U.S. Department of Health and Human Services 
 
Office of Inspector General 
 
 
Part D Plans Generally Include 
Drugs Commonly Used by 
Dual Eligibles: 2020 
 
Suzanne Murrin 
Deputy Inspector General for Evaluation and Inspections 
June 2020, OEI-05-20-00190  U.S. Department of Health and Human Services 
O  ffice of Inspector General 
 
Report in Brief 
 
Ju ne 2020, OEI-05-20-00190 
 
Part D Plans Generally Include Drugs 
Why OIG Did This Review 
The ACA requires OIG to conduct a 
Commonly Used by Dual Eligibles: 2020 
study of the extent to which 
formularies used by Medicare Part 
What OIG Found 
D plans include drugs commonly  Key Takeaway 
Overall, we found that the rate of Part D plan 
used by full-benefit dual eligible 
Overall, we found that  formularies inclusion of the 195 drugs commonly 
individuals (i.e., individuals who are 
the rate of Part D plan  used by dual eligibles (i.e., individuals who are 
eligible for both Medicare and full 
formularies inclusion  eligible for both Medicare and Medicaid) is high, 
Medicaid benefits).  These 
of the drugs commonly  with some variation.  On average, Part D plan 
individuals generally get drug 
used by dual eligibles is  formularies include 97 percent of the 
coverage through Medicare Part D.   high, with some 
195 commonly used drugs.  In addition, 75 percent 
Pursuant to the ACA, OIG must  variation.  Because 
of the commonly used drugs are included by all 
annually issue a report with  some variation exists in 
Part D plan formularies.  These results are largely 
recommendations as appropriate.   formularies inclusion 
unchanged from the Office of Inspector Generals 
This is the tenth report OIG has  and utilization 
(OIGs) findings for formularies reported in the 
management of these 
produced to meet this mandate. 
drugs, some dual  mandated annual report from 2019, as well as 
How OIG Did This Review  eligibles may need to  from the findings in our reports from 
make additional efforts  2011 through 2018. 
For this report, we determined 
(e.g., appeal coverage 
whether the 448 unique formularies 
decisions) to access the  We also found that the percentage of drugs to 
used by the 4,610 Part D plans 
drugs they take.    which plan formularies applied utilization 
operating in 2020 cover the 200 
  management tools increased slightly between 
drugs most commonly used by 
2019 and 2020.  On average, formularies applied utilization management 
dual eligibles.  We also determined 
tools to 29 percent of the unique drugs we reviewed in 2020, an increase of 
the extent to which plan 
1 percentage point from 2019. 
formularies applied utilization 
management tools to those  What OIG Concludes 
commonly used drugs.  To create  Inclusion rates for the 195 drugs commonly used by dual eligibles are largely 
the list of the 200 drugs most  unchanged from the inclusion rates listed in our previous reports.  Part D 
commonly used by dual eligibles,  formularies include roughly the same high percentage of these commonly 
we used data from the 2017  used drugs in 2020 as they did in 2019.   
Medicare Current Beneficiary 
Surveythe most recent data  As mandated by the Patient Protection and Affordable Care Act (ACA), OIG 
available at the time of our study.   will continue to monitor and produce annual reports on the extent to which 
Of the top 200 drugs, 195 are  Part D plan formularies cover drugs that dual eligibles commonly use.  In 
eligible for Part D prescription drug  addition, OIG will continue to monitor Part D plan formularies application of 
coverage, 2 are excluded from  utilization management tools to these drugs.  OIG has no recommendations 
coverage, 1 is no longer offered as  at this time. 
a prescription, and 1 is a medical 
 
supply item covered by Part D.  
One additional drug is eligible for 
Part D prescription drug coverage.  
However, we did not include it in 
our analysis because we could not 
confidently project the use of this 
dr ug to the entire dual eligible   
po pulation.   
   
