WAMP comparisons at a later date.12  Furthermore, in its comments 
on another OIG pricing comparison, CMS also stated that additional analysis of pricing 
data is an important next step in developing a price substitution policy.13  This current 
study, which focused on drugs that have repeatedly exceeded the 5-percent AMP 
threshold, was intended to provide further analysis to assist CMS in its efforts to develop 
a price substitution policy. 
 
 
 
 
 
 
                                                 
8 Section 1847A(d)(3)(C)  of the Act. 

9 Section 1847A(d)(5)(A)  of the Act. 

10 OIG,  Comparison of Third-Quarter 2009 Average Sales Prices and Average Manufacturer Prices: 
 
Impact on Medicare Reimbursement for First Quarter 2010 (OEI-03-10-00150), April 2010. 

11 76 Fed. Reg. 73026, 73293  (Nov. 28, 2011).  Specifically, CMS will substitute prices for drugs that 

exceed the 5-percent AMP threshold in two consecutive quarters, or three of four quarters.  Price 

substitutions will only apply to  drugs with complete AMP data, and will remain in effect for one quarter. 

12 Ibid., at 73287. 

13 OIG,  Comparison of Average Sales Prices and Average Manufacturer Prices:  An  Overview of 2008  
 
(OEI-03-09-00350), February 2010. 

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METHODOLOGY 
 
In an April 2010 report comparing ASPs and AMPs, we identified 14 HCPCS codes that 
exceeded the 5-percent threshold in the third quarter of 2009 and at least one of the 
previous four quarters (see Table 1).  Eight of the 14 drugs exceeded the threshold based 
on complete AMP data, and 6 exceeded the threshold based on partial AMP data.14 
 
Table 1:  Fourteen HCPCS Codes That Exceeded the 5-Percent  
ASP-AMP Threshold in the Third Quarter of 2009 and at Least One 
of the Four Previous Quarters 
HCPCS Code  Drug Name 
J0560*  Penicillin g benzathine inj., 600,000 units 
J1190  Dexrazoxane HCl inj., 250 mg 
J1364  Erythro lactobionate, 500 mg 
J2597  Desmopressin acetate inj., 1 mcg 
J2765  Metoclopramide HCl inj., 10 mg 
J2792*  Rho(D) immune globulin h, sd, 100 units 
J2993*  Reteplase inj., 18.1 mg 
J3470*  Hyaluronidase inj., 150 units 
J7506  Prednisone oral, 5 mg 
J7509  Methylprednisolone oral, 4 mg 
J9340  Thiotepa inj., 15 mg 
Q0163  Diphenhydramine HCl, 50 mg 
Q9965*  Low osmolar contrast material, 100199 mg/mL iodine, 1 mL 
Q9966*  Low osmolar contrast material, 200299 mg/mL iodine, 1 mL 
mg=milligram, mcg=microgram, and mL=milliliter 
Source:  OIG, Comparison of Third-Quarter 2009 Average Sales Prices and Average Manufacturer Prices:  Impact on 
Medicare Reimbursement for First Quarter 2010 (OEI-03-10-00150), April 2010. 
* Indicates the drug is only available in brand-name form. 
 
We surveyed each of the 23 manufacturers with NDCs in CMSs ASP background file 
that were associated with any of the 14 HCPCS codes listed in Table 1.  We asked each 
manufacturer to provide pricing data for any direct purchases by suppliers or physicians 
in third-quarter 2009, fourth-quarter 2009, and first-quarter 2010.  Because WAMP is 
defined as being net of any discounts and rebates,15 we asked the manufacturers to 
provide data on discounts and rebates.  Because many providers purchase drugs from 
distributors rather than directly from manufacturers, the manufacturer-reported sales data 
alone would not reflect all sales to providers.  Therefore, we also asked each 
                                                 
14 A HCPCS code with complete AMP data is one with AMP data for every NDC that CMS used in its 
calculation of the HCPCS codes volume-weighted ASP. 
15 Section 1847A(d)(5)(A) of the Act. 
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manufacturer to provide the contact information for all distributors to which it sold any of 
the drugs during the quarters under review.  The 23 manufacturers reported selling these 
drugs to 127 distributors.  We then surveyed all 127 distributors, and asked for data on 
their sales to providers for any NDCs that met the description of any of the 14 drugs in 
third-quarter 2009, fourth-quarter 2009, and first-quarter 2010.  We asked the distributors 
to break down the data by class of trade, and to provide data on discounts and rebates. 
 
