DEPARTMENT OF HEALTH & HUMAN SERVICES 	 Office of Inspector General 
Washington, D,C. 20201 
'APR 26 ZOll 
TO: 	 Donald M. Berwick, M.D. 

Administrator 

Centers for Medicare & Medicaid Services 

FROM:  Stuart Wrigh~ 

Deputy Inspector General 

for Evaluation and Inspections 

SUBJECT: 	 Memorandum Report:  Part D Plans Generally Include Drugs Commonly 
Used by Dual Eligibles, OEI-05-10-00390 
This memorandum report fulfills a mandate for 2011 from the Patient Protection and 
Affordable Care Act of2010 (ACA).  The ACA requires that the Office ofInspector 
General (OIG) conduct a study of the extent to which formularies used by stand-alone 
prescription drug plans (PDP) and Medicare Advantage prescription drug plans (MA-PD) 
under Medicare Part 0 include drugs commonly used by full-benefit dual-eligible 
individuals (i.e., individuals who are eligible for both Medicare and Medicaid and who 
receive full Medicaid benefits and assistance with Medicare premiums and cost-sharing). I 
Pursuant to the ACA, beginning July 1, 2011, OIG must annually issue a report with 
recommendations as appropriate.  For the relevant text of the ACA, see Appendix A. 
SUMMARY 
The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA) 
makes comprehensive prescription drug coverage under Medicare Part 0  available to all 
Medicare beneficiaries through POPs and MA-POs (hereinafter referred to collectively as 
Part 0 plans).2 
For beneficiaries who are eligible for both Medicare and Medicaid (hereinafter referred to 
as dual eligibles), Medicare covers Part D plan premiums, deductibles, and other 
cost-sharing up to a determined premium benchmark that varies by region.  If a dual 
eligible enrolls in a Part 0 plan with premiums higher than the regional benchmark, the 
dual eligible is responsible for paying the premium amount above the regional 
benchmark. 
I ACA, P.L. 111-148  3313(a), 42 U.S.C.  1395w-101 note. 

2 MMA, P.L. 108-173  101, Social Security Act,  I 860D-I(a), 42 U.S.C.  1395w-IOI(a). 

OEI-05-10-00390  Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles  Page 2  Donald M. Berwick, M.D. 
 
 
To control costs and ensure the safe use of drugs, Part D plans are allowed to establish 
formularies from which they may omit drugs from prescription coverage and control drug 
utilization through utilization management tools.3  These tools include prior 
authorization, quantity limits, and step therapy.4    
 
The Centers for Medicare & Medicaid Services (CMS) annually reviews Part D plan 
formularies to ensure that they include a range of drugs in a broad distribution of 
therapeutic classes.  CMS also assesses the utilization management tools present in each 
formulary. 
 
For this memorandum report, we determined whether the 249 unique formularies used by 
the 3,072 Part D plans operating in 2011 cover the 200 drugs most commonly used by 
dual eligibles.  We also determined the extent to which those commonly used drugs are 
subject to utilization management tools.  To create the list of the 200 drugs most 
commonly used by dual eligibles, we used the 2007 Medicare Current Beneficiary 
Survey (MCBS).  Of these 200 drugs, 191 are eligible for Part D prescription drug 
coverage and 9 are excluded from coverage. 
 
Overall, we found that the rate of Part D plan formularies inclusion of the 191 drugs 
commonly used by dual eligibles is high, with some variation.  On average, Part D plan 
formularies include 96 percent of the 191 commonly used drugs.  In addition, almost 
60 percent of the commonly used drugs are included by all Part D plan formularies.  
However, we found variation in the rate at which Part D plan formularies apply 
utilization management tools to the drugs commonly used by dual eligibles.  Some Part D 
plan formularies apply these tools to none of the commonly used drugs, whereas at the 
other end of the range, other formularies apply the tools to 45 percent of the commonly 
used drugs.  For CMSs reference, we have included in Appendix D the list of 200 drugs 
commonly used by dual eligibles. 
   
BACKGROUND 
 
The Medicare Prescription Drug Benefit 
Beginning in 2006, the MMA made comprehensive prescription drug coverage under 
Medicare Part D available to all Medicare beneficiaries.5  Medicare beneficiaries 
generally have the option to enroll in a PDP and receive all other Medicare benefits 
                                                 
3 A formulary is a list of drugs covered by a Part D plan.  Part D plans can exclude drugs from their 
formulary and can control drug utilization for drugs on the formulary within certain parameters.  Social 
Security Act  1860D-4(b) & (c), 42 U.S.C.  1395w-104(b) & (c).   
4 Prior authorizationoften required for very expensive drugsrequires that physicians obtain approval 
from Part D plans to prescribe a specific drug.  Quantity limits are intended to ensure that beneficiaries 
receive the proper dose and recommended duration of drug therapy.  Step therapy is the practice of 
beginning drug therapy for a medical condition with the most cost-effective or safest drug therapy and 
progressing if necessary to more costly or risky drug therapy. 
5 MMA, P.L. 108-173  101, Social Security Act,  1860D-1(a), 42 U.S.C.  1395w-101(a). 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 3  Donald M. Berwick, M.D. 
 
 
through fee-for-service, or to enroll in an MA-PD and receive all of their Medicare 
benefits, including prescription drug coverage, through managed care.  As of 
January 2011, almost 30 million of the 46 million Medicare beneficiaries were enrolled in 
a Part D plan.6, 7  
 
Part D plans are administered by private companies, known as plan sponsors, that 
contract with CMS to offer prescription drug coverage in one or more PDP or MA-PD 
regions.  CMS has designated 34 PDP regions and 26 MA-PD regions.8  In 2011, plan 
sponsors offer 3,072 unique Part D plans, with many plan sponsors offering multiple 
Part D plans. 
 
Dual Eligibles Under Medicare Part D 
Approximately 9 million Medicare beneficiaries are dual eligibles.  About 7 million dual 
eligibles, referred to as full-benefit dual eligibles, receive full Medicaid benefits and 
assistance with Medicare premiums and cost-sharing.9  Other dual eligibles receive 
assistance with only their Medicare premiums or cost-sharing, depending on their level of 
income and assets. 
 
Dual eligibles are a particularly vulnerable population.  Overall, these beneficiaries are 
poorer and in worse health than the average Medicare beneficiary.  Most dual eligibles 
have very low incomes:  61 percent have annual incomes below $10,000, compared to 
9 percent of all other Medicare beneficiaries.  Over half of dual eligibles are in fair or 
poor health, twice the rate of others in Medicare.10  As a consequence of their health 
needs, dual eligibles typically require and use more prescription drugs, and more health 
care services in general, than other Medicare beneficiaries. 
 
Until December 31, 2005, dual eligibles received outpatient prescription drug benefits 
through Medicaid.  In January 2006, Medicare began covering outpatient prescription 
drugs for dual eligibles through Part D plans.11   
 
Medicare covers Part D plan premiums, deductibles, and other cost-sharing for dual 
eligibles up to a determined premium benchmark.  The benchmark is a statutorily defined 
amount that is based on the average premium amounts for Part D plans for each 
                                                 
6 CMS, Medicare Advantage, Cost, PACE, Demo, and Prescription Drug Plan Contract ReportMonthly 
Summary Report (data as of January 2011).  Accessed at http://www.cms.hhs.gov on January 20, 2011. 
7 Medicare Board of Trustees, The 2010 Annual Report of the Boards of Trustees of the Federal Hospital 
Insurance and Federal Supplementary Medical Insurance Trust Funds.  Accessed at 
http://www.cms.hhs.gov on January 20, 2011. 
8 CMS, Prescription Drug Benefit Manual (PDBM), Pub. 100-18, ch. 5, Appendixes 3 and 4.  Accessed at 
http://www.cms.hhs.gov on May 5, 2010. 
9 Kaiser Family Foundation, Dual Eligibles:  Medicaids Role for Low-Income Beneficiaries, 
February 2009.  Accessed at http://www.kff.org on May 7, 2010. 
10 Ibid. 
11 MMA, P.L. 108-173  101. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 4  Donald M. Berwick, M.D. 
 
 
region.12, 13  If dual eligibles enroll in Part D plans with premiums higher than the 
regional benchmark, they are responsible for paying the premium amounts above the 
regional benchmark.14   
 
Dual eligibles assignment to Part D plans.  When individuals become eligible for both 
Medicaid and Medicare, CMS randomly assigns those individuals to PDPs unless they 
have elected a specific Part D plan or have opted out of Part D prescription drug 
coverage.15  CMS assigns dual eligibles to PDPs that meet certain requirements, such as 
having a premium at or below the regional benchmark amount and offering basic 
prescription drug coverage (or equivalent).16  Basic prescription drug coverage is defined 
in terms of benefit structure (initial coverage, coverage gap, and catastrophic coverage), 
and costs (initial deductible and coinsurance). 
 
