DEPARTMENT OF HEALTH AND HUMAN SERVICES 
OFFICE OF INSPECTOR GENERAL 
WASHINGTON, DC  20201 
JUN 30 2015 
TO: 	 Andrew M. Slavitt 
Acting Administrator 
Centers for Medicare & Medicaid Services 
FROM:  Suzanne Murrin 
Deputy Inspeetor General 
for Rwluation and Inspections 
SUBJECT: 	 Memorandum Report:  Part D Plans Generally Include Drugs Commonly 
Used by Dual Eligibles:  2015, OEI-05-15-00120 
This memorandum report fulfills the annual reporting mandate from the Patient 
Protection and Affordable Care Act (ACA) for 2015.  The ACA requires that the Office 
of Inspector General (OIG) conduct a study ofthe extent to which formularies used by 
stand-alone prescription drug plans (PDPs) and Medicare Advantage prescription drug 
plans (MA-PDs) under Medicare Part D include drugs commonly used by full-benefit 
dual-eligible individuals (i.e., individuals who are eligible for both Medicare and full 
Medicaid benefits). 1  Pursuant to the ACA, OIG must annually issue a report, with 
recommendations as appropriate.  This is the fifth report that OIG has produced to meet 
this mandate.  For the relevant text ofthe ACA, see Appendix A. 
SUMMARY 
Pursuant to the Medicare Prescription Drug, Improvement, and Modernization Act of 
2003 (MMA), comprehensive prescription drug coverage under Medicare Part Dis 
available to all Medicare beneficiaries through PD Ps and MA-PDs (hereinafter referred 
to collectively as Part D 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 dual 
eligibles enroll in Part D plans with premiums higher than the regional benchmark, they 
are responsible for paying the premium amounts above that benchmark. 
1 ACA, P.L. No. 111-148  3313(a), 42 U.S.C.  1395w-101 note. 
2 MMA, P.L. No. 108-173  101, Social Security Act,  1860D-l(a).  Page 2  Andrew M. Slavitt 
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 are allowed 
to 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 categories or classes.  CMS also assesses the utilization management tools 
present in each formulary. 
 
For this memorandum report, we determined whether the 341 unique formularies used by 
the 3,152 Part D plans operating in 2015 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.   
 
Overall, we found that the rate of Part D plan formularies inclusion of the drugs 
commonly used by dual eligibles is high, with some variation.  On average, Part D plan 
formularies include 95 percent of the commonly used drugs.  In addition, 71 percent of 
the commonly used drugs are included by all Part D plan formularies.   
 
We also found that from 2014 to 2015, the proportion of unique drugs subject to 
utilization management tools remained relatively the same.  On average, formularies 
applied utilization management tools to 29 percent of the unique drugs we reviewed in 
2015, compared to 28 percent of those we reviewed in 2014. 
 
The results of our analysis for 2015 are largely unchanged from OIGs findings in 2011, 
2012, 2013, and 2014.5,  6, 7, 8 
 
 
   
                                                 
3 A formulary is a list of drugs  covered by a Part D plan.  Part D plans can exclude drugs from their 

formularies and can control utilization for formulary-included  drugs within certain  parameters.  Social 

Security Act  1860D-4(b) and  (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 drug therapy that is the most cost-effective or 

safest and progressing if necessary to more costly or risky drug therapy. 

5 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles, OEI-05-10-00390, 

April 2011. 

6 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2012, 

OEI-05-12-00060, June 2012. 

7 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2013, 

OEI-15-13-00090, June 2013. 

8 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2014, 

OEI-05-14-00170, June 2014. 

Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 3  Andrew M. Slavitt 
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.9  Medicare beneficiaries 
generally have the option to enroll in a PDP and receive all other Medicare benefits on a 
fee-for-service basis, or to enroll in an MA-PD and receive all of their Medicare benefits, 
including prescription drug coverage, through managed care.  As of April 2015, 
approximately 39.1 million of the  53.6 million Medicare beneficiaries were enrolled in a 
Part D plan. 
 
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.10  In 2015, plan 
sponsors offer 3,152 unique Part D plans, with many plan sponsors offering multiple 
Part D plans. 
 
Dual Eligibles Under Medicare Part D 
Approximately 10.7 million Medicare beneficiaries are dual eligibles.  About 7.7 million 
dual eligibles, referred to as full-benefit dual eligibles, receive full Medicaid benefits  
and may receive assistance with premiums and cost-sharing for Medicare fee-for-service 
or Medicare managed care.11  Other dual eligibles receive only assistance with their 
Medicare premiums or cost-sharing, depending on their level of income and assets. 
 
Dual eligibles are a particularly vulnerable population.  Overall, most dual eligibles have 
very low incomes:  86 percent have annual incomes below 150 percent of the Federal 
poverty level, compared with 22 percent of all other Medicare beneficiaries.12   
Additionally, dual eligibles are in worse health than the average Medicare beneficiary:  
half are in fair or poor health, more than twice the rate of others in Medicare.13  Because 
of their self-reported health needs, dual eligibles may use more prescription drugs and 
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.14    
 
                                                 
9 MMA, P.L. No. 108-173    101, Social Security Act,  1860D-1(a). 

10 CMS, Prescription Drug Benefit Manual (PDBM), Pub. 100-18, ch. 5, Appendixes 2 and 3.  Accessed at 

http://www.cms.gov/Medicare/Prescription-Drug-Coverage/PrescriptionDrugCovContra/ 

PartDManuals.html  on April 14, 2015.  

11  Centers for Medicare & Medicaid Services, Data Tables for Medicare-Medicaid Enrollment and 

Eligibility Trends, 2013. Accessed at http://www.cms.gov/Medicare-Medicaid-Coordination/Medicare-and-
Medicaid-Coordination/Medicare-Medicaid-Coordination-Office/Analytics.html on April 22, 2015. 
 
12 Kaiser Family Foundation,  Medicares Role for Dual Eligible Beneficiaries.   Accessed at 

http://www.kff.org/medicare/upload/8138-02.pdf  on April 20, 2015. 

13 Ibid. 

14 MMA, P.L. No. 108-173    101, Social Security Act,  1860D-1(a). 

Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 4  Andrew M. Slavitt 
Medicare covers Part D plan premiums for dual eligibles up to a set benchmark.  The 
benchmark is a statutorily defined amount that is based on the average premium amounts 
for Part D plans for each region.15, 16  If dual eligibles enroll in Part D plans with 
premiums higher than the regional benchmark, they are responsible for paying the 
premium amounts above that benchmark.17    
 
Dual eligibles assignment to Part D plans.  When individuals become eligible for both 
Medicare and Medicaid, 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.18  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).19  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 PDPs 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.20  When dual eligibles change plans, their prescription drug coverage under the 
new Part D plan 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.21  CMS 
reassigns dual eligibles who were randomly assigned to their current PDPs to new PDPs 
that will have premiums at or below the regional benchmark premium.22  In addition, 
CMS notifies dual eligibles who elected their current Part D plans that their plans will 
have premiums above the regional benchmark premium.  For 2015, CMS reported 
reassigning approximately 372,000 Medicare beneficiaries, including but not exclusively 
dual eligibles, because of premium increases.  
 
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 
                                                 
15 Social Security Act,   1860D-14(b); 42 CFR   423.780(b)(2)(i). 
  
16 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. Social Security Act, 

 1860D-14(a)(3)(F). 
   