TABLE OF CONTENTS 
 
 
 
 
BACKGROUND  1 
Methodology  7 
FINDINGS  12 
Part D plan formularies include between 89 and 100 percent of the drugs commonly used by  12 
dual eligibles 
Seventy-five percent of the drugs commonly used by dual eligibles are included in all Part D  14 
plan formularies 
The percentage of commonly used drugs to which plan formularies applied utilization  16 
management tools increased slightly between 2019 and 2020 
CONCLUSION   19 
APPENDICES  21 
A.  Section 3313 of the Patient Protection and Affordable Care Act of 2010  21 
B.  List of mandated OIG reports examining dual eligibles access to drugs under Part D  22 
C.  Commonly used drugs and rates of inclusion by formularies  23 
D.  Five drugs commonly used by dual eligibles were excluded from this analysis  30 
E.  Rates at which prescription drug plan formularies associated with stand-alone or Medicare  31 
Advantage plans include commonly used drugs, by region 
ACKNOWLEDGMENTS AND CONTACT  33 
ABOUT THE OFFICE OF INSPECTOR GENERAL  34 
   
BACKGROUND 
 
 
Objectives 
1.  To determine the extent to which Part D plan formularies cover the drugs 
commonly used by dual eligibles. 
2.  To determine the extent to which Part D plan formularies applied utilization 
management tools to the drugs commonly used by dual eligibles. 
 