We received responses from every manufacturer and distributor.16  We compiled the 
sales data reported by the 23 manufacturers and 127 distributors for each drug in each of 
the three quarters.  We excluded data on sales made to institutional classes of trade and 
on sales of NDCs not included in CMSs calculation of ASPs.  We calculated the  
volume-weighted WAMP for each of the 14 HCPCS codes in each of the three quarters 
by using the NDC-level pricing data provided by the distributors and direct sales data 
provided by the manufacturers.  When available, we included all discounts and rebates.  
We then obtained volume-weighted ASPs for each of the three quarters from CMS, and 
compared these figures to the volume-weighted WAMP in each quarter. 
 
Limitations 
We did not verify the accuracy or completeness of CMSs ASP data or the sales data 
provided to us by the manufacturers and distributors. 
 
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. 
 
RESULTS 
  
Limitations and irregularities in the sales data prevented an accurate determination 
of whether any of the 14 drugs exceeded the ASP-WAMP threshold 
 
Because of limitations in the distributor-reported data, most of the sales data we received 
did not reflect discounts and rebates that were passed on to providers.  Because WAMP is 
statutorily defined as being net of any routinely available price concessions, we asked the 
manufacturers and distributors to include data on discounts and rebates along with their 
sales data.  All of the manufacturers that reported direct sales included data on their 
discounts and rebates.  However, two large distributors reported that they calculate 
discounts and rebates based on each customers total purchases for a variety of drugs, 
rather than individual sales transactions for each drug, and therefore they were unable to 
determine the amount of discounts and rebates provided for each NDC.  In other words, 
although these distributors responded to our request and provided their total sales data, 
they could not calculate the net price for each drug. 
                                                 
16 In some cases, respondents reported that they had no sales of the drugs to providers in the quarters under 
review. 
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These two distributors accounted for 58 percent of all units sold during the three quarters 
under review, meaning that more than half of the sales data we received for each quarter 
did not include any information on the discounts and rebates received by providers.  For 
example, for the third quarter of 2009, we were provided data on discounts and rebates 
for only 42 percent of all units sold.17  Among the individual drugs, the proportion of 
sales data that included discounts and rebates in that quarter ranged from 4 to 51 percent. 
 
Because of the incomplete data on discounts and rebates, the WAMPs we calculated most 
likely did not reflect the actual prices paid in the marketplace, and therefore could not 
appropriately be compared to the 5-percent threshold.  In addition, because the price 
concessions offered by these two large distributors may have differed substantially from 
the average price concessions, it is not possible to estimate discounts and rebates for 
these sales. 
 
The total number of units sold reported to us through the WAMP survey differed 
substantially from those reported to CMS through manufacturers ASP submissions, with 
the possible implication that our data represented an inaccurate number of sales.  Because 
manufacturers are required to report all sales of a drug when submitting quarterly ASP 
data to CMS, and our survey requested all direct sales data from every manufacturer and 
distributor of each drug, the total units sold reported to CMS would be expected to 
resemble those reported through our survey.  However, for 11 of the 14 drugs, ASP units 
reported to CMS differed by more than 10 percent from the WAMP units reported to us 
for third-quarter 2009.18, 19  ASP units were greater than WAMP units for eight drugs, 
and WAMP units were greater than ASP units for six drugs.  In three cases, 
manufacturers reported over twice as many units sold in CMSs ASP background file 
than were reported to us.  See Table 2 for a comparison of the total units reported to CMS 
through ASP submissions and the total units submitted in response to our WAMP survey. 
 