17 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.  Patient Protection and Affordable Care Act (ACA), P.L. No. 111-148 
 
 3303, Social  Security Act,   1860D-14(a)(5).  For 2014, CMS set the de minimis amount at $2 above the 

regional benchmark.  

18 CMS, PDBM, ch. 3,   40.1.4. 

19 Ibid.  

20 Ibid.,   30.3.2.  In  general, Medicare beneficiaries can switch Part D plans  only once a year during a 

defined enrollment period.  

21  Ibid.,  40.1.5. 
  
22 Ibid. 

Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 5  Andrew M. Slavitt 
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.23, 24  In addition, Part D plans must 
include Part D-covered drugs in certain categories and classes.25  
 
Part D plans may also control drug utilization by applying utilization management tools.  
These tools include requiring prior authorization to obtain drugs that are on plan 
formularies, establishing quantity limits, and requiring step therapy.  Utilization 
management tools can help Part D plans and the Part D program limit the cost of 
prescription drug coverage by placing restrictions on the use of certain drugs.   
 
In addition to these drug coverage decisions made regarding individual formularies, 
certain categories of drugs are excluded from Medicare Part D prescription drug coverage 
as mandated by the MMA.26  For example, prescription vitamins, prescription mineral 
products, and nonprescription drugs are excluded from Part D prescription drug 
coverage.27    
 
Until 2013, barbiturates and benzodiazepines were excluded from Part D prescription 
drug coverage. However, the ACA reversed this exclusion, removing these two drug 
types from the list of drug classes ineligible for Part D prescription drug coverage.28,29  
 
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.30  During this review, 
CMS analyzes 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.31  
 
                                                 
23  CMS, PDBM,  ch.  6,  30.2.1.   

24 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.  

25 Social Security Act,   1860D-4(b)(3)(G). 

26 MMA, P.L. No. 108-173    101, Social Security Act,  1860D-2(e).  

27 Social Security Act  1860D-2(e)(2), 1927(d)(2).  

28 ACA, P.L. No. 111-148  2502, Social Security Act,  1397r-8(d).  

29 CMS, Transition to  Part D Coverage of Benzodiazepines and Barbiturates Beginning in  2013. Accessed 

at http://www.cms.gov/Medicare/Prescription-Drug-Coverage/PrescriptionDrugCovContra/Downloads/ 

BenzoandBarbituratesin2013.pdf, on  April 29, 2015. 

30 CMS, PDBM,  ch.  6,  30.2.7.   

31 Ibid.  

Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 6  Andrew M. Slavitt 
CMS also assesses each formularys utilization management tools to ensure consistency 
with current industry standards and with standards that are widely used with drugs for the 
elderly and people with disabilities.32, 33, 34  
 
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.35  If their plans make negative determinations, 
beneficiaries have the right to appeal.36  If their plans deny their appeals, beneficiaries 
would need to get prescriptions from their physicians for therapeutically alternative drugs 
that are covered by their 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  
their respective Part D plans either from different Part D plans or from other prescription 
drug coverage. During Medicare beneficiaries first 90 days under a new Part D plan, the 
new plan must provide one temporary refill 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.37  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 to 
request formulary exceptions from Part D plans. 
 
Related OIG 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 drugs commonly used by 
dual eligibles under Medicaid prior to the implementation of Part D.  Approximately half 
of the 178 commonly used drugs were covered by all formularies.38  
 
In 2011, OIG issued the first annual mandated memorandum report examining dual 
eligibles access to drugs under Medicare Part D.39  In 2012, OIG issued the second 
annual mandated memorandum report examining dual eligibles access to drugs under 
                                                 
32  Ibid.,  30.2.2. 
 
33  Ibid.,  30.2.7. 
 
34 CMS looks to  appropriate guidelines from expert  organizations such as the National Committee for 

Quality Assurance, the Academy of Managed Care Pharmacy, and the National Association of Insurance 

Commissioners. 
   
35 CMS, PDBM, ch. 18,  30.1 and 30.2.  

36  Ibid.,  60.1.  

37 Ibid., ch. 6,  30.4.4.  

38 OIG,  Dual Eligibles Transition:  Part D Formularies Inclusion of  Commonly Used Drugs, 

OEI-05-06-00090, January 2006.  

39 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles, OEI-05-10-00390, 

April 2011. 

Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 7  Andrew M. Slavitt 
Medicare Part D.40  In 2013, OIG issued the third annual mandated memorandum report 
examining dual eligibles access to drug under Medicare Part D.41  In 2014, OIG issued 
the fourth annual mandated memorandum report.42  In the current memorandum report, 
we compare the results from 2014 and 2015. 
 
METHODOLOGY 
 
Scope 
As mandated in the ACA, this study assessed the extent to which drugs commonly used 
by dual eligibles are included by Part D plan formularies.  To make this assessment, we 
evaluated formularies for Part D plans operating in 2015.  As part of our assessment, we 
included dual eligibles enrollment data from April 2015, the most recent enrollment data 
available from CMS at the time of our study.  We also compared the results of our 
2015 study with those of our 2014 study.43    
 
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 latest Medicare Current Beneficiary Survey 
(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 highest utilization drugs that we identified using the MCBS, 196 are eligible for 
coverage under Part D. In this report, we refer to these 196 Part D-eligible 
high-utilization drugs as commonly used drugs. 
 
The list of 200 drugs with the highest utilization by dual eligibles referenced in this 
2015 memorandum report is similar but not identical to the list of drugs referenced in the 
2014 memorandum report.  Specifically, 185 of the 200 drugs (93 percent) listed in the 
2014 memorandum report are also listed in this 2015 memorandum report. 
 
For each study, OIG 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 and segregate 
full-benefit dual eligiblesand thus the drugs they usedfrom the total population of 
dual eligibles.   
 
We also went beyond the ACAs mandate in the 2013, 2014, and 2015 reports by 
examining the utilization management tools that Part D plan formularies apply to the 
drugs commonly used by dual eligibles.  These tools may affect dual eligibles access 
even in cases where formularies include the commonly used drugs.  Analyzing the extent 
                                                 
40 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2012, 

OEI-05-12-00060, June 2012. 

41 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2013, 

OEI-15-13-00090, June 2013.
  
42 OIG,  Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2014, 

OEI-05-14-00170, June 2014. 

43 Ibid. 

Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 8  Andrew M. Slavitt 
to which Part D plan formularies apply these 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 the 2011 MCBS Cost and Use data to create a list of the 200 drugs with 
the highest utilization by dual eligibles. The MCBS Cost and Use data contain 
information on hospitals, physicians, and prescription drug costs and utilization.  The 
2011 MCBS Cost and Use data are the most recent data available.   
 
The MCBS is a continuous, multipurpose survey that CMS conducts 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.  
In 2011, the MCBS surveyed 10,901 Medicare beneficiaries, of whom 2,149 were dual 
eligibles who had used prescription drugs during the year (out of 2,402 dual-eligible 
survey respondents). 
 
First Databank National Drug Data File. We used the April 2015 First DataBank 
National Drug Data File to identify the drug product information for the 200 drugs with 
the highest utilization by dual eligibles.  The National Drug Data File is a database that  
contains informationsuch as drug name, therapeutic category or class, and the unique 
combination of active ingredientsfor each drug as defined by a National Drug Code 
(NDC).44  
 
Part D plan data. In January 2015, we collected from CMS the formulary data and the 
plan data for Part D plans operating in 2015. The formulary data includes Part D plans 
formularies and utilization management tools for plans operating in 2015.  In 2015, there 
are 341 unique formularies offered by 3,152 Part D plans.  The plan data provides 
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.   
 