Some dual eligibles may be randomly assigned to Part D plans that do not cover the 
specific drugs they use.  However, unlike the general Medicare population, dual eligibles 
can switch plans at any time to find Part D plans that cover the prescription drugs they 
require.17  When dual eligibles change plans, prescription drug coverage for their new 
Part D plans becomes effective at the beginning of the following month. 
 
CMS annually reassigns some dual eligibles to new PDPs if their current PDPs will have 
premiums above the regional benchmark premium for the following year.18  For dual 
eligibles who were randomly assigned to their current PDPs, CMS reassigns them to new 
PDPs that will have premiums at or below the regional benchmark premium.19  For dual 
eligibles who elected their current Part D plans, CMS notifies them that their plans will 
have premiums above the regional benchmark premium.  According to CMS staff, CMS 
reassigned approximately 900,000 Medicare beneficiaries, including but not exclusively 
dual eligibles, for 2011 because of premium increases. 
                                                 
12 42 CFR.  423.780(b)(2)(i). 
13 Social Security Act,  1860D-14(a)(3)(f), 42 U.S.C.  1395w-114(a)(3)(f).  Dual eligibles residing in 
territories are not eligible to receive cost-sharing assistance from Medicare.  As such, there are no 
benchmarks for Part D plans offered in the territories. 
14 ACA, P.L. 111-148  3303, Social Security Act,  1860D 14(a)(5), 42 U.S.C.  1395w-114(a)(5).  The 
ACA established a de minimis premium policy, whereby a Part D plan may elect to charge dual eligibles 
the benchmark premium amount if the Part D plans basic premium exceeds the regional benchmark by a 
de minimis amount.  For 2011, CMS set the de minimis amount at $2 above the regional benchmark. 
15 PDBM, ch. 3,  30.1.4. 
16 Ibid. 
17 Ibid.,  20.2 and 20.3.  In general, Medicare beneficiaries can switch Part D plans only once a year 
during a defined enrollment period. 
18 Ibid.,  30.1.5. 
19 Ibid. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 5  Donald M. Berwick, M.D. 
 
 
Part D Prescription Drug Coverage 
Under Part D, plans can establish formularies from which they may exclude drugs and 
control drug utilization within certain parameters.  These parameters are intended to 
balance Medicare beneficiaries needs for adequate prescription drug coverage with 
Part D plans needs to contain costs.  Generally, a formulary must include at least two 
drugs in each therapeutic category or class.20, 21  In addition, Part D plans must include 
Part D-covered drugs in certain categories and classes.22 
 
Part D plans may also control drug utilization by applying utilization management tools 
to individual drugs to encourage the use of generic or older drugs and to prevent 
overutilization or underutilization of drugs.  These tools include requiring prior 
authorization to obtain drugs that are on plan formularies, establishing quantity limits, 
and requiring step therapy.23 
 
The MMA mandates that certain categories of drugs be excluded from Medicare Part D 
prescription drug coverage.24  For example, prescription vitamins and mineral products, 
nonprescription drugs, barbiturates, and benzodiazepines are excluded from Part D 
prescription drug coverage.25 
 
CMS Efforts To Ensure Prescription Drug Coverage 
Formulary review.  CMS annually reviews Part D plan formularies to ensure that they 
include a range of drugs in a broad distribution of therapeutic categories or classes and 
include all drugs in specified therapeutic categories or classes.26  During its formulary 
review, CMS analyzes Part D plan formularies coverage of the drug classes most 
commonly prescribed for the Medicare population.  CMS intends for Part D plans to 
cover the most widely used medications, or therapeutically alternative medications (e.g., 
drugs from the same therapeutic category or class), for the most common conditions.  
CMS uses Part D prescription drug data to identify the most commonly prescribed classes 
of drugs.27 
 
CMS also assesses the utilization management tools present in each formulary.28  CMS 
aims to ensure that these tools are consistent with current industry standards and with  
                                                 
20 PDBM, ch. 6,  30.2.1. 
21 Therapeutic categories or classes classify drugs according to their most common intended uses.  For 
example, cardiovascular agents compose a therapeutic class intended to affect the rate or intensity of 
cardiac contraction, blood vessel diameter, or blood volume. 
22 ACA, P.L. 111-148  3307, Social Security Act,  1860D 4(b)(3)(G),  42 U.S.C.  1395w 104(b)(3)(G). 
23 PDBM, ch. 6,  30.2.2. 
24 MMA, P.L. 108-173  101, Social Security Act,  1860D-2(e), 42 U.S.C.  1395w-102(e). 
25 Social Security Act  1860D-2(e)(2), 1927(d)(2), 42 U.S.C.  1395w-102(e)(2), 1396r-8(d)(2). 
26 PDBM, ch. 6,  30.2.1 and 30.2.5. 
27 Ibid.,  30.2.7. 
28 Ibid.,  30.2.2. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 6  Donald M. Berwick, M.D. 
 
 
standards that are widely used with drugs for the elderly and people with disabilities.29, 30  
For example, some drugs may be considered entirely inappropriate for the elderly, while 
others may be considered inappropriate for the elderly at certain dosages or in 
combination with certain other drugs.  Utilization management tools are used to prevent 
the prescription of these drugs, dosages, and combinations. 
 
Exceptions and appeals process.  CMS has implemented an exceptions and appeals 
process whereby beneficiaries can request coverage of nonformulary drugs.  
Beneficiaries apply to their Part D plans for exceptions to obtain coverage of 
nonformulary drugs.  Generally, Part D plans must make determinations within 72 hours 
or, for expedited requests, within 24 hours.31  If their Part D plans make negative 
determinations, beneficiaries have the right to appeal.32  If their Part D plans deny their 
appeals, beneficiaries would need to get prescriptions from their physicians for 
therapeutically alternative drugs that are covered by their Part D plans. 
 
Transitioning new enrollees to Part D.  CMS requires that Part D plans establish a 
transition process for new enrollees (including dual eligibles) who are transitioning to 
Part D from other prescription drug coverage.  During Medicare beneficiaries first 
90 days under a new Part D plan, the new plan must provide one temporary fill of a 
prescription when beneficiaries request either a drug that is not in the plans formulary or 
a drug that requires prior authorization or step therapy under the formularys utilization 
management tools.33  The temporary fill accommodates beneficiaries immediate drug 
needs the first time they attempt to fill a prescription.  The transition period also allows 
beneficiaries time to work with their prescribing physicians to obtain prescriptions for 
therapeutically alternative drugs or request formulary exceptions from Part D plans. 
 
Related Office of Inspector General Work  
In 2006, OIG published a report assessing the extent to which PDP formularies included 
drugs commonly used by dual eligibles under Medicaid.  The study found that PDP 
formularies included between 76 and 100 percent of the 178 commonly used drugs that 
we reviewed.  Approximately half of the 178 commonly used drugs were covered by all 
formularies.34 
                                                 
29 PDBM, ch. 6,  30.2.2. 
30 CMS looks to appropriate guidelines that might be found from expert organizations such as the National 
Committee for Quality Assurance, the Academy of Managed Care Pharmacy, and the National Association 
of Insurance Commissioners. 
31 PDBM, ch. 18,  130.1 and 130.2. 
32 Ibid.,  60.1. 
33 Ibid., ch. 6,  30.4.4. 
34 OIG, Dual Eligibles Transition:  Part D Formularies Inclusion of Commonly Used Drugs, 
OEI-05-06-00090, January 2006. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 7  Donald M. Berwick, M.D. 
 