 
 
 
 
 
                                                 
17 We were provided discount and rebate data for 40 percent of units sold in fourth-quarter 2009 and  
44 percent of units sold in first-quarter 2010. 
18 For the purposes of this analysis, we included only units reported to us through the WAMP survey for 
NDCs used in CMSs calculation of ASPs.  These included units sold to institutional classes of trade. 
19 These figures were similar in the remaining two quarters:  12 of the 14 drugs had units that differed by 
more than 10 percent in fourth-quarter 2009, and 11 of 13 drugs had units that differed by more than  
10 percent in first-quarter 2010.  One drug in this quarter had no sales reported to us or sales reported in 
CMSs ASP background file. 
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Table 2:  Units Reported to CMS and OIG, Third-Quarter 2009 
 
  HCPCS Code1  Units Reported to CMS  Units Reported to OIG  PDeifrfceernentacgee2  
 
1  14,387,315  6,582,136  118.58% 
 
2  38,581,894  17,891,338  115.65% 
 
  3  15,737,251  7,133,905  120.60% 
  4  7,442  12,140  -38.70% 
 
5  1,117,331  1,174,360  -4.86% 
 
6  70,780  94,284  -24.93% 
 
7  2,062,877  1,579,540  30.60% 
 
  8  30,286  29,370  3.12% 
  9  6,425,800  6,350,280  1.19% 
  10  502,080  600,655  -16.41% 
 
11  65,170  56,093  16.18% 
 
12  3,014  5,314  -43.28% 
 
13  13,476  17,977  -25.04% 
 
  14  82,037,410  55,509,110  47.79% 
  Total  161,042,126  97,036,502  65.96% 
  Sources:  OIG analysis of manufacturer- and distributor-reported sales data and CMSs ASP data, 20102011. 
1  HCPCS codes are in random order.  Because of the datas proprietary status, we could not identify individual 
 
HCPCS codes. 
  2  Figures are shown for only third-quarter 2009; however, the other two quarters under review showed similar 
results. 
 
Some distributors may have sold products in a different quarter than when they purchased 
them, slightly altering the number of units reported to us as compared to the number of 
manufacturer-reported ASP units for each quarter.  However, this is unlikely to account 
for the large disparities in units reported to OIG and CMS.  Rather, it appears likely that 
the data we received were not an accurate representation of the number of sales that 
occurred in the marketplace.  This is evident by the fact that the total number of units 
reported to CMS for all 14 drugs was 66 percent greater than the number of units reported 
to us for those same drugs in that timeframe. 
 
Based on the data we received, it appears that certain manufacturers failed to report ASPs 
to CMS.  The distributors and manufacturers we surveyed reported their sales data by 
NDC.  In those data, we identified many NDCs that were not included in CMSs ASP 
background file.  For example, for the third quarter of 2009, the manufacturers and 
distributors reported sales data to us for 108 unique NDCs that did not have ASPs 
reported to CMS.  These data represented: 
 
  10 of the 14 drugs under review, 
  sold by 44 unique manufacturers, and 
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  totaling $538,000 in sales in third-quarter 2009. 
Of the 108 NDCs not included in CMSs ASP background file that quarter, 83 NDCs  
(77 percent) were sold by manufacturers with Medicaid Rebate Agreements in effect, 
thereby requiring them to report ASP data to CMS.  Sales reported to us for these  
83 NDCs totaled $470,000 in third-quarter 2009.20 
 
Any NDC for which a manufacturer has ever provided ASP data to CMS is included in 
the ASP background file.  Therefore, the absence of these NDCs in the ASP background 
file indicates that there is no record (at least for the purposes of calculating the Medicare 
payment amounts) of these products being sold in the marketplace, despite our survey 
results demonstrating otherwise.  Because CMS uses ASP data to calculate Medicare 
payment amounts, the failure of manufacturers to report these data may result in payment 
amounts that are inaccurate and not reflective of all Part B-covered drug sales. 
 
Most likely because of the issues previously described, the WAMPs we calculated varied 
widely from other pricing points, and therefore we could not accurately determine 
whether any of the drugs exceeded the ASP-WAMP threshold.  As Table 3 shows, ASPs 
for the 14 drugs ranged from 42 percent below the WAMPs to 51 percent above the 
WAMPs in the third quarter of 2009.21  Four of the drugs had ASPs that were more than 
20 percent below the WAMPs we calculated for that quarter.  This particularly calls the 
WAMP datas integrity into question, as WAMPs that are substantially higher than ASPs 
(and AMPs) would likely be indications of widespread provider underreimbursement.  
However, although these drugs consistently appeared in OIGs quarterly pricing 
comparisons as candidates for price reductions, as far as we know, no providers have 
claimed that they are being underreimbursed for the particular products.  These factors 
indicate that our WAMP data (rather than CMSs ASP data) are the most likely cause of 
the ASP-WAMP comparison irregularities, and as a result, our confidence in our WAMP 
calculations has been further eroded. 
 