We also collected 2015 enrollment data for Part D plans.  These data provide the number 
of dual eligibles enrolled in each Part D plan as of April 2015.   
 
   
                                                 
44 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 Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 9  Andrew M. Slavitt 
Determining the Most Commonly Used Drugs 
To determine the drugs most commonly used by dual eligibles, we took the following 
steps: 
 
1. 	  We 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. The MCBS listed 155,265 drug events for 
2,149 dual eligibles who did not reside in territories.45  
 
2. 	  We 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 brand-name drug Prozac) has only one entry on our list, 
covering all strengths of both the brand-name drug Prozac and the available 
generic versions of fluoxetine hydrochloride.  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, as a given drug can have multiple NDCs.  This process 
left 155,265 drug events associated with 872 drugs.   
 
3.	   We ranked the 872 drugs by frequency of utilization, weighting the drug-event 
information from MCBS by sample weight.   
 
4.	   We selected the 200 drugs with the highest utilization by dual eligibles.  For a full 
list of the top 200 drugs, see Appendix B. 
 
5.	   We removed all drugs not covered under Part D.  Of the 200 drugs with the 
highest utilization, 196 are eligible under Part D.  Three fell into drug categories 
excluded under Part D, and one is no longer prescribed in the form taken by 
beneficiaries surveyed in the 2011 MCBS.  For details on these four drugs, see 
Appendix C. 
 
Formulary Analysis 
We analyzed the 341 unique Part D plan formularies to determine their rates of inclusion 
of the 196 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.  When a drug 
included multiple ingredients that could be dispensed separately and combined by the  
patient to the same effect as the combined drug, we treated the drug as included if the 
ingredients were included in the formulary either separately or in combination.   
 
Low rates of inclusion by formularies.  We determined which of the 196 commonly used 
drugs had low rates of inclusion by formularies by counting how many of the 
                                                 
45 For the purposes of this report, a drug event is an MCBS survey response indicating that the responding  
beneficiary took a specific drug at least  once  in 2011.   For example, one MCBS survey  respondent reported 
taking zolpidem  tartrate (Ambien) seven times in 2011.   We counted this beneficiary/drug combination as 
seven drug  events.  
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 10  Andrew M. Slavitt 
341 formularies covered each drug.  We considered a drug to have a low rate of inclusion 
if it was included by 75 percent or less of formularies.  For such drugs, we counted the 
number of drugs (if any) that each formulary covered in the same therapeutic category or 
class. 
 
We conducted this analysis to ensure that dual eligibles have access to therapeutically 
similar drugs.  We also conducted additional research to identify potential reasons why  
some of the 196 commonly used drugs were included by 75 percent or less of 
formularies. 
 
Utilization management tools. We determined the extent  to which Part D plans apply 
utilization management tools to the 196 drugs that we reviewed.  The tools that we 
reviewed are prior authorization, quantity limits, and step therapy. 
 
To determine the extent to which the 196 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 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 196 commonly used drugs that are on each Part D formulary.  We then 
calculated the percentage of unique drugs to which each Part D plan formulary applies 
utilization management tools.  
 
Enrollment Analysis  
We weighted the formulary analysis by dual-eligible enrollment and weighted the 
analysis of utilization management tools by both dual-eligible enrollment and Medicare 
enrollment.  To do this, we applied enrollment data from April 2015 to Part D plans 
available in 2015. 
 
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, 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 2011 account for 88 percent of all prescriptions dispensed 
to the dual-eligible respondents in the 2011 MCBS.    
 
Because the lists of commonly used drugs in the 2014 and 2015 memorandum reports are 
not identical, the changes in rates of inclusion by formularies and in application of 
utilization management tools between 2014 and 2015 may reflect changes as to which 
specific drugs were included in the lists, rather than changes regarding any specific drug.  
However, the two lists largely overlap; 93 percent of the drugs on the list in our 
2014 report were also on the list in this 2015 memorandum report. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 11  Andrew M. Slavitt 
 
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 86 and 100 Percent of the Drugs 
Commonly Used by Dual Eligibles  
On average, Part D plan formularies include 95 percent of the drugs commonly used by 
dual eligibles. Of the 341 unique formularies used by Part D plans in 2015, 
12 formularies include 100 percent of the commonly used drugs.  At the other end of the 
inclusion range, one formulary includes 86 percent of the commonly used drugs.  CMS 
generally requires Part D plan formularies to include at least two drugsrather than all 
drugsin each therapeutic category or class.  Therefore, Part D plan formularies may 
still meet CMSs formulary requirements even if they do not include all of the drugs we 
identified as commonly used by dual eligibles. 
 
Part D plan formularies rate of inclusion of the drugs commonly used by dual eligibles 
in 2015 is nearly identical to that of 2014.  The average rate of inclusion decreased 
slightly between 2014 and 2015, from 96 percent to 95 percent.  The range of inclusion 
rates was the same in 2015 as in 2014from 86 to 100 percent of the drugs. 
 
Nationally, PDP and MA-PD formularies have similar rates of inclusion of the drugs 
commonly used by dual eligibles, averaging 94 percent and 95 percent, respectively.  For 
PDP formularies, the rates of inclusion ranged from 88 to 100 percent; for MA-PD 
formularies, they ranged from 86 to 100 percent.  Eighteen formularies5 percent of the 
341 unique formularies used by Part D plans in 2015are offered by both PDPs and 
MA-PDs. 
 
Regionally, all dual eligibles 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 98 percent of the commonly used drugs, and every MA-PD region has a plan that 
includes at least 98 percent of these drugs.  Appendix D provides a breakdown of 
formularies rates of inclusion of the drugs 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 percentage 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, 
such plans. For drugs commonly used by dual eligibles, formularies for such plans have 
rates of inclusion that range from 88 percent to 100 percent.  Approximately 86 percent 
of dual eligibles are enrolled in Part D plans with premiums below the regional 
benchmark. 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 12  Andrew M. Slavitt 
Ninety-four 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 
9.7 million dual eligibles enrolled in Part D plans, 94 percent are enrolled in Part D plans 
that use formularies that include at least 90 percent of the commonly used drugs.  Only 
6 percent of dual eligibles are enrolled in Part D plans that use formularies that include 
less than 90 percent of these 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  
Part D Plans With Formularies That  Number of Dual   Percentage of Dual 
Include:   Eligibles Enrolled*  Eligibles Enrolled  
100% of commonly  used drugs   159,954   2%  
95% to 99% of commonly used drugs  2,209,253   23%  
90% to 94% of commonly used drugs  6,866,185   70%  
85% to 89% of commonly used drugs  548,415   6% 
     Total   9,783,807   100%**  
 
Source:  OIG analysis of  formulary inclusion of drugs commonly used by dual eligibles and dual  eligibles 

enrollment, 2015. 

*Rounded to  the nearest 1,000. 

**Percentages do not add to 100 percent because of rounding. 

 
The percentage of dual eligibles enrolled in Part D plans that include at least 90 percent 
of the drugs commonly used by dual eligibles decreased from 99 percent in 2014 to 
94 percent in 2015.    
 