 
METHODOLOGY 
 
Scope 
As mandated in the ACA, this study assessed the extent to which drugs commonly used 
by dual eligibles are available on Part D plan formularies.  To make this assessment, we 
evaluated formularies for Part D plans operating in 2011.  As part of our assessment, we 
included dual eligibles enrollment data from February 2011, the most recent enrollment 
data available from CMS at the time of our study.   
 
The ACA did not define which drugs commonly used by dual eligibles we should review.  
We defined drugs commonly used by dual eligibles as the 200 drugs with the highest 
utilization by dual eligibles as reported in the 2007 MCBS.  We used the MCBS because 
it contains drugs that dual eligibles received through multiple sources (e.g., Part D, 
Medicaid, and the Department of Veterans Affairs) and, as such, it provides a 
comprehensive picture of drug utilization.  Of the 200 most commonly used drugs 
identified using the MCBS, 191 are eligible under Part D.   
 
This study went beyond the ACAs mandate by reviewing drug coverage for all dual 
eligibles under Medicare Part D, rather than only for full-benefit dual eligibles.  With the 
data available for this study, we could not confidently identify full-benefit dual eligibles 
and the drugs they used.  However, dual eligibles represent a vulnerable population as a 
whole, and 80 percent of dual eligibles are full-benefit dual eligibles.  
 
We also went beyond the ACAs mandate by examining the utilization management tools 
that Part D plan formularies apply to the drugs commonly used by dual eligibles.  
Because these utilization management tools are used to influence drug utilization, they 
may affect dual eligibles access in cases where formularies include the commonly used 
drugs.  Analyzing the extent to which Part D plan formularies apply utilization 
management tools to drugs commonly used by dual eligibles allows us to provide a 
comprehensive picture of Part D plan formularies coverage of, and dual eligibles access 
to, those drugs. 
 
Data Sources 
MCBS.  We used 2007 MCBS Cost and Use data to create a list of 200 drugs commonly 
used by dual eligibles.  The MCBS Cost and Use data contain information on hospitals, 
physicians, and prescription drug costs and utilization.  The 2007 MCBS Cost and Use 
data are the most recent data available.   
 
The MCBS is a CMS-conducted continuous, multipurpose survey of a representative 
national sample of the Medicare population, including dual eligibles.  Sampled Medicare 
beneficiaries are interviewed three times per year and asked what drugs they are taking 
and whether they have started taking any new drugs since the previous interview.  The 
MCBS also includes Part D prescription drug events for surveyed Medicare beneficiaries.  
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 8  Donald M. Berwick, M.D. 
 
 
In 2007, the MCBS surveyed 11,995 Medicare beneficiaries, of which 2,324 were dual 
eligibles who had used prescription drugs during the year (out of a total of 
2,555 dual-eligible survey respondents). 
 
First Databank National Drug Data File.  We used the January 2011 First DataBank 
National Drug Data File to identify the drug product information for the drugs on our list 
of 200 drugs commonly used by dual eligibles.  The National Drug Data File is a 
database containing informationsuch as drug name, therapeutic class, and the unique 
combination of active ingredientsfor each drug defined by the Food and Drug 
Administrations (FDA) National Drug Code (NDC).  (An NDC is a three-part universal 
identifier that specifies the drug manufacturers name, the drug form and strength, and 
the package size.) 
 
Part D plan data.  From CMS, we collected Part D plan and formulary data for Part D 
plans operating in 2011.  The 2011 Part D plan data provide information such as the State 
in which a Part D plan is offered, whether the Part D plan is a PDP or an MA-PD, and 
whether the Part D plan premium is below the regional benchmark.  The 2011 Part D 
formulary data include Part D plans formularies and utilization management tools.  In 
2011, there are 249 unique formularies offered by the 3,072 Part D plans.   
 
We also collected 2011 Part D plan enrollment data.  These data provide the number of 
dual eligibles enrolled in each Part D plan as of February 2011.   
 
Determining Most Commonly Used Drugs 
To determine the drugs most commonly used by dual eligibles, we took the following 
steps: 
 
1.  Created a list of all drugs reported by dual eligibles surveyed in the MCBS.  We 
excluded respondents from territories because they are not eligible to receive 
cost-sharing assistance under Part D.  There were 164,926 drug events listed for 
2,324 dual eligibles in the MCBS. 
 
2.  Collapsed this list to a list of drugs based on their active ingredients, using the 
Ingredient List Identifier located in First DataBanks National Drug Data File.  
For example, a multiple-source drug such as fluoxetine hydrochloride (the active 
ingredient for the multiple-source brand-name drug Prozac) has only one entry on 
our list, covering all strengths of both the brand-name drug Prozac and the generic 
versions of fluoxetine hydrochloride available.  From this point forward, unless 
otherwise stated, we will use the term drug to refer to any drug in the same 
Ingredient List Identifier category, and the term unique drug to refer to an NDC 
corresponding to a drug.  (A given drug can have multiple NDCs.)  This process 
left 163,554 drug events associated with 910 drugs.  (There were 1,372 drug 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 9  Donald M. Berwick, M.D. 
 
 
events in the MCBS that could not be matched with an Ingredient List Identifier 
in First DataBanks National Drug Data File.)   
 
3.  Ranked all drugs by their frequency of utilization based on weighting from the 
MCBS sample design.   
 
4.  Selected the 200 drugs with the highest utilization by dual eligibles. 
 
5.  Removed all drugs excluded under Part D.  Of the 200 drugs with the highest 
utilization, 191 are eligible under Part D and 9 fell into drug categories excluded 
under Part D.  For a list of the nine excluded drugs, see Appendix B. 
 
Formulary Analysis 
We analyzed the 249 unique Part D plan formularies to determine formulary inclusion 
rates for the 191 drugs commonly used by dual eligibles.  We counted a drug as included 
in a Part D plans formulary if the formulary included the active ingredient category.  
When a drug included multiple ingredients, and the ingredients could be dispensed 
separately and combined by the patient to the same effect as the combined drug, then we 
treated the drug as included if the ingredients were included in the formulary either 
separately or in combination.   
 
Utilization management tools.  In addition, we determined the extent to which Part D 
plans apply utilization management tools to the 191 drugs that we reviewed.  The tools 
that we reviewed are prior authorization, quantity limits, and step therapy. 
 
To determine the extent to which the 191 commonly used drugs are subject to utilization 
management tools, we conducted an analysis of the NDCs that correspond to the 
commonly used drugs.  Part D plan formularies do not apply utilization management 
tools at the active ingredient level.  Rather, Part D plan formularies apply utilization 
management tools at a more specific level that identifies whether a drug is brand-name or 
generic and provides its dosage form, strength, and route of administration, irrespective 
of package size.  To conduct this analysis, we determined the NDCs (unique drugs) 
associated with each of the 191 commonly used drugs that are on each Part D formulary.  
We then calculated the percentage of unique drugs that each Part D plan formulary covers 
with utilization management tools.  
 
Enrollment Analysis 
We also weighted both the formulary and utilization management tool analysis by 
enrollment by dual eligibles.  To do so, we applied February 2011 enrollment data to 
2011 Part D plans.   
 
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Data Limitations 
We did not assess individual dual eligibles prescription drug use or whether individual 
dual eligibles are enrolled in Part D plans that include the specific drugs that each 
individual uses.  Because we relied on a sample of dual eligibles responding to the MCBS 
to develop our list of commonly used drugs, it is possible that a particular dual eligible 
might not use any of the drugs on our list.  However, the drugs most commonly used by 
dual-eligible MCBS survey participants in 2007 account for 87 percent of all 
prescriptions dispensed to the dual-eligible respondents in the 2007 MCBS.    
 
In addition, more than 80 percent of the commonly used drugs were on the list of drugs 
commonly used by dual eligibles in the 2006 OIG report Dual Eligibles Transition:  
Part D Formularies Inclusion of Commonly Used Drugs, OEI-05-06-00090.  For the 
2006 OIG report, we used Medicaid drug utilization data from 2005 to create the list of 
drugs commonly used by dual eligibles, as those data were the most recent available. 
 