 
 
 
 
 
 
 
 
                                                 
20 We will refer these manufacturers to CMS and work with it to take appropriate action. 
21 ASPs for the 14 drugs ranged from 36 percent below the WAMPs to 47 percent above the WAMPs in  
fourth-quarter 2009, and from 43 percent below the WAMPs to 49 percent above the WAMPs in first-
quarter 2010. 
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Table 3:  ASP-WAMP and ASP-AMP Comparisons,  
 
  Third-Quarter 2009 
  Percentage Difference  Percentage Difference 
HCPCS Code  Between ASP and WAMP1  Between ASP and AMP 
 
  1*  -41.74%  9.68% 
  2*  -24.27%  5.29% 
 
3*  -23.13%  7.04% 
 
4*  -21.38%  64.14% 
 
5  -10.54%  22.43% 
 
6  -8.08%  7.32% 
 
  7*  -5.80%  449.97% 
  8  -2.92%  9.52% 
 
9  2.08%  6.54% 
 
10  4.18%  6.76% 
 
11  7.05%  6.71% 
 
  12  7.87%  66.92% 
  13  7.94%  9.74% 
 
14*  51.20%  48.32% 
  Sources:  OEI-03-10-00150; OIG analysis of manufacturer- and distributor-reported sales data and 
  CMSs ASP data, 20102011. 
1  Comparisons are shown for only third-quarter 2009; however, the other two quarters under review 
  showed similar results. 
* Denotes HCPCS codes with partial AMP data. 
 
 
CONCLUSION 
 
CMS recently stated that additional analysis of pricing data is an important next step for 
developing a price substitution policy.  The purpose of this review was to assist CMS in 
that effort by comparing ASPs to WAMPs for 14 drugs that have been identified in 
previous OIG reports as repeatedly exceeding the 5-percent ASP-AMP threshold.  
However, limitations and irregularities in the sales data we received prevented us from 
conducting accurate comparisons between ASPs and WAMPs, and as a result, we were 
unable to determine whether any of the drugs exceeded the ASP-WAMP threshold. 
  
The data issues we identified in this report will need to be addressed in any future OIG 
efforts to compare ASPs to WAMPs.  In the past, OIG has collected sales data from 
distributors for studies involving drug pricing in both Medicare and Medicaid.  Discount 
and rebate data have been difficult to obtain from certain respondents, but the lack of data 
on discounts and rebates previously had little influence on our results.  For example, in 
one recent report, OIG was not comparing prices against a set threshold for individual 
drugs.  Rather, we were using the distributor sales data to evaluate an overall pricing 
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policy (i.e., Medicaid Federal upper limits) that resulted in hundreds of millions of dollars 
in excessive payments for more than 550 drugs.22  Because the difference between 
Federal upper limit amounts and acquisition costs was very large (an average of more 
than 300 percent), our pricing comparisons were not inhibited by the lack of data on 
discounts and rebates (and, in fact, additional data on discounts and rebates would have 
widened the spread between acquisition costs and Medicaid payments).  Therefore, in 
that instance, calculating estimated sales prices (rather than exact prices) was appropriate, 
and we noted the lack of price concession data as a limitation.  However, the objectives 
of our WAMP comparisons require more precise estimates of provider acquisition costs, 
and the lack of data on discounts and rebates prevented us from accurately measuring 
WAMPs against the statutory threshold.  In the future, we plan to continue to fulfill our 
statutory mandate to conduct WAMP studies, and we will consider alternative 
methodologies that will allow us to do so, including directly surveying providers to 
obtain accurate and complete sales data. 
 
This report is being issued directly in final form because it contains no recommendations.  
If you have comments or questions about this report, please provide them within 60 days.  
Please refer to report number OEI-03-10-00280 in all correspondence. 
 
                                                 
22 OIG, A Comparison of Medicaid Federal Upper Limit Amounts to Acquisition Costs, Medicare Payment 
Amounts, and Retail Prices (OEI-03-08-00490), August 2009. 
OEI-03-10-00280      Comparison of ASPs to WAMPs for Selected Drugs