Sixty-Six 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 that  regardless of the Part D plan in which they 
are enrolled, the plans formulary will include many of these drugs.  By drug, formulary 
inclusion ranges from 33 percent to 100 percent.  At one end of the range, there is 
a commonly used drug that is included in 33 percent of Part D plan formularies, and at 
the other end, 130 drugs are included in all plan formularies.  The average rate of 
inclusion by formularies is 95 percent.  Table 2 provides a summary of rates of inclusion 
by formularies.  Appendix B lists the commonly used drugs and their respective rates of  
inclusion by formularies. 
 
   
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 13  Andrew M. Slavitt 
Table 2: Formularies Rates of Inclusion of Commonly Used Drugs  
Percentage of the 196 Commonly  
Percentage of the 341 Formularies  Used Drugs Included in 
Formularies  
66%  
100%  
(130 drugs)  
21%  
85% to 99%  
(42 drugs)  
7%  
76% to 84%  
(13 drugs)  
6%  
33% to 75%  
(11 drugs) 
100%  
 Total  
(196 drugs)  
Source:  OIG analysis of  formulary inclusion of drugs commonly used by dual eligibles, 2015. 
 
The rates of formulary inclusion of the drugs commonly used by dual eligibles in 2015 
are similar to those in 2014.  The percentage of commonly used drugs included in all 
formularies  increased slightly between 2014 and 2015, from 64 percent to 66 percent. 
 
Part D plan formularies include certain drugs less frequently than others. Of the 
commonly used drugs, 6 percent (11 drugs) are included by 75 percent or less of Part D 
plan formularies.  Table 3 provides the percentage of formularies covering each of these 
11 drugs. 
 
The drugs that make up this group include both brand-name and generic drugs, and are 
used to treat a variety of primary indications.  Six of the eleven drugs are brand-name  
drugs, which are typically more costly than generic drugs.  As for the primary 
indications, 3 of the 11 drugs are used for diabetic therapy, 2 of the 11 drugs are muscle 
relaxants, and the remaining drugs treat a variety of conditions including overactive 
bladder, high cholesterol, anxiety, and hypertension. 
 
Table 3: Drugs Included by 75 Percent or Less of Part D Plan Formularies  
Rate of  
Generic Name of Drug   Primary Indication(s)   Inclusion by  
Formularies  
Insulin lispro   Diabetes   75%  
Valsartan*  Hypertension (high blood pressure)   67%  
Glyburide/metformin HCl  Diabetes  62%  
Glyburide  Diabetes  61%  
Conjugated estrogen/medroxyprogesterone 
Menopause  59%  
acet  
Ezetimibe/simvastatin*  Hyperlipidemia (high cholesterol)  57%  
Methocarbamol*  Musculoskeletal pain  55%  
Dyspepsia, peptic ulcer disease, gastroesophageal reflux 
Esomeprazole magnesium*   49%  
disease, Zollinger-Ellison syndrome  
Hydroxyzine pamoate*   Anxiety   46%  
Carisoprodol*   Musculoskeletal pain   42%  
Darifenacin hydrobromide*   Overactive bladder   33%  
Source:  OIG analysis of  formulary inclusion of drugs commonly used by dual eligibles, 2015. 
* These drugs also  had low formulary inclusion rates in 2014.  
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 14  Andrew M. Slavitt 
Although Part D formularies frequently omit these 11 drugs, they all cover other drugs in 
the same therapeutic classes.  For these 11 drugs, 100 percent of formularies cover at 
least 1 drug in the same therapeutic class that is also on the list of 196 drugs commonly 
used by dual eligibles. 
  
The number of drugs included by 75 percent or less of formularies  stayed the same 
11 drugsin 2014 and 2015. There are seven  drugs with low inclusion rates in 2015 that 
were also on the list of commonly used drugs with low inclusion rates in our 2014 report; 
these drugs are noted in Table 3. Five of these seven drugs were also on the list of drugs 
with low inclusion rates in our 2013 report.  
 
There are many potential reasons why a commonly used drug might be included by 
75 percent or less of formularies: 
 
   Four of these drugsmethocarbamol, carisoprodol, conjugated estrogen/ 
medroxyprogesterone, and hydroxyzine pamoateare on CMSs list of Part D 
medications that are high-risk for the elderly.46     
   Further, seven of these drugscarisoprodol, darifenacin hydrobromide, 
hydroxyzine pamoate, methocarbamol, glyburide, glyburide/metformin HCl, and 
estrogensare listed by the American Geriatrics Society as being potentially 
inappropriate for older adults.47  
 
Low rates of inclusion by formularies may require dual eligibles to obtain a nonformulary 
drug. 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.48  Finally, dual eligibles may switch to Part D 
plans that include their drugs, with the new coverage becoming effective the following 
month.49  
 
                                                 
46 This listUse of High-Risk Medications in the Elderly:   High-Risk Medications is part of the 
 
Healthcare Effectiveness and  Information Set national  drug code  measures published by  the National 
 
Committee for Quality Assurance.  A drug that is listed as being  high  risk for the elderly is one that has a 

high  risk of serious side effects in that population.  CMS uses this medication list to calculate the 

percentage of Medicare beneficiaries who received at least one high-risk medication in the past year.  CMS 

publishes this  percentage and other measures of Part D  patient safety so that Medicare beneficiaries can 

make informed  decision  in  choosing a Part D plan for their prescription drug  coverage.  National 
 
Committee on  Quality Assurance, HEDIS 2012 NDC List.  Accessed at 

http://www.cms.gov/Medicare/Prescription-Drug-Coverage/PrescriptionDrugCovContra/Downloads/ 

MemoPatientSafetyMeasures_071610.pdf on April 15, 2015. 

47 The American Geriatrics Society, American  Geriatrics Society Updated  Beers Criteria for Potentially 

Inappropriate Medication Use in Older  Adults, 2012. 

48 CMS, PDBM, ch. 18,  30.2.2. 
 
49 Ibid., ch. 3,  30.3.2. 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 15  Andrew M. Slavitt 
The Percentage of Commonly Used Drugs Subject to Utilization Management Tools 
by Plan Formularies Increased Slightly Between 2014 and 2015 
For the unique drugs that compose the list of commonly used drugs, the percentage 
subject to utilization management tools by Part D plan formularies increased slightly  
from an average of 28 percent in 2014 to an average of 29 percent in 2015.  Formularies 
for plans with premiums below and those with premiums above the regional benchmarks 
had a similar percentage of drugs27 percent and 29 percent, respectivelythat were 
subject to utilization management tools.  See Table 4 for a breakdown of the percentage 
of unique drugs to which Part D plan formularies apply utilization management tools in 
2014 and 2015. 
 
Table 4: Part D Plan Formularies Application of Utilization Management Tools to 
Commonly  Used Drugs, 2014 and 2015  
Percentage of Unique Drugs   Number of   Percentage of   Number of  
Percentage of  
to Which Utilization  2014 Part D  2014 Part D  2015 Part D 
2015 Part D Plan  
Management Tools Are  Plan  Plan  Plan 
Formularies  
Applied  Formularies   Formularies   Formularies  
Greater than 40%   30  9%   49  14%  
30% to 39%   136  41%   137  40%  
20% to 29%   65  20%   66  19%  
10% to 19%   75  23%   65  19%  
Less than 10%   23  7%   24  7% 
     Totals   329  100%   341  100%*  
Source:  OIG analysis of  formulary inclusion of drugs commonly used by dual eligibles, 2015. 
* Percentages do not add to 100 percent because of rounding. 
 