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 
 
Part D Plan Formularies Include Between 82 and 100 Percent of the Drugs 
Commonly Used by Dual Eligibles 
On average, Part D plan formularies include 96 percent of the drugs commonly used by 
dual eligibles.  Of the 249 unique formularies used by Part D plans in 2011, 14 percent 
include all of the commonly used drugs.  At the other end of the range, two formularies 
include less than 85 percent of the commonly used drugs.  CMS generally requires Part D 
plan formularies to include at least two drugs, rather than all drugs, in each therapeutic 
category or class.  Therefore, Part D plan formularies may include drugs that are not 
identified as commonly used by dual eligibles and still meet CMSs formulary 
requirements.   
 
Formularies used by PDPs or MA-PDs have the same average rates of inclusion of the 
commonly used drugs.  On average, formularies used by either PDPs or MA-PDs include 
96 percent of the commonly used drugs.  PDP formulary inclusion ranges from 88 to 
100 percent of the commonly used drugs.  The range of formulary inclusion is slightly 
larger for MA-PDs, ranging from 82 to 100 percent.  Twelve percent of formularies are 
offered by both PDPs and MA-PDs.   
 
All dual eligibles throughout the country have the choice of a Part D plan that includes at 
least 98 percent of the commonly used drugs.  Every PDP region has a plan that includes 
at least 99 percent of the commonly used drugs and every MA-PD region has a plan that 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 11  Donald M. Berwick, M.D. 
 
 
covers at least 98 percent.  Appendix C provides a breakdown of formulary inclusion by 
PDP and MA-PD region. 
 
On average, formularies for Part D plans with premiums below the regional benchmark 
include 95 percent of the drugs commonly used by dual eligibles.  The number of drugs 
included by Part D plans with premiums below the regional benchmark is important 
because dual eligibles are automatically enrolled in, or annually reassigned to, these 
plans.  On average, formularies for Part D plans with premiums below the regional 
benchmark include 95 percent of the drugs commonly used by dual eligibles.  Like 
formularies for Part D plans overall, formularies for Part D plans with premiums below 
the regional benchmark have a rate of inclusion for drugs commonly used by dual 
eligibles that ranges from a low of 82 percent to a high of 100 percent.  Approximately 
79 percent of dual eligibles are enrolled in Part D plans with premiums below the 
regional benchmark.     
 
Ninety percent of dual eligibles are enrolled in Part D plans that include at least 
90 percent of the drugs commonly used by dual eligibles.  Of the approximately 9 million 
dual eligibles, 90 percent are enrolled in Part D plans that use formularies that include at 
least 90 percent of the commonly used drugs.  Only 1 percent of dual eligibles are 
enrolled in Part D plans that use formularies that include less than 85 percent of the 
commonly used drugs.  Table 1 provides a breakdown of dual eligibles enrollment in 
Part D plans by the plans formulary inclusion rates. 
 
 
Table 1:  Enrollment of Dual Eligibles in Part D Plans and Formulary Inclusion   
of Commonly Used Drugs   
 
Number of Dual Eligibles  Percentage of Dual 
Part D Plans That Include: 
Enrolled*  Eligibles Enrolled   
 
100% of commonly used drugs  229,000  3% 
 
 
95% to 99% of commonly used drugs  5,108,000  56% 
 
90% to 94% of commonly used drugs  2,786,000  31%   
 
85% to 89% of commonly used drugs  851,000  9% 
 
Less than 85% of commonly used drugs  75,000  1%   
 
     Totals  9,049,000  100% 
 
*Rounded to the nearest 1,000.   
Source:  OIG analysis of formulary inclusion of drugs commonly used by dual eligibles and dual eligibles enrollment, 2011.   
 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 12  Donald M. Berwick, M.D. 
 
 
Almost 60 Percent of the Drugs Commonly Used by Dual Eligibles Are Included in 
All Part D Plan Formularies 
Because most of the commonly used drugs are included in a large percentage of 
formularies, dual eligibles are guaranteed formulary inclusion of many of these drugs 
regardless of the Part D plan in which they are enrolled.  In fact, 58 percent of the drugs 
commonly used by dual eligibles are included in all 249 formularies.  An additional 
11 percent of these commonly used drugs are included in all but one or two formularies.  
 
By drug, formulary inclusion ranges from 30 percent to 100 percent.  In other words, one 
drug commonly used by dual eligibles is included in as few as 30 percent of Part D plan 
formularies, and others are included in all plan formularies.  The average rate of 
formulary inclusion is 96 percent.  Table 2 provides a summary of formulary inclusion 
rates.  Appendix D provides formulary inclusion rates for each of the commonly used 
drugs. 
 
  Table 2:  Formulary Inclusion Rates of Commonly 
  Used Drugs 
  Percentage of the  Percentage of the 191 Commonly 
  249 Formularies  Included Drugs 
  58%  
100%  
  (111 drugs) 
  35% 
85% to 99%  
   (67 drugs) 
  3%  
75% to 84%  
(5 drugs) 
 
  30% to 74%   4%  
(8 drugs) 
 
100%  
       Total 
(191 drugs) 
 
Source:  OIG analysis of formulary inclusion of drugs commonly used by dual 
 
eligibles, 2011. 
 
 
Part D plan formularies include certain drugs less frequently than others.  Of the 
commonly used drugs, 4 percent (eight drugs) are included by less than 75 percent of 
Part D plan formularies.  Table 3 provides the percentage of formularies covering each of 
these eight drugs.  Six of the eight drugs are brand-name drugs, which are typically more 
costly than generic drugs.  Three of the eight drugs are used to treat high blood pressure 
and two are used to lower cholesterol. 
 
 
 
 
 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 13  Donald M. Berwick, M.D. 
 
 
 
Table 3:  Drugs Included by Less Than 75 Percent of Part D Plan Formularies 
Formulary 
Generic Name of Drug  Primary Indication(s) 
Inclusion Rate 
Olmesartan medoxomil  Hypertension (high blood pressure)  69% 
Ezetimibe/simvastatin  Hyperlipidemia (high cholesterol)  64% 
Propoxyphene/acetaminophen*  Pain relief  59% 
Eszopiclone  Insomnia  58% 
Irbesartan  Hypertension (high blood pressure)  50% 
Irbesartan/hydrochlorothiazide  Hypertension (high blood pressure)  49% 
Fluvastatin sodium  Hyperlipidemia (high cholesterol)  47% 
Gastroesophageal reflux disease, ulcers, and 
Rabeprazole sodium  30% 
Zollinger-Ellison syndrome 
* In November 2010, FDA requested that drug makers voluntarily withdraw propoxyphene/acetaminophen from the market 
because of serious or fatal heart risks.  According to FDA, drug makers agreed to this request. 
Source:  OIG analysis of formulary inclusion of drugs commonly used by dual eligibles, 2011. 
 
Although Part D plan formularies frequently omit these eight drugs, they all cover other 
therapeutically alternative drugs.  For each of the eight drugs, 100 percent of formularies 
cover at least one therapeutically alternative drug.  For seven of the eight drugs, 
100 percent of formularies cover at least one therapeutically alternative drug that is also 
on the list of 191 drugs commonly used by dual eligibles. 
 
There are several means by which dual eligibles can obtain a nonformulary drug, all of 
which require them to take additional action.  Obtaining therapeutically alternative drugs 
requires that dual eligibles get new prescriptions from their doctors.  Dual eligibles may 
also submit statements of medical necessity from their physicians as part of appeals to 
obtain coverage of nonformulary drugs.  Finally, dual eligibles may switch to Part D 
plans that include their drugs (with the new coverage effective the following month). 
 
Part D Plan Formularies Vary in the Rate at Which They Apply Utilization 
Management Tools to the Drugs Commonly Used by Dual Eligibles 
The rate at which Part D plan formularies apply utilization management tools varies from 
between 0 and 45 percent of the unique drugs.  On average, Part D plan formularies apply 
utilization management tools to 19 percent of the unique drugs that compose the drugs 
commonly used by dual eligibles.  Utilization management tools can help Part D plans 
and the Part D program limit the cost of drug coverage and can help prevent the 
overutilization or underutilization of certain drugs.  Formularies for Part D plans with 
premiums below the regional benchmark apply utilization management tools at the same 
rates as Part D plan formularies overall. 
  