Pursuant to the Medicare Prescription Drug, Improvement, and Modernization Act of 
2003 (MMA), comprehensive prescription drug coverage under Medicare Part D is 
available to all Medicare beneficiaries through prescription drug plans (PDPs) and 
Medicare Advantage prescription drug plans (MA-PDs), hereinafter referred to 
collectively as Part D plans.1   
For beneficiaries who are eligible for both Medicare and Medicaid (hereinafter 
referred to as dual eligibles), Medicare subsidizes 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, the dual eligibles are responsible for paying the premium amounts above 
that benchmark. 
To control costs and ensure the safe use of drugs, Part D plans are allowed to 
establish formularies from which they may omit certain drugs from prescription 
coverage and are allowed to control drug utilization through utilization management 
tools.2  These tools include prior authorization, quantity limits, and step therapy.3  In 
addition, Centers for Medicare & Medicaid Services (CMS) authorized Part D plans to 
_____________________________________________________________________________________________________________________________ 
1 MMA, P.L. No. 108-173 (enacted Dec. 8, 2003),  101, Social Security Act  1860D-1(a). 
2 A formulary is a list of drugs covered by a Part D plan.  Part D plans can exclude certain drugs from their 
formularies and can control utilization for formulary-included drugs within certain parameters.  Social 
Security Act  1860D-4(b) and (c). 
3 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 riskier drug therapy. 
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 1  use indication-based formulary design beginning in contract year 2020 to further 
control drug utilization.4 
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. 
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 
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.6  As of January 
2020, approximately 47 million of the 62.2 million Medicare beneficiaries were 
enrolled in a Part D plan. 
Part D plans are administered by private companiesknown as plan sponsorsthat 
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.  In 2020, plan 
sponsors offer 4,610 unique Part D plans, with many plan sponsors offering multiple 
Part D plans.  
Dual Eligibles Under Medicare Part D 
Approximately 12.2 million Medicare beneficiaries are dual eligibles.  For about 
8.7 million dual eligibles, referred to as full-benefit dual eligibles, Medicaid provides 
full Medicaid benefits, including Medicaid-covered services, and may also assist 
beneficiaries with premiums and cost sharing for Medicare fee-for-service or 
Medicare managed care.  For other dual eligibles, Medicaid does not provide 
Medicaid-covered services, but provides assistance with beneficiaries Medicare 
premiums or cost sharing, depending on their level of income and assets.7 
Dual eligibles are a particularly vulnerable population.  Overall, most dual eligibles 
have very low incomes86 percent have annual incomes below 150 percent of the 
_____________________________________________________________________________________________________________________________ 
4 Indication-based formulary design allows Part D plans to limit certain drugs to specific indications.  
However, if a plan limits coverage of a drug to a specific indication, the plan must ensure that there is a 
therapeutically similar drug for other indications.  
5 MMA, P.L. No. 108-173 (enacted Dec. 8, 2003),  101, Social Security Act  1860D-1(a). 
6 CMS, Prescription Drug Benefit Manual (PDBM), ch. 1,  10.1. 
7 Medicare Payment Advisory Commission and Medicaid and CHIP Payment and Access Commission, 
Data Book: Beneficiaries Dually Eligible for Medicare and MedicaidJanuary 2018.  Accessed at 
https://www.macpac.gov/wp-content/uploads/2017/01/January-2018-Beneficiaries-Dually-Eligible-for-
Medicare-and-Medicaid-Data-Book.pdf on April 9, 2019. 
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 2  Federal poverty level, compared with 22 percent of all other Medicare beneficiaries.  
Additionally, dual eligibles are in worse health than the average Medicare 
beneficiaryhalf are in fair or poor health, more than twice the rate of others in 
Medicare.8  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.9  
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.10, 11  If dual eligibles enroll in Part D plans 
with premiums higher than the regional benchmark, the dual eligibles are responsible 
for paying the premium amounts above that benchmark.12  
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.13  The PDPs to which CMS 
assigns dual eligibles must meet certain requirements, such as having a premium at or 
below the regional benchmark amount and offering basic prescription drug coverage 
(or equivalent).14  Basic prescription drug coverage is defined in terms of benefit 
structure (initial coverage, coverage gap, and catastrophic coverage) and costs (initial 
deductible and coinsurance). 
Given that assignment is done on a random basis, dual eligibles may be enrolled in 
PDPs that do not cover the specific drugs the dual eligibles use, or that only cover the 
_____________________________________________________________________________________________________________________________ 
8 Kaiser Family Foundation, Medicares Role for Dual Eligible Beneficiaries.  Accessed at 
http://www.kff.org/medicare/upload/8138-02.pdf on March 19, 2019. 
9 MMA, P.L. No. 108-173 (enacted Dec. 8, 2003),  101, Social Security Act  1860D-1(a). 
10 Social Security Act  1860D-14(b); 42 CFR  423.780(b)(2)(i). 
11 Dual eligibles residing in territories are not eligible to receive cost sharing assistance from Medicare.  
Consequently, there are no benchmarks for Part D plans offered in the territories.  Social Security Act 
 1860D-14(a)(3)(F). 
12 The ACA established a de minimus 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 minimus amount.  ACA, P.L. No. 111-148 (enacted Mar. 23, 2010),  3303, Social 
Security Act  1860D 14(a)(5).  For 2019, CMS set the de minimis amount at $2 above the regional 
benchmark. 
13 CMS, PDBM, ch. 3,  40.1.4. 
14 Ibid. 
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 3  specific drugs the dual eligibles use for a limited set of indications.  However, unlike 
the general Medicare population, dual eligibles have up to three special election 
periods during the first 9 months of the year to find plans that cover the prescription 
drugs the dual eligibles require and switch plans if needed.15  When they use a special 
election period to change plans, dual eligibles 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 the dual eligibles current 
PDPs will have premiums above the regional benchmark premium for the following 
year.16  For dual eligibles who were randomly assigned to their current PDPs, CMS 