The percentage of drugs subject to quantity limits or prior authorization increased slightly 
from 2014 to 2015, while the percentage of drugs subject to step therapy remained the 
same.  Formularies use of quantity limits and use of prior authorization each increased  
by 1 percentfrom 24 to 25 percent and from 3 to 4 percent of unique drugs, 
respectively. The percentage of unique drugs for which formularies required step therapy 
was 2 percent in both 2014 and 2015. 
 
The rate at which plan formularies apply specific utilization management tools varies 
widely.  In 2015, some formularies applied utilization management tools to none of the 
unique drugs, whereas at the other end of the range, some applied tools to 47 percent of 
the unique drugs. More specifically, formularies apply quantity limits to between 0 and 
43 percent of unique drugs, require prior authorization for between 0 and 10 percent, and 
require step therapy for between 0 and 15 percent.   
 
Looking at enrollment across plans provides a slightly different picture than looking only 
at plans themselves.  On average, plan formularies in 2015 apply utilization management 
tools to 29 percent of unique drugs. However, dual eligibles tend to be enrolled in plans 
with formularies that apply these tools at a slightly higher rate.  In 2015, the median plan 
weighted by dual-eligible enrollment applies such tools to 35 percent of unique drugs; in 
2014, the figure was 34 percent. Similarly, the median plan weighted by overall 
Medicare enrollment applies these tools to 34 percent of unique drugs in 2015; in 2014, 
the figure was 33 percent.   
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 16  Andrew M. Slavitt 
Both dual eligibles and Medicare beneficiaries overall tend to be enrolled in plans with 
formularies that apply utilization management tools to between 30 and 47 percent of 
unique drugs. In 2015, 63 percent of dual eligibles and 57 percent of Medicare 
beneficiaries overall were enrolled in plans with formularies in this range.  Table 5 shows 
enrollment in Part D plans by dual eligibles and Mediciare beneficiaries, as broken down 
by the percentages at which the plans formularies apply utilization management tools.   
 
Table 5: Beneficiary Enrollment in Part D Plans by Application of Utilization 

Management Tools to Commonly Used Drugs, 2014 and 2015  

Percentage of   Percentage of  
Percentage of Unique Drugs to   Percentage of   Percentage of  
Medicare  Medicare 
Which Plan Formularies Apply   Dual Eligibles  Dual Eligibles 
Beneficiaries  Beneficiaries 
Utilization Management Tools   Enrolled, 2014   Enrolled, 2015  
Enrolled, 2014   Enrolled, 2015  
Greater than 40%   5%   14%   8%   16%  
30% to 39%   63%   44%   54%   41%  
20% to 29%   7%   6%   32%   34%  
10% to 19%   24%   32%   4%   5%  
Less than 10%   2%   4%   2%   3% 
     Totals   100%*   100%   100%   100%*  
Source:  OIG analysis of dual-eligible enrollment and Medicaid  beneficiary enrollment by rates of utilization management tool 
 
application to drugs commonly used by dual eligibles, 2015. 

*Percentages do not add to 100 percent because of rounding. 
 
 
Further, although utilization management tools control access to drugs, they are 
important tools for managing costs in Medicare and ensuring appropriate utilization of  
drugs. For example, oxycodone HCl/acetaminophen drugs saw more than a 30-percent 
increase in formulary application of utilization management controls in 2013.  Such 
limits may be intended to ensure appropriate utilization, as CMSs Part D 2013 guidance 
to Part D sponsors set forth expectations for reviews of opioid overutilization to help 
ensure that opioids are prescribed and used correctly.50  
 
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.  By law, 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 11 drugs that this memorandum report identifies as 
being included by 75 percent or less 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 
                                                 
50 CMS, Supplemental Guidance Related to  Improving Drug Utilization Review Controls in  Part D.  
Accessed at https://www.cms.gov/Medicare/Prescription-Drug-Coverage/PrescriptionDrugCovContra/  
Downloads/HPMSSupplementalGuidanceRelated-toImprovingDURcontrols.pdf on April 29, 2015. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 17  Andrew M. Slavitt 
95 percent of the commonly used drugs. Part D plan formularies inclusion of the 
commonly used drugs ranges from 86 percent to 100 percent.  Formulary inclusion rates 
are similar for PDPs and MA-PDs.  Further, formularies for Part D plans with premiums  
below the regional benchmark include the commonly used drugs at a rate similar to that 
of Part D plan formularies overall. 
 
Inclusion rates for the 196 drugs commonly used by dual eligibles are largely unchanged 
compared with those from OIGs 2014 memorandum report.  Part D plan formularies 
include roughly the same percentage of these commonly used drugs in 2015 as they did 
in 2014. Enrollment in plans that cover at least 90 percent of unique drugs decreased 
slightly, with 94 percent of dual eligibles enrolled in such plans in 2015 compared to 
99 percent in 2014. 
 
Because some variation exists 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 use alternative methods to access the drugs they take.  They 
could appeal prescription drug coverage decisions, switch prescription drugs, or switch 
Part D plans. These scenarios require additional effort by dual eligibles and may result in 
administrative barriers to accessing certain prescription drugs. 
 
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 memorandum report is being issued directly in final form because it contains no 
recommendations.  We have included the list of the 200 drugs with the highest utilization 
by dual eligibles. If you have comments or questions about this memorandum report, 
please provide them within 60 days.  Please refer to report number OEI-05-15-00120 in 
all correspondence.  
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 18  Andrew M. Slavitt 
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. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 19  Andrew M. Slavitt 
APPENDIX B  
 