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 14  Donald M. Berwick, M.D. 
 
 
Part D plan formularies also vary in the rate at which they apply individual utilization 
management tools.  The rate at which Part D plan formularies apply quantity limits, the 
most frequently applied utilization management tool, varies from between zero and 
45 percent of the unique drugs.  The rates at which Part D plan formularies apply prior 
authorization and step therapy vary from 0 to 35 percent and 0 to 22 percent, 
respectively. 
 
Although Part D plan formularies vary in the rates at which they apply utilization 
management tools, Part D plan formularies mostly apply these tools to brand-name drugs.  
Sixty-four percent of the unique drugs to which Part D plan formularies apply utilization 
management tools are brand-name drugs.  Limiting brand-name drug utilization can help 
Part D plans minimize the cost of drug coverage. 
 
The majority of dual eligibles are enrolled in Part D plans that apply utilization 
management tools to at least 20 percent of the unique drugs composing the commonly 
used drugs.  Fifty-eight percent of dual eligibles are enrolled in Part D plans that use 
formularies that apply utilization management tools to at least 20 percent of the unique 
drugs.  By comparison, 53 percent of all Medicare beneficiaries are enrolled in these 
same Part D plans.  Eighteen percent of dual eligibles are enrolled in Part D plans that use 
formularies that apply utilization management tools to at least 40 percent of the unique 
drugs.  Table 4 provides a breakdown of dual eligibles enrollment in Part D plans by the 
plans application of utilization management tools. 
 
  Table 4:  Beneficiary Enrollment and Part D Plan Formularies 
 
Application of Utilization Management Tools to Commonly Used 
 
Drugs 
 
Percentage of 
Percentage of Unique Drugs to  Number of  Percentage of 
  Medicare 
Which Utilization Management  Part D Plan  Dual Eligibles 
  Beneficiaries 
Tools Are Applied  Formularies  Enrolled 
Enrolled 
 
  40% to 45%   14  18%  12% 
 
30% to 39%   29  14%  24% 
 
  20% to 29%   75  26%  17% 
 
10% to 19%   76  39%  39% 
 
 
Less than 10%   55  4%  7% 
 
       Totals  249  100*%  100%* 
 
*Percentages do not add to 100 percent because of rounding. 
  Source:  OIG analysis of formulary inclusion of drugs commonly used by dual eligibles and dual eligible 
  enrollment, 2011. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 15  Donald M. Berwick, M.D. 
 
 
CONCLUSION 
 
When establishing formularies and applying utilization management tools, Part D plans 
need to balance Medicare beneficiaries needs for adequate prescription drug coverage 
with the need to contain costs for themselves and for the Part D program.  Part D plan 
formularies do not have to include every available drug; rather, to meet CMSs formulary 
requirements, they must include at least two drugs in each therapeutic category or class.  
For example, for each of the eight drugs that this report identifies as being included by 
less than 75 percent of Part D plan formularies, all Part D plan formularies cover at least 
one therapeutically alternative drug.  Part D plan formularies may also institute utilization 
management tools to ensure appropriate utilization as well as to control costs. 
 
For the drugs commonly used by dual eligibles, we found that the rate of formulary 
inclusion is high with some variation.  On average, Part D plan formularies include 
96 percent of the commonly used drugs.  A few Part D plan formularies include as few as 
82 percent of the commonly used drugs.  Formulary inclusion rates are similar 
irrespective of whether Part D plans are PDPs or MA-PDs.  Further, formularies for 
Part D plans with premiums below the regional benchmark include the commonly used 
drugs at the same rate as Part D plan formularies overall. 
 
We found greater variation in the rate at which Part D plan formularies apply utilization 
management tools to the unique drugs that compose the drugs commonly used by dual 
eligibles.  Some Part D plan formularies apply utilization management tools to none of 
the unique drugs, whereas others apply utilization management tools to 45 percent of the 
unique drugs.   
 
Because some variation exists both in Part D plan formularies inclusion of the 
commonly used drugs and in their application of utilization management tools to these 
drugs, some dual eligibles may need to navigate the options available for accessing the 
drugs they take.  They could do so by appealing prescription drug coverage decisions, 
switching prescription drugs, or switching Part D plans.  Any of these scenarios requires 
dual eligibles to have a certain level of understanding of Medicare Part D.  Dual eligibles 
may have to take specific actions that are minor administrative barriers to some and 
major barriers to others.   
 
As mandated by the ACA, OIG will continue to monitor the extent to which Part D plan 
formularies cover drugs that dual eligibles commonly use.  In addition, OIG will continue 
to monitor Part D plan formularies application of utilization management tools to these 
drugs.   
 
This report is being issued directly in final form because it contains no recommendations.  
For CMSs reference, we have included the list of the 200 drugs most commonly used by 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 16  Donald M. Berwick, M.D. 
 
 
dual eligibles.  If you have comments or questions about this report, please provide them 
within 60 days.  Please refer to report number OEI-05-10-00390 in all correspondence. 
 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 17  Donald M. Berwick, M.D. 
 
 
APPENDIX A 
 
Section 3313 of the Patient Protection and Affordable Care Act of 2010 
 
SEC. 3313. OFFICE OF THE INSPECTOR GENERAL STUDIES AND REPORTS. 
 
(a)  STUDY AND ANNUAL REPORT ON PART D FORMULARIES INCLUSION 
OF DRUGS COMMONLY USED BY DUAL ELIGIBLES. 
 
(1)   STUDY.The Inspector General of the Department of Health and Human Services 
shall conduct a study of the extent to which formularies used by prescription drug plans 
and MA-PD plans under Part D include drugs commonly used by full benefit dual 
eligible individuals (as defined in section 1935(c)(6) of the Social Security Act 
(42 U.S.C. 1396u5(c)(6)). 
 
(2)  ANNUAL REPORTS.Not later than July 1 of each year (beginning with 2011), the 
Inspector General shall submit to Congress a report on the study conducted under 
paragraph (1), together with such recommendations as the Inspector General determines 
appropriate. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 18  Donald M. Berwick, M.D. 
 
 
APPENDIX B 
 
Nine Drugs Commonly Used by Dual Eligibles and Excluded Under Part D 
 
Reason Excluded Under 
Generic Name 
Part D 
Alprazolam  Benzodiazepine 
Cetirizine hydrochloride  Non-prescription drug 
Clonazepam  Benzodiazepine 
Diazepam  Benzodiazepine 
Folic acid  Vitamin or mineral product 
Lorazepam  Benzodiazepine 
Omeprazole magnesium  Non-prescription drug 
Polyethylene glycol 3350  Non-prescription drug 
Temazepam  Benzodiazepine 
Source:  Office of Inspector General analysis of formulary inclusion of drugs commonly 
used by dual eligibles, 2011. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 19  Donald M. Berwick, M.D. 
 
 
APPENDIX C 
 
Formulary Inclusion of Stand-Alone Prescription Drug Plans* and Medicare 
Advantage Prescription Drug Plans** by Regions 
Table C-1:  PDP Formulary Inclusion 
PDP  Number of  Average Formulary  Minimum  Maximum 
State(s) 
Region  PDPs  Inclusion Rate9  Rate  Rate 
1  Maine, New Hampshire  30  95%  88%  99% 
Connecticut, Massachusetts, Rhode 
2  34  95%  88%  100% 
Island, Vermont 
3  New York  33  95%  88%  100% 
4  New Jersey  33  95%  88%  100% 
Delaware, the District of Columbia, 
5  33  95%  88%  100% 
Maryland 
6  Pennsylvania, West Virginia  38  95%  88%  100% 
7  Virginia  32  95%  88%  99% 
8  North Carolina  33  95%  88%  100% 
9  South Carolina  34  95%  88%  99% 
10  Georgia  32  95%  88%  99% 
11  Florida  32  95%  88%  100% 
12  Alabama, Tennessee  34  95%  88%  99% 
13  Michigan  35  95%  88%  100% 
14  Ohio  34  95%  88%  100% 
15  Indiana, Kentucky  32  95%  88%  100% 
16  Wisconsin  32  95%  88%  99% 
17  Illinois  35  95%  88%  100% 
18  Missouri  32  95%  88%  100% 
19  Arkansas  34  95%  88%  99% 
20  Mississippi  32  95%  88%  99% 
21  Louisiana  32  95%  88%  100% 
22  Texas  33  95%  88%  100% 
23  Oklahoma  33  95%  88%  99% 
24  Kansas  33  95%  88%  99% 
Iowa, Minnesota, Montana, Nebraska, 
25  33  95%  88%  99% 
North Dakota, South Dakota, Wyoming 
26  New Mexico  32  95%  88%  100% 
27  Colorado  31  95%  88%  100% 
28  Arizona  30  95%  88%  100% 
29  Nevada  31  95%  88%  100% 
30  Oregon, Washington  32  95%  88%  100% 
continued on next page 
       *PDP. 
       **MA-PD. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 20  Donald M. Berwick, M.D. 
 