chooses new PDPs that will have premiums at or below the regional benchmark 
premium.17  For 2020, CMS reported reassigning approximately 433,473 Medicare 
beneficiariesincluding, but not exclusively, dual eligiblesbecause 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 
balance Medicare beneficiaries needs for adequate prescription drug coverage with 
Part D plan sponsors needs to contain costs.  Generally, a formulary must include at 
least two drugs in each therapeutic category or class.18, 19  In addition, Part D plans 
must include drugs covered by Part D in certain categories and classes.20   
Starting in 2020, Part D plans are permitted to use indication-based formulary design.  
Plans that use this type of design limit formulary coverage of drugs to certain 
indications, or uses approved by the Food and Drug Administration (FDA).  However, 
for each drug limited to certain indications, these plans must ensure that their 
_____________________________________________________________________________________________________________________________ 
15 83 Fed. Reg. 16440, 1651419 (Apr. 16, 2018).  In general, Medicare beneficiaries can switch Part D 
plans only once a year during a defined enrollment period.  In previous years, dual eligibles could switch 
Part D plans monthly to find plans that covered the drugs they required.  
16 CMS, PDBM, ch. 3,  40.1.5.  CMS also reassigns beneficiaries who were assigned to plans that were 
terminated and will not be offered in the following year.  For 2020, no beneficiaries were reassigned 
because of terminated plans. 
17 Ibid. 
18 CMS, PDBM, ch. 6,  30.2.1. 
19 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. 
20 Social Security Act  1860D-4(b)(3)(G).  Current Part D policy requires sponsors to include in their 
formularies all drugs in six categories or classes, except in limited circumstances: (1) antidepressants; (2) 
antipsychotics; (3) anticonvulsants; (4) immunosuppressants for treatment of transplant rejection; (5) 
antiretrovirals; and (6) antineoplastics.  CMS, PDBM, ch. 6,  30.2.5.   
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 4  formularies also cover at least one therapeutically similar drug for the nonformulary 
indications.21 
Part D plans may also control drug utilization by applying utilization management 
tools.  These tools include the following: 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 that Part D plans make regarding 
individual formularies, certain categories of drugs are excluded from Medicare Part D 
prescription drug coverage as mandated by the MMA.22  For example, prescription 
vitamins, prescription mineral products, and nonprescription drugs are excluded from 
Part D prescription drug coverage.23 
Until 2013, barbiturates and benzodiazepines were excluded from Part D prescription 
drug coverage.  However, the Patient Protection and Affordable Care Act (ACA) 
reversed this exclusion, removing these two drug types from the list of drug classes 
ineligible for such coverage.24, 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, as well as all drugs 
in specified therapeutic categories or classes.26  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 (i.e., drugs from the same therapeutic 
_____________________________________________________________________________________________________________________________ 
21 CMS, Indication-Based Formulary Design Beginning in Contract Year (CY) 2020.  Accessed at 
https://www.cms.gov/Research-Statistics-Data-and-Systems/Computer-Data-and-
Systems/HPMS/Downloads/HPMS-Memos/Weekly/SysHPMS-Memo-2018-Aug-29th.pdf on 
March 22, 2019. 
22 MMA, P.L. No. 108-173 (enacted Dec. 8, 2003),  101, Social Security Act  1860D-2(e). 
23 Social Security Act  1860D-2(e)(2), 1927(d)(2). 
24 ACA, P.L. No. 111-148 (enacted Mar. 23, 2010),  2502, Social Security Act  1927(d). 
25 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 March 20, 2019. 
26 CMS, PDBM, ch. 6,  30.2.7. 
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 5  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 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.28, 29  
Exceptions and appeals process 
CMS has implemented an exceptions and appeals process whereby beneficiaries can 
request coverage of nonformulary drugs or exceptions to utilization management 
tools that apply to formulary drugs.  When a Part D plan receives a prescribers 
statement supporting an exception request, the plan must notify the beneficiary of its 
determination within 72 hours or, for expedited requests, within 24 hours.30  If the 
beneficiarys plan makes an adverse determination, the beneficiary has the right to 
appeal.31  If the plan continues to deny the beneficiarys request, the beneficiary has 
additional appeal rights and may continue to appeal until those rights are exhausted.  
Alternatively, the beneficiary can work with his or her prescriber to determine whether 
there is an appropriate, therapeutically equivalent alternative drug on the plans 
formulary. 
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 fill of a prescription when the beneficiary requests 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.32  The temporary fill 
accommodates beneficiaries immediate drug needs the first time the beneficiary 
attempts to fill a prescription.  The transition period also allows the beneficiary time to 
work with his or her prescribing physician(s) to obtain prescriptions for therapeutically 
alternative drugs or to request a formulary exception from the Part D plan. 
_____________________________________________________________________________________________________________________________ 
27 Ibid. 
28 CMS, PDBM, ch. 6,  30.2.2. 
29 CMS, PDBM, ch, 6,  30.2.7. 
30 CMS, Parts C & D Enrollee Grievances, Organization/Coverage Determinations, and Appeals Guidance, 
 40.5.3. 
31 CMS, Parts C & D Enrollee Grievances, Organization/Coverage Determinations, and Appeals Guidance, 
 50. 
32 CMS, PDBM, ch. 6,  30.4.4. 
 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 6  Related OIG Work 
In 2006, the Office of Inspector General (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.33   
In 2011, OIG issued the first annual mandated report examining dual eligibles access 
to drugs under Medicare Part D.  (See Appendix A for the statutory mandate.)  We 
have released an annual mandated report each year since then.  (See Appendix B for a 
list of these reports.)  The current report is the tenth report released. 
Methodology 
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 2020.  As part of 
our assessment, we included dual eligibles enrollment data from January 2020, the 
most recent enrollment data available from CMS at the time of our study.  We also 
compared the results of our 2020 study with those of our 2019 study.34   