Commonly Used Drugs and Rates of Inclusion by Formularies 
 
Table B-1: 200 Drugs With the Highest Utilization by Dual Eligibles   
Number of   Percentage of  
Sample  Projected   95-Percent Confidence 
Generic Name   Formularies  Formularies 
Size*  Drugs*   Interval*  
Including   Including  
Simvastatin  3,900   17,347,406   15,514,36719,180,445   340  100%  
Lisinopril  3,853   17,267,881   15,114,37819,421,384   341  100%  
Hydrocodone/acetaminophen  4,632   16,947,722   15,258,69718,636,747   341  100%  
Omeprazole  4,014   15,672,875   14,093,41717,252,333   341  100%  
Levothyroxine sodium  3,476   14,830,579   13,126,54216,534,615   341  100%  
Furosemide  3,428   14,434,347   12,915,25015,953,443   341  100%  
Amlodipine besylate  2,919   13,077,400   11,368,25014,786,550   341  100%  
Metformin HCl   2,865   12,804,478   11,154,96014,453,996   341  100%  
Potassium chloride  2,745   10,583,238   9,213,26811,953,209   341  100%  
Metoprolol tartrate   2,352   9,997,980   8,527,26511,468,696   341  100%  
Gabapentin  1,856   7,678,814   6,546,9458,810,682  341  100%  
Warfarin sodium   1,969   7,669,750   6,220,2579,119,244  341  100%  
Atorvastatin calcium  1,658   7,345,895   6,149,4468,542,344  341  100%  
Hydrochlorothiazide  1,557   6,986,485   5,967,2178,005,753  341  100%  
Clopidogrel bisulfate  1,544   6,943,517   5,750,5628,136,471  341  100%  
Albuterol sulfate  1,594   6,785,246   5,751,6497,818,843  341  100%  
Esomeprazole magnesium  1,409   6,620,580   5,333,1707,907,989  167  49%  
Citalopram hydrobromide   1,680   6,426,818   5,291,1027,562,533  341  100%  
Atenolol  1,308   6,334,483   5,181,3297,487,637  341  100%  
Tramadol HCl  1,443   5,544,220   4,444,0846,644,356  341  100%  
Zolpidem tartrate   1,310   5,454,634   4,429,9326,479,336  328  96%  
Carvedilol  1,236   5,320,616   4,330,4626,310,771  341  100%  
Ranitidine HCl  1,381   5,134,725   3,948,4796,320,972  341  100%  
Valsartan  1,074   4,944,768   3,960,1825,929,353  228  67%  
Trazodone HCl   1,289   4,925,948   3,836,0526,015,844  341  100%  
Oxycodone  1,346  4,865,501   3,572,6116,158,391  341  100%  
HCl/acetaminophen 
Glipizide  1,118   4,768,378   3,897,3295,639,428  341  100%  
Sertraline HCl   1,186   4,657,331   3,757,0535,557,609  341  100%  
Fluticasone/salmeterol  1,037   4,647,993   3,735,9885,559,997  304  89%  
Metoprolol succinate  874  4,576,199   3,687,3115,465,088  340  100%  
Insulin glargine,hum.rec.anlog   1,057   4,519,573   3,638,0965,401,051  329  96%  
Alendronate sodium  1,098   4,517,069   3,714,3125,319,827  341  100%  
Risperidone  1,337   4,321,416   3,370,7555,272,076  341  100%  
Quetiapine fumarate  1,486   4,139,968   3,230,7485,049,188  341  100%  
continued on next page 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 20  Andrew M. Slavitt 
Table B-1: 200 Drugs With the Highest Utilization by Dual Eligibles, continued  
Number of   Percentage of  
Sample  Projected   95-Percent Confidence 
Generic Name   Formularies  Formularies 
Size*  Drugs*   Interval*  
Including   Including  
Prednisone  1,043   4,060,613   3,342,7864,778,439  341  100%  
Fluticasone propionate   967  3,994,341   3,322,8454,665,836  341  100%  
Rosuvastatin calcium   749  3,946,728   3,150,3224,743,134  279  82%  
Pravastatin sodium  792  3,669,913   2,920,6884,419,137  341  100%  
Donepezil HCl  1,100   3,629,564   2,875,1414,383,988  341  100%  
Isosorbide mononitrate   748  3,561,729   2,815,3234,308,136  341  100%  
Cyclobenzaprine HCl  802  3,507,572   2,743,8744,271,270  340  100%  
Montelukast sodium  845  3,433,580   2,539,8374,327,323  341  100%  
Pioglitazone HCl  740  3,315,739   2,511,9444,119,534  341  100%  
Diltiazem HCl  791  3,236,508   2,409,3494,063,667  341  100%  
Clonidine HCl  785  3,207,052   2,329,8314,084,273  341  100%  
Lovastatin  655  3,180,423   2,491,7923,869,054  338  99%  
Divalproex sodium   1,080   3,083,963   2,353,0573,814,868  341  100%  
Meloxicam  715  3,045,674   2,442,2473,649,102  340  100%  
Famotidine  716  3,002,313   2,222,2603,782,365  340  100%  
Allopurinol  721  2,959,137   2,201,7493,716,525  341  100%  
Ibuprofen  828  2,920,144   2,333,8923,506,396  341  100%  
Escitalopram oxalate  858  2,894,303   2,278,1193,510,486  340  100%  
Losartan potassium  587  2,883,618   2,142,5893,624,648  341  100%  
Bupropion HCl   689  2,871,472   2,059,5623,683,383  341  100%  
Amitriptyline HCl  666  2,871,130   1,827,9693,914,291  341  100%  
Glimepiride  632  2,851,481   2,001,2283,701,734  341  100%  
Lisinopril/hydrochlorothiazide  563  2,838,412   2,174,9633,501,861  341  100%  
Pantoprazole sodium  620  2,784,126   2,004,9503,563,302  340  100%  
Tiotropium bromide  593  2,775,253   2,119,6463,430,860  332  97%  
Tamsulosin HCl  670  2,757,815   2,144,2143,371,415  341  100%  
Azithromycin  723  2,640,943   2,265,6203,016,265  341  100%  
Oxycodone HCl   773  2,593,236   1,865,6883,320,784  341  100%  
Paroxetine HCl   692  2,592,058   1,793,1773,390,938  341  100%  
Duloxetine HCl  664  2,529,408   1,768,4413,290,374  341  100%  
Aripiprazole  784  2,509,941   1,849,3213,170,561  341  100%  
Alprazolam  722  2,507,449   1,908,2503,106,648  313  92%  
Celecoxib  549  2,487,716   1,753,3023,222,130  272  80%  
Enalapril maleate  628  2,486,122   1,773,4483,198,796  341  100%  
Triamterene/hydrochlorothiazide  489  2,472,394   1,698,3983,246,390  341  100%  
Fluoxetine HCl  671  2,442,283   1,858,8773,025,689  341  100%  
Lansoprazole  520  2,432,783   1,664,3263,201,239  272  80%  
continued on next page 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 21  Andrew M. Slavitt 
Table B-1: 200 Drugs With the Highest Utilization by Dual Eligibles, continued  
Number of   Percentage of  
Sample  Projected   95-Percent Confidence 
Generic Name   Formularies  Formularies 
Size*  Drugs*   Interval*  
Including   Including  
Memantine HCl   676  2,342,026   1,726,8102,957,242  341  100%  
Clonazepam  646  2,266,382   1,667,3342,865,431  341  100%  
Fexofenadine HCl  516  2,230,968   1,530,3942,931,543     
Benztropine mesylate   805  2,226,864   1,615,8822,837,845  340  100%  
Ezetimibe  418  2,160,362   1,594,7282,725,996  339  99%  
Naproxen  557  2,141,422   1,665,5112,617,333  341  100%  
Carisoprodol  504  2,069,351   1,346,3672,792,335  144  42%  
Spironolactone  481  2,061,652   1,505,8272,617,477  341  100%  
Sulfamethoxazole/  636  2,057,059   1,708,1142,406,003  341  100%  
trimethoprim  
Diclofenac sodium   477  2,044,525   1,547,1622,541,887  341  100%  
Valsartan/  430  2,030,978   1,418,5452,643,412  331  97%  
hydrochlorothiazide 
Ciprofloxacin HCl  608  2,001,235   1,755,9472,246,522  341  100%  
Topiramate  720  1,991,977   1,240,1952,743,760  341  100%  
Mirtazapine  641  1,962,056   1,543,9192,380,194  341  100%  
Carbamazepine  595  1,924,763   1,352,4542,497,073  341  100%  
Promethazine HCl  527  1,911,351   1,452,2292,370,473  293  86%  
Meclizine HCl  399  1,906,646   1,148,1542,665,138  341  100%  
Cephalexin  511  1,899,305   1,508,9582,289,651  341  100%  
Fenofibrate nanocrystallized   413  1,898,960   1,336,9842,460,935  315  92% 
Ipratropium/albuterol sulfate  463  1,888,932   1,347,4002,430,464  333  98%  
Venlafaxine HCl   627  1,861,582   1,234,5592,488,604  341  100%  
Oxybutynin chloride  568  1,849,363   1,498,6052,200,122  341  100%  
Morphine sulfate   491  1,845,759   1,195,1572,496,362  341  100%  
Digoxin  515  1,845,656   1,427,8002,263,512  341  100%  
Olanzapine  627  1,790,633   1,160,0052,421,261  341  100%  
Lorazepam  540  1,786,878   1,296,0972,277,659  341  100%  
Verapamil HCl  387  1,786,033   1,240,4162,331,649  341  100%  