 
Table C-1:  PDP Formulary Inclusion, continued 
PDP  Number of  Average Formulary  Minimum  Maximum 
State(s) 
Region  PDPs  Inclusion Rate9  Rate  Rate 
31  Idaho, Utah  35  95%  88%  99% 
32  California  33  95%  88%  100% 
33  Hawaii  28  95%  88%  100% 
34  Alaska  29  95%  88%  99% 
Source:  Office of Inspector General (OIG) analysis of formulary inclusion of drugs commonly used by dual eligibles, 2011. 
 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 21  Donald M. Berwick, M.D. 
 
 
 
Table C-2:  MA-PD Formulary Inclusion by Region 
MA-PD  Number of  Average Formulary  Minimum  Maximum 
State(s) 
Region*  MA-PDs  Inclusion Rate9  Rate  Rate 
1  Maine, New Hampshire  29  96%  91%  99% 
Connecticut, Massachusetts, Rhode 
2  55  97%  92%  100% 
Island, Vermont 
3  New York  173  97%  91%  100% 
4  New Jersey  30  95%  91%  100% 
Delaware, the District of Columbia, 
5  37  93%  82%  98% 
Maryland 
6  Pennsylvania, West Virginia  126  97%  88%  100% 
7  North Carolina, Virginia  110  96%  82%  100% 
8  Georgia, South Carolina  113  96%  82%  99% 
9  Florida  242  97%  85%  100% 
10  Alabama, Tennessee  81  96%  91%  98% 
11  Michigan  56  97%  90%  100% 
12  Ohio  71  96%  82%  100% 
13  Indiana, Kentucky  70  97%  91%  99% 
14  Illinois, Wisconsin  123  97%  86%  100% 
15  Arkansas, Missouri  100  96%  91%  100% 
16  Louisiana, Mississippi  84  96%  91%  100% 
17  Texas  146  96%  91%  99% 
18  Kansas, Oklahoma  53  97%  91%  100% 
Iowa, Minnesota, Montana, Nebraska, 
19  109  97%  88%  100% 
North Dakota, South Dakota, Wyoming 
20  Colorado, New Mexico  57  95%  82%  100% 
21  Arizona  71  95%  89%  100% 
22  Nevada  42  96%  91%  100% 
23  Idaho, Oregon, Utah, Washington  153  96%  82%  100% 
24  California  213  95%  82%  100% 
25  Hawaii  18  94%  82%  98% 
*Region 26, which covers Alaska, has no MA-PDs available for 2011. 
Source:  OIG analysis of formulary inclusion of drugs commonly used by dual eligibles, 2011. 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 22  Donald M. Berwick, M.D. 
 
 
APPENDIX D 
 
Commonly Used Drugs and Formulary Inclusion 
Table D-1:  200 Drugs Commonly Used by Dual Eligibles 
Number of  Percentage of 
Sample  Projected  95-Percent Confidence 
Generic Name  Formularies  Formularies 
Size*  Drugs*  Interval*9  Including  Including 
Furosemide  4,077  12,777,427  11,494,529 - 14,060,326  249  100% 
Lisinopril  3,580  12,151,502  10,576,310 - 13,726,694  249  100% 
Levothyroxine sodium  3,589  11,127,522  9,954,546 - 12,300,497  249  100% 
Hydrocodone bit/acetaminophen  3,620  10,565,039  9,157,245 - 11,972,832  249  100% 
Potassium chloride  2,995  9,539,793  8,192,121 - 10,887,464  249  100% 
Atorvastatin calcium  2,769  9,511,085  8,153,698 - 10,868,472  219  88% 
Metformin hydrochloride (HCl)  2,451  9,337,868  7,956,543 - 10,719,194  249  100% 
Simvastatin  2,572  8,787,495  7,703,775 - 9,871,216  248  100% 
Amlodipine besylate  2,182  7,058,486  6,087,271 - 8,029,700  249  100% 
Omeprazole  2,215  7,025,621  6,049,913 - 8,001,330  247  99% 
Atenolol  1,995  7,014,178  5,799,615 - 8,228,742  249  100% 
Warfarin sodium  2,327  6,816,713  5,528,604 - 8,104,823  249  100% 
Albuterol sulfate  1,995  6,527,476  5,303,260 - 7,751,692  249  100% 
Clopidogrel bisulfate  1,908  6,517,472  5,554,124 - 7,480,821  249  100% 
Metoprolol tartrate  1,916  6,040,847  5,115,012 - 6,966,682  249  100% 
Metoprolol succinate  1,765  5,707,503  4,793,878 - 6,621,128  247  99% 
Hydrochlorothiazide  1,743  5,616,691  4,823,923 - 6,409,460  249  100% 
Esomeprazole magnesium 
1,518  4,734,962  3,874,345 - 5,595,578  189  76% 
trihydrate 
Lansoprazole  1,503  4,612,946  3,647,598 - 5,578,293  211  85% 
Gabapentin  1,411  4,511,832  3,754,739 - 5,268,925  249  100% 
Glipizide  1,194  4,360,420  3,538,784 - 5,182,055  249  100% 
Diltiazem HCl  1,247  4,118,699  3,359,488 - 4,877,910  249  100% 
Escitalopram oxalate  1,385  3,952,017  3,273,236 - 4,630,798  222  89% 
Sertraline HCl  1,447  3,923,532  3,334,070 - 4,512,993  249  100% 
Ranitidine HCl  1,277  3,653,877  3,002,661 - 4,305,092  249  100% 
Oxycodone HCl/acetaminophen  1,218  3,635,428  2,811,065 - 4,459,792  249  100% 
Quetiapine fumarate  1,503  3,626,187  2,842,454 - 4,409,919  249  100% 
Alendronate sodium  954  3,560,263  2,863,184 - 4,257,341  249  100% 
Montelukast sodium  1,127  3,509,414  2,669,878 - 4,348,950  248  100% 
continued on next page 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 23  Donald M. Berwick, M.D. 
 
 
 
Table D-1:  200 Drugs Commonly Used by Dual Eligibles, continued 
Number of  Percentage of 
Sample  Projected  95-Percent Confidence 
Generic Name  Formularies  Formularies 
Size*  Drugs*  Interval*9  Including  Including 
Fluticasone/salmeterol  1,030  3,470,763  2,735,303 - 4,206,224  247  99% 
Isosorbide mononitrate  1,086  3,458,585  2,741,228 - 4,175,942  249  100% 
Pantoprazole sodium  949  3,394,600  2,671,993 - 4,117,207  200  80% 
Donepezil HCl  1,164  3,393,695  2,895,181-  3,892,210  233  94% 
Digoxin  1,031  3,371,050  2,704,365 - 4,037,735  249  100% 
Trazodone HCl  1,165  3,334,296  2,638,788 - 4,029,804  249  100% 
Paroxetine HCl  1,013  3,334,072  2,566,110 - 4,102,033  249  100% 
Divalproex sodium  1,460  3,313,752  2,554,887 - 4,072,618  249  100% 
Zolpidem tartrate  1,048  3,133,709  2,513,629 - 3,753,788  247  99% 
Alprazolam  957  3,126,563  2,527,121 - 3,726,005  Excluded  Excluded 
Risperidone  1,350  3,104,611  2,434,354 - 3,774,868  249  100% 
Carvedilol  887  3,074,987  2,454,495 - 3,695,480  249  100% 
Pioglitazone HCl  830  3,063,261  2,395,363 - 3,731,158  249  100% 
Valsartan  948  3,053,856  2,398,364 - 3,709,348  238  96% 
Clonidine HCl  949  3,004,950  2,445,603 - 3,564,296  249  100% 
Fluticasone propionate  841  2,892,719  2,333,605 - 3,451,833  249  100% 
Risedronate sodium  777  2,891,758  2,168,585 - 3,614,931  195  78% 
Citalopram hydrobromide  1,024  2,877,584  2,031,680 - 3,723,489  248  100% 
Propoxyphene/acetaminophen  918  2,751,015  2,258,560 - 3,243,471  147  59% 
Enalapril maleate  817  2,731,343  2,163,046 - 3,299,640  249  100% 
Tramadol HCl  914  2,729,513  2,217,482 - 3,241,544  249  100% 
Prednisone  948  2,727,256  2,262,168 - 3,192,343  249  100% 
Venlafaxine HCl  855  2,636,123  1,658,931 - 3,613,316  249  100% 
Insulin glargine, human 
870  2,621,879  2,042,038 - 3,201,721  234  94% 
recombinant analog 
Olanzapine  1,039  2,615,352  1,970,439 - 3,260,266  249  100% 
Ezetimibe/simvastatin  701  2,557,026  1,998,199 - 3,115,853  160  64% 
Glyburide  740  2,459,147  1,854,805 - 3,063,488  248  100% 
Lovastatin  668  2,436,700  1,821,359 - 3,052,040  240  96% 
Metoclopramide HCl  593  2,394,861  1,530,517 - 3,259,205  249  100% 
Amitriptyline HCl  693  2,369,238  1,767,592 - 2,970,884  249  100% 
continued on next page 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 24  Donald M. Berwick, M.D. 
 
 
 
Table D-1:  200 Drugs Commonly Used by Dual Eligibles, continued 
Number of  Percentage of 
Sample  Projected  95-Percent Confidence 
Generic Name  Formularies  Formularies 
Size*  Drugs*  Interval*9  Including  Including 
Ibuprofen  754  2,271,424  1,779,250 - 2,763,598  249  100% 
Nitroglycerin  734  2,213,718  1,754,009 - 2,673,427  249  100% 
Triamterene/hydrochlorothiazide  751  2,207,727  1,756,978 - 2,658,477  249  100% 
Fluoxetine HCl  860  2,195,279  1,797,853 - 2,592,704  249  100% 
Rosiglitazone maleate  637  2,145,517  1,592,639 - 2,698,395  229  92% 
Oxycodone HCl  776  2,142,921  1,549,037 - 2,736,805  247  99% 
Nifedipine  656  2,120,320  1,450,216 - 2,790,424  249  100% 
Tamsulosin HCl  595  2,074,869  1,445,951 - 2,703,788  239  96% 
Amlodipine besylate/benazepril  637  2,001,914  1,465,679 - 2,538,148  243  98% 
Mirtazapine  746  2,001,234  1,462,548 - 2,539,921  249  100% 
Allopurinol  638  1,997,730  1,527,395 - 2,468,065  249  100% 
Rosuvastatin calcium  580  1,988,951  1,456,510 - 2,521,392  211  85% 
Bupropion HCl  704  1,987,687  1,465,122 - 2,510,253  249  100% 
Spironolactone  596  1,943,670  1,425,116 - 2,462,223  249  100% 
Fexofenadine HCl  671  1,929,230  1,312,291 - 2,546,169  249  100% 
Oxybutynin chloride  584  1,913,166  1,281,868 - 2,544,464  249  100% 
Phenytoin sodium extended  818  1,872,447  1,412,431 - 2,332,463  249  100% 
Naproxen  710  1,859,738  1,384,929 - 2,334,547  249  100% 
Tiotropium bromide  447  1,852,676  1,314,499 - 2,390,853  249  100% 
Ipratropium/albuterol sulfate  552  1,828,202  1,320,203 - 2,336,200  239  96% 
Human insulin neutral protamine 
533  1,805,084  1,326,756 - 2,283,412  249  100% 
hagedorn/regular human insulin  
Ciprofloxacin HCl  592  1,787,974  1,493,189 - 2,082,759  249  100% 
Celecoxib  517  1,776,141  1,353,725 - 2,198,557  235  94% 
Aripiprazole  770  1,773,656  1,157,694 - 2,389,618  249  100% 
Ezetimibe  518  1,765,552  1,234,755 - 2,296,349  248  100% 
Valsartan/hydrochlorothiazide  500  1,760,273  1,172,232 - 2,348,313  236  95% 
Lorazepam  593  1,733,563  1,306,363 - 2,160,763  Excluded  Excluded 
Carbamazepine  754  1,708,009  1,273,991 - 2,142,028  249  100% 
Memantine HCl  694  1,677,803  1,327,062 - 2,028,544  249  100% 
Cyclobenzaprine HCl  684  1,668,548  1,347,110 - 1,989,986  242  97% 
continued on next page 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 25  Donald M. Berwick, M.D. 
 
 
 
Table D-1:  200 Drugs Commonly Used by Dual Eligibles, continued 
Number of  Percentage of 
Sample  Projected  95-Percent Confidence 
Generic Name  Formularies  Formularies 
Size*  Drugs*  Interval*9  Including  Including 
Acetaminophen with codeine  550  1,657,322  1,276,026 - 2,038,619  249  100% 
Duloxetine HCl  551  1,646,063  1,180,919 - 2,111,207  249  100% 
Carisoprodol  619  1,641,904  1,108,632 - 2,175,176  219  88% 
Azithromycin  566  1,618,927  1,376,359 - 1,861,495  249  100% 
Benztropine mesylate  796  1,618,896  1,060,569 - 2,177,224  249  100% 
Levofloxacin  525  1,615,709  1,304,334 - 1,927,085  220  88% 
Losartan potassium  433  1,614,799  1,162,715 - 2,066,884  232  93% 
Clozapine  588  1,586,624  586,928 - 2,586,320  249  100% 
Promethazine HCl  609  1,557,329  1,197,304 - 1,917,354  235  94% 
Topiramate  563  1,536,671  503,601 - 2,569,741  249  100% 
Famotidine  511  1,531,816  1,102,603 - 1,961,030  247  99% 
Fentanyl  520  1,507,159  1,035,967 - 1,978,351  242  97% 
Meclizine HCl  430  1,476,528  1,101,060 - 1,851,997  229  92% 
Triamcinolone acetonide  490  1,470,186  1,062,870 - 1,877,501  249  100% 
Polyethylene glycol 3350  527  1,468,094  1,174,696 - 1,761,492  Excluded  Excluded 
Lisinopril/hydrochlorothiazide  425  1,465,727  1,091,460 - 1,839,993  248  100% 
Pravastatin sodium  408  1,426,419  902,937 - 1,949,901  246  99% 
Mometasone furoate  410  1,403,173  943,387 - 1,862,959  247  99% 
Glimepiride  352  1,397,945  893,743 - 1,902,147  248  100% 
Sulfamethoxazole/trimethoprim  523  1,396,698  1,176,645 - 1,616,750  249  100% 
Neutral protamine hagedorn, 
393  1,373,091  931,526 - 1,814,655  249  100% 
human insulin isophane 
Pregabalin  466  1,366,898  919,796 - 1,814,000  249  100% 
Brimonidine tartrate  388  1,320,432  873,395 - 1,767,469  249  100% 
Irbesartan  312  1,318,177  813,749 - 1,822,604  125  50% 
Amoxicillin trihydrate  454  1,309,462  1,075,245 - 1,543,678  249  100% 
Cephalexin monohydrate  507  1,307,532  1,127,307 - 1,487,756  249  100% 
Raloxifene HCl  320  1,302,736  615,860 - 1,989,613  249  100% 
Fenofibrate nanocrystallized  480  1,291,694  847,376 - 1,736,013  188  76% 
Clonazepam  546  1,263,661  929,985 - 1,597,337  Excluded  Excluded 
Estrogens, conjugated  420  1,223,449  820,507 - 1,626,390  248  100% 
continued on next page 
 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 26  Donald M. Berwick, M.D. 
 