Levetiracetam  543  1,782,579   1,162,3632,402,794  341  100%  
Nitroglycerin  436  1,738,085   1,318,0752,158,095  341  100%  
Propranolol HCl   420  1,722,294   989,5182,455,070  341  100%  
Pramipexole di-HCl  340  1,721,576   526,5392,916,613  341  100%  
Pregabalin  498  1,699,388   1,279,7652,119,011  341  100%  
Glyburide  357  1,698,601   1,266,4042,130,799  207  61%  
Travoprost  378  1,669,219   1,101,4402,236,998  300  88%  
Nifedipine  409  1,664,761   1,178,3452,151,176  329  96%  
Insulin aspart  452  1,659,889   1,219,1212,100,657  276  81%  
continued on next page 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 22  Andrew M. Slavitt 
Table B-1: 200 Drugs With the Highest Utilization by Dual Eligibles, continued  
Number of   Percentage of  
Sample  Projected   95-Percent Confidence 
Generic Name   Formularies  Formularies 
Size*  Drugs*   Interval*  
Including   Including  
Lidocaine  432  1,643,259   1,137,8192,148,699  341  100%  
Phenytoin sodium extended   514  1,576,690   1,162,2491,991,130  341  100%  
Polyethylene glycol 3350  471  1,567,563   1,246,9091,888,216  341  100%  
Buspirone HCl   395  1,563,876   1,033,8932,093,859  341  100%  
Hydroxyzine HCl   432  1,563,435   1,170,9251,955,945  266  78%  
Baclofen  457  1,536,847   996,2842,077,411  341  100%  
Hydralazine HCl  369  1,460,232   1,067,9081,852,555  341  100%  
Sitagliptin phosphate  308  1,451,576   857,4592,045,694  326  96%  
Ipratropium bromide  283  1,406,253   766,0352,046,471  341  100%  
Benazepril HCl  269  1,401,998   938,2981,865,698  340  100%  
Fentanyl  420  1,388,578   870,9241,906,232  341  100%  
Latanoprost  360  1,377,318   1,061,9231,692,713  341  100%  
Amoxicillin  384  1,369,672   1,162,5731,576,772  341  100% 
Lamotrigine  522  1,343,506   915,1241,771,888  341  100%  
Insulin regular, human   387  1,330,468   885,1071,775,828  341  100%  
Doxazosin mesylate  322  1,326,945   924,4071,729,482  341  100%  
Acetaminophen with codeine   358  1,306,922   931,4751,682,370  341  100%  
Levofloxacin  338  1,289,250   1,014,1651,564,336  341  100%  
Gemfibrozil  322  1,271,415   854,0411,688,788  341  100%  
Ropinirole HCl   306  1,239,322   736,0451,742,599  341  100%  
Tizanidine HCl  416  1,235,871   775,5681,696,175  341  100%  
Ezetimibe/simvastatin  258  1,190,684   703,0851,678,284  195  57%  
Dicyclomine HCl   290  1,188,897   669,7921,708,001  339  99%  
Nph, human insulin isophane  228  1,176,930   617,1961,736,663  341  100%  
Losartan/hydrochlorothiazide  263  1,176,050   755,8141,596,286  341  100%  
Metoclopramide HCl  296  1,167,293   728,9711,605,615  341  100%  
Methocarbamol  297  1,140,023   818,3321,461,714  187  55%  
Finasteride  197  1,134,898   652,0931,617,704  341  100%  
Lactulose  323  1,134,620   627,9551,641,286  341  100%  
Tolterodine tartrate  272  1,129,540   738,6961,520,385  320  94%  
Carbidopa/levodopa  345  1,121,177   715,8691,526,485  341  100%  
Bimatoprost  206  1,094,783   676,4491,513,117  298  87%  
Budesonide/formoterol  240  1,086,250   644,0631,528,437  285  84%  
fumarate  
Nystatin  330  1,084,400   818,3381,350,463  341  100%  
Doxycycline hyclate  361  1,082,007   834,3131,329,702  341  100%  
Methadone HCl  230  1,080,920   418,1881,743,653  337  99%  
Triamcinolone acetonide  327  1,076,999   882,9201,271,077  341  100%  
Glyburide/metformin HCl  205  1,063,514   723,1571,403,871  210  62%  
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 23  Andrew M. Slavitt 
continued on next page 
Table B-1: 200 Drugs With the Highest Utilization by Dual Eligibles, continued  
Number of   Percentage of  
Sample  Projected   95-Percent Confidence 
Generic Name   Formularies  Formularies 
Size*  Drugs*   Interval*  
Including   Including  
Ramipril  187  1,036,844   646,8391,426,849  339  99%  
Brimonidine tartrate  233  1,003,480   659,8031,347,156  341  100%  
Omega-3 acid ethyl esters   224  999,736   606,3701,393,102  339  99%  
Estrogens, conjugated   208  984,811   642,3021,327,320  324  95%  
Mometasone furoate  247  972,134   684,5191,259,748  340  100%  
Amlodipine  228  959,920   603,0841,316,756  325  95%  
besylate/benazepril 
Niacin  284  950,310   593,9581,306,662  338  99%  
Folic acid   234  917,230   579,8141,254,647     
Diazepam  242  914,849   602,0561,227,643  341  100%  
Risedronate sodium  177  909,354   496,5061,322,202  262  77%  
Solifenacin succinate  212  905,807   544,6301,266,985  261  77%  
Hum insulin nph/reg insulin  277  891,664   585,9371,197,392  341  100%  
hm 
Insulin lispro  204  886,766   488,8871,284,646  255  75%  
Fluconazole  244  876,604   629,7921,123,416  341  100%  
Megestrol acetate  190  860,802   550,5661,171,039  341  100%  
Olopatadine HCl  233  856,208   531,9291,180,487  297  87%  
Amoxicillin/potassium clav   249  842,524   675,7981,009,249  341  100% 
Ergocalciferol (vitamin D)  246  840,670   572,7951,108,546     
2
Metolazone  175  821,115   473,1091,169,121  337  99%  
Ibandronate sodium  180  811,781   469,3711,154,191  319  94%  
Clozapine  258  810,313   187,5551,433,071  341  100%  
Insulin detemir  219  791,709   502,6591,080,758  289  85%  
Timolol maleate  171  791,425   446,9361,135,915  341  100%  
Fenofibrate  217  789,433   472,6151,106,252  340  100%  
Estradiol  139  779,861   406,7401,152,981  341  100%  
Quinapril HCl   166  767,100   405,5561,128,644  338  99%  
Dutasteride  144  766,689   374,9661,158,412  306  90%  
Nitrofurantoin monohyd/   211  754,425   528,967979,883  326  96%  
m-cryst  
Terazosin HCl   182  749,047   398,5901,099,504  341  100%  
Calcitriol  174  742,544   394,3871,090,700  341  100%  
Amiodarone HCl  159  726,161   428,0491,024,273  341  100%  
Fenofibric acid (choline)  183  697,843   242,1361,153,549  274  80%  
Temazepam  183  696,803   364,5611,029,045  259  76%  
Olmesartan medoxomil  133  691,273   352,0241,030,523  269  79%  
Cinacalcet HCl  204  689,875   378,3151,001,435  341  100%  
Ziprasidone HCl   335  685,268   386,358984,178  341  100%  
continued on next page 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 24  Andrew M. Slavitt 
Table B-1: 200 Drugs With the Highest Utilization by Dual Eligibles, continued  
Number of   Percentage of  
Sample  Projected   95-Percent Confidence 
Generic Name   Formularies  Formularies 
Size*  Drugs*   Interval*  
Including   Including  
Estrogen,con/m-progest acet   89  680,598   163,7531,197,443  201  59%  
Hydroxyzine pamoate   176  673,614   299,9161,047,312  155  45%  
Prednisolone acetate   148  647,730   466,124829,336  301  88%  
Clotrimazole/betamethasone  170  645,039   374,168915,909  284  83%  
dip 
Darifenacin hydrobromide   167  643,527   364,924922,130  113  33%  
Hydrocortisone  152  613,981   360,669867,293  341  100%  
Ketoconazole  175  609,470   407,703811,237  341  100%  
Mycophenolate mofetil  184  603,446   282,168924,724  341  100%  
Hydroxychloroquine sulfate  112  602,009   406,799797,218  341  100%  
Haloperidol  261  594,843   343,034846,652  341  100%  
Sevelamer carbonate  157  592,190   348,152836,228  316  93%  
Cyclosporine  157  589,434   314,216864,653  341  100%  
Isosorbide dinitrate  121  578,099   267,561888,636  341  100%  
Doxepin HCl  169  578,028   275,021881,036  341  100%  
Bumetanide  115  574,123   220,061928,186  341  100%  
Mupirocin  166  559,222   377,854740,591  341  100%  
Labetalol HCl  146  559,195   303,504814,886  341  100%  
Albuterol  131  553,548   388,411718,684     
Theophylline anhydrous  137  552,738   232,889872,588  341  100% 
Source:  OIG analysis of drugs commonly used by dual eligibles, 2015. 

*Sample is from the 2011 MCBS.  Projections and  confidence intervals are derived from its survey methodology. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 25  Andrew M. Slavitt 
APPENDIX C 
 
Four Drugs Commonly Used by Dual Eligibles and Not Covered Under Part D  
 
Generic Name   Reason Excluded Under Part D  
No longer prescribed without 
Albuterol* 
sulfate 
Fexofenadine HCl*  Nonprescription drug  
Folic acid*   Vitamin or mineral product  
Ergocalciferol (Vitamin D)*   Vitamin or mineral product  
2
Source:  OIG analysis of  formulary inclusion of drugs commonly used by dual eligibles, 2015.  
*These drugs were also on the 2014 reports list of drugs commonly used by dual eligibles 
and not covered under Part D.  
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 26  Andrew M. Slavitt 
APPENDIX D 
 
Formulary Inclusion of Stand-Alone Prescription Drug Plans* and Medicare 
Advantage Prescription Drug Plans**, by Region 
 
Table D-1: PDP Formularies Inclusion of Commonly Used Drugs, by Region 
PDP  Number of   Average Rate of   Maximum 
State(s)   Minimum Rate  
Region  PDPs  Inclusion by  Formularies   Rate  
1  Maine, New Hampshire  27  94%   89%   99%  
Connecticut, Massachusetts,  26  94%   89%   98%  
2 
Rhode Island, Vermont  
3  New  York   24  94%   89%   98%  
4  New  Jersey   28  94%   89%   99%  
Delaware, the District of  26  94%   89%   99%  
5 
Columbia, Maryland 
6  Pennsylvania, West Virginia  26  94%   89%   100%  
7  Virginia  30  94%   89%   99%  
8  North Carolina   28  94%   89%   99%  
9  South Carolina   30  95%   89%   99%  
10  Georgia  29  94%   89%   99%  
11  Florida   26  94%   89%   98%  
12  Alabama, Tennessee  29  94%   89%   99%  
13  Michigan  30  94%   89%   99%  
14  Ohio   30  94%   89%   99%  
15  Indiana, Kentucky  30  94%   89%   99%  
16  Wisconsin  28  94%   89%   99%  
17  Illinois  32  94%   88%   99%  
18  Missouri  30  94%   89%   99%  
19  Arkansas  28  95%   89%   99%  
20  Mississippi   27  94%   89%   99%  
21  Louisiana  27  94%   89%   99%  
22  Texas   31  94%   89%   99%  
23  Oklahoma   30  94%   89%   99%  
24  Kansas  28  94%   89%   99%  
Iowa, Minnesota, Montana,  29  94%   89%   99%  
25  Nebraska, North Dakota, South 
Dakota, Wyoming 
26  New  Mexico  30  94%   89%   99%  
27  Colorado   29  94%   89%   99%  
28  Arizona  29  94%   89%   99%  
29  Nevada   31  94%   89%   99%  
30  Oregon, Washington  29  94%   89%   99%  
31  Idaho, Utah   30  94%   89%   99%  
32  California  31  94%   89%   99%  
33  Hawaii  24  94%   89%   99%  
34  Alaska   23  94%   89%   99%  
Source:  OIG analysis of  formularies inclusion of drugs commonly used by dual eligibles, 2015. 
 
*PDP.  
**MA-PD.  
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)   Page 27  Andrew M. Slavitt 
Table D-2: MA-PD Formularies Inclusion of Commonly Used Drugs, by Region  
Average Rate of  
MA-PD   Number of 
State(s)   Inclusion by   Minimum Rate   Maximum Rate  
Region***   MA-PDs  
Formularies  
1  Maine, New Hampshire  37  95%   89%   100%  
Connecticut, Massachusetts, Rhode  85  96%   90%   100%  
2 
Island, Vermont  
3  New  York   187  95%  90%  99%  
4  New  Jersey   37  94%  89%  98%  
Delaware, the District of Columbia,  25  95%   91%   100%  
5 
Maryland  
6  Pennsylvania, West Virginia  129  96%   90%   100%  
7  North Carolina, Virginia  107  96%   89%   100%  
8  Georgia, South Carolina   62  96%   89%   100%  
9  Florida   219  96%   89%   100%  
10  Alabama, Tennessee  83  96%  92%  98%  
11  Michigan  61  96%   90%   100%  
12  Ohio   91  95%   89%   100%  
13  Indiana, Kentucky  79  96%  89%  98%  
14  Illinois, Wisconsin  124  96%   86%   100%  
15  Arkansas, Missouri  70  96%  89%  99%  
16  Louisiana, Mississippi  62  96%  93%  98%  
17  Texas   128  95%  89%  99%  
18  Kansas, Oklahoma  49  96%  89%  98%  
Iowa, Minnesota, Montana, Nebraska,  79  96%   88%   100%  
19  North Dakota, South Dakota, 
Wyoming 
20  Colorado, New  Mexico  66  97%   89%   100%  
21  Arizona  72  96%  89%  99%  
22  Nevada   30  95%  89%  99%  
23  Idaho, Oregon, Utah, Washington   157  96%   88%   100%  
24  California  283  95%   89%   100%  
25  Hawaii  17  97%   94%   100%  
Source:  OIG analysis of  formularies inclusion of drugs commonly used by dual eligibles, 2015. 
***Region 26, which covers Alaska, had no MA-PDs available for 2015. 
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles:   2015 (OEI-05-15-00120)