 
 
Table D-1:  200 Drugs Commonly Used by Dual Eligibles, continued 
Number of  Percentage of 
Sample  Projected  95-Percent Confidence 
Generic Name  Formularies  Formularies 
Size*  Drugs*  Interval*9  Including  Including 
Lidocaine  383  1,209,849  884,949 - 1,534,750  249  100% 
Buspirone HCl  438  1,198,749  768,521 - 1,628,976  249  100% 
Lactulose  435  1,179,101  821,601 - 1,536,601  249  100% 
Tolterodine tartrate  417  1,169,170  820,678 - 1,517,663  218  88% 
Benazepril HCl  314  1,128,689  647,767 - 1,609,612  248  100% 
Baclofen  406  1,118,826  669,463 - 1,568,190  249  100% 
Ramipril  364  1,110,784  712,041 - 1,509,527  240  96% 
Verapamil HCl  362  1,107,285  732,129 - 1,482,440  249  100% 
Morphine sulfate  427  1,103,898  764,321 - 1,443,475  249  100% 
Ziprasidone HCl  468  1,093,177  521,471 - 1,664,884  249  100% 
Cetirizine HCl  336  1,056,576  681,238 - 1,431,914  Excluded  Excluded 
Diazepam  401  1,026,894  768,735 - 1,285,053  Excluded  Excluded 
Hydroxyzine HCl  378  1,026,368  746,962 - 1,305,775  237  95% 
Insulin regular, human  342  1,024,407  721,721 - 1,327,094  249  100% 
Carbidopa/levodopa  376  997,534  679,004 - 1,316,064  249  100% 
Isosorbide dinitrate  305  994,437  638,305 - 1,350,569  249  100% 
Latanoprost  299  970,335  675,857 - 1,264,814  224  90% 
Nystatin  364  969,703  738,140 - 1,201,266  249  100% 
Meloxicam  309  956,673  713,757 - 1,199,588  246  99% 
Propranolol HCl  354  946,417  596,114 - 1,296,721  249  100% 
Levetiracetam  370  936,163  578,489 - 1,293,838  249  100% 
Ipratropium bromide  314  922,228  597,469 - 1,246,987  249  100% 
Gemfibrozil  295  921,373  573,994 - 1,268,752  249  100% 
Ropinirole HCl  308  881,021  608,079 - 1,153,963  249  100% 
Insulin aspart  306  870,863  624,044 - 1,117,682  241  97% 
Hydralazine HCl  231  862,014  545,877 - 1,178,151  249  100% 
Lamotrigine  455  827,055  545,735 - 1,108,375  249  100% 
Temazepam  244  816,043  525,866 - 1,106,220  Excluded  Excluded 
Terazosin HCl  230  812,406  541,091 - 1,083,720  249  100% 
Colchicine  267  810,269  559,038 - 1,061,501  249  100% 
continued on next page 
 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 27  Donald M. Berwick, M.D. 
 
 
 
Table D-1:  200 Drugs Commonly Used by Dual Eligibles, continued 
Number of  Percentage of 
Sample  Projected  95-Percent Confidence 
Generic Name  Formularies  Formularies 
Size*  Drugs*  Interval*9  Including  Including 
Felodipine  235  769,722  463,439 - 1,076,005  243  98% 
Bumetanide  191  768,702  457,022 - 1,080,382  248  100% 
Amoxicillin trihydrate/potassium 
266  764,684  586,528 - 942,840  249  100% 
clavulanate 
Travoprost  229  756,219  480,776 - 1,031,661  231  93% 
Diphenoxylate HCl/atropine  221  754,080  466,449 - 1,041,710  245  98% 
Meges trol acetate  271  740,912  538,759 - 943,066  249  100% 
Diclofenac sodium  212  736,974  486,774 - 987,175  249  100% 
Losartan/hydrochlorothiazide  221  712,163  449,294 - 975,031  234  94% 
Tizanidine HCl  256  694,162  428,677 - 959,648  243  98% 
Theophylline anhydrous  140  684,833  82,581 - 1,287,085  249  100% 
Doxazosin mesylate  195  670,456  429,203 - 911,709  249  100% 
Folic acid  215  658,492  443,715 - 873,270  Excluded  Excluded 
Tramadol HCl/acetaminophen  217  649,721  397,502 - 901,940  218  88% 
Irbesartan/hydrochlorothiazide  159  643,163  328,146 - 958,181  121  49% 
Doxycycline hyclate  269  617,464  480,356 - 754,572  249  100% 
Budesonide  209  609,856  345,874 - 873,839  230  92% 
Moxifloxacin HCl  208  608,086  460,483 - 755,689  240  96% 
Dutasteride  158  605,711  313,522 - 897,900  232  93% 
Olmesartan medoxomil  179  601,304  393,023 - 809,585  171  69% 
Nabumetone  188  594,424  353,638 - 835,210  247  99% 
Eszopiclone  211  593,130  353,762 - 832,498  145  58% 
Timolol maleate  204  591,072  361,329 - 820,815  249  100% 
Methylprednisolone  181  577,634  426,689 - 728,578  249  100% 
Lithium carbonate  278  573,115  326,818 - 819,413  249  100% 
Fluconazole  208  573,017  411,820 - 734,214  249  100% 
Olopatadine HCl  214  570,664  400,211 - 741,118  226  91% 
Amiodarone HCl  147  554,006  315,652 - 792,360  249  100% 
Metolazone  162  540,187  330,312 - 750,063  247  99% 
Dicyclomine HCl  194  537,393  303,002 - 771,785  226  91% 
Fosinopril sodium  154  534,663  231,594 - 837,731  243  98% 
continued on next page 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles   Page 28  Donald M. Berwick, M.D. 
 
 
 
Table D-1:  200 Drugs Commonly Used by Dual Eligibles, continued 
Number of  Percentage of 
Sample  Projected  95-Percent Confidence 
Generic Name  Formularies  Formularies 
Size*  Drugs*  Interval* 
Including  Including 
Torsemide  165  528,402  271,876 - 784,927  244  98% 
Calcitonin, salmon, synthetic  207  527,733  256,162 - 799,304  249  100% 
Estradiol  137  522,640  325,468 - 719,811  249  100% 
Oxcarbazepine  324  520,192  330,601 - 709,783  249  100% 
Rabeprazole sodium  153  518,430  245,457 - 791,402  75  30% 
Sotalol HCl  136  517,828  219,069 - 816,586  249  100% 
Nitrofurantoin/nitrofuran macrobid  189  517,759  390,147 - 645,370  246  99% 
Omeprazole magnesium  190  516,660  300,055 - 733,265  Excluded  Excluded 
Aspirin/dipyridamole  165  516,070  290,485 - 741,656  249  100% 
Captopril  144  510,883  285,878 - 735,888  248  100% 
Metronidazole  185  510,150  366,545 - 653,756  249  100% 
Quinapril HCl  187  505,622  314,655 - 696,588  243  98% 
Fluvastatin sodium  116  504,417  259,785 - 749,049  117  47% 
Labetalol HCl  150  501,741  237,363 - 766,119  248  100% 
Hydroxyzine pamoate  232  500,012  278,759 - 721,265  222  89% 
Amylase/lipase/protease  141  490,764  231,696 - 749,832  233  94% 
Indomethacin  127  489,032  246,451 - 731,612  245  98% 
Prednisolone acetate  138  480,194  316,967 - 643,421  249  100% 
Bimatoprost  153  474,235  257,753 - 690,717  205  82% 
Finasteride  130  471,681  241,566 - 701,795  249  100% 
Hydrocortisone  170  470,577  310,651 - 630,502  249  100% 
*Sample is from the 2007 Medicare Current Beneficiary Survey.  Projections and confidence intervals are derived from its survey methodology. 
Source:  Office of Inspector General analysis of formulary inclusion of drugs commonly used by dual eligibles, 2011. 
 
OEI-05-10-00390      Part D Plans Generally Cover Drugs Commonly Used by Dual Eligibles