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 Medicare Current Beneficiary 
Survey (MCBS)i.e., the 2017 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, 195 are eligible for coverage under Part D.  In this report, we refer to these 
195 Part D-eligible, high-utilization drugs as commonly used drugs. 
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. 
In the current (2020) report and the previous seven reports, we have also gone 
beyond the ACAs mandate by examining the utilization management tools that Part 
D plan formularies apply to the drugs commonly used by dual eligibles.  These tools 
_____________________________________________________________________________________________________________________________ 
33 OIG, Dual Eligibles Transition: Part D Formularies Inclusion of Commonly Used Drugs, 
OEI-05-06-00090, January 2006. 
34 OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2019, OEI-05-19-00220, 
June 2019. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 7  may affect dual eligibles access, even in cases in which formularies include the 
commonly used drugs.  Analyzing the extent 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 2017 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, prescription drug costs, and prescription drug 
utilization.  The 2017 MCBS Cost and Use data were the most recent data available at 
the time of our study.  Historically, the list of the 200 drugs with the highest utilization 
by dual eligibles has remained largely unchanged from year to year.  The list for 
2020 overlapped by 91 percent with the list for 2019, which in turn overlapped by 
88 percent with the list for 2018.35  
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 were interviewed three times per year and asked 
what drugs they were taking and whether they had started taking any new drugs 
since the previous interview.  The MCBS also includes Part D prescription drug events 
for surveyed Medicare beneficiaries.  In 2016, the MCBS surveyed 15,207 Medicare 
beneficiaries, of whom 2,224 were dual eligibles who had used prescription drugs 
during the year (out of 3,790 dual eligible survey respondents). 
First DataBank National Drug Data File.  We used the February 2020 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).36 
Part D plan data.  In January 2020, we collected from CMS the formulary data and 
the plan data for Part D plans operating in 2020.  The formulary data includes Part D 
plans formularies and utilization management tools for plans operating in 2020.  In 
2020, there are 448 unique formularies offered by 4,610 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 2020 enrollment data for Part D plans.  These data provide the 
number of dual eligibles enrolled in each Part D plan as of January 2020. 
_____________________________________________________________________________________________________________________________ 
35 In 2019, we used 2016 data.  In 2018, we used 2013 data.  In 2017, we used 2012 data. 
36 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: 2020 
OEI-05-20-00190  Background | 8  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 
2017 MCBS.  We excluded respondents from territories because they are not 
eligible to receive cost sharing assistance under Part D.  The MCBS listed 
150,560 drug events for 2,224 dual eligibles who did not reside in territories.37   
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 150,560 drug events associated with 
858 drugs. 
3.  We ranked the 858 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 C. 
5.  We removed all drugs not covered under Part D.  Of the 200 drugs with the 
highest utilization, 195 are eligible under Part D.  Two fall into a drug category 
excluded under Part D.  (For details on the two drugs excluded under Part D, 
see Appendix D.)  One drug is no longer offered as a prescription.  An 
additional drug is eligible for Part D prescription drug coverage.  However, we 
did not include it in our analysis becausealthough it is eligible under Part 
DMedicare considers it to be a medical supply item.  We did not include 
another drug in our analysis because we could not confidently project the use 
of this drug to the entire dual eligible population.  
Formulary analysis 
We analyzed the 448 unique Part D plan formularies to determine their rates of 
inclusion of the 195 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.   
_____________________________________________________________________________________________________________________________ 
37 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 2017.  For example, one MCBS survey 
respondent reported taking alprazolam 11 times in 2017.  We counted this beneficiary/drug combination 
as 11 drug events. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 9  Low rates of inclusion by formularies.  We determined which of the 195 commonly 
used drugs had low rates of inclusion by formularies by counting how many of the 
448 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 195 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 195 drugs that we reviewed.  The tools that 
we reviewed are prior authorization, quantity limits, and step therapy. 
To determine the extent to which Part D plan formularies applied utilization 
management tools to the 195 commonly used drugs, 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 195 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 January 2020 to 
Part D plans available in 2020. 
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 developed our list of commonly used drugs by 
using a sample of dual eligibles who responded to the MCBS, a particular dual eligible 
might not use any of the drugs on our list.  However, the drugs most commonly used 
by dual eligible participants in the 2017 MCBS survey account for 89 percent of all 
prescriptions dispensed to the dual eligible respondents in the 2017 MCBS. 
We also did not assess the impact of indication-based formulary design on dual 
eligibles access to prescription drugs.  The formulary data we used for this analysis 
does not include sufficient details for us to determine which drugs were covered for 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 10  only a limited number of indications.  As a result, some beneficiaries included in our 
analysis may not be able to access all commonly used drugs covered by their Part D 
plans because certain drugs are not available for all indications. 
Standards 
We conducted this study in accordance with the Quality Standards for Inspection and 
Evaluation issued by the Council of the Inspectors General on Integrity and Efficiency. 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Background | 11   
FINDINGS 
 
Part D plan formularies include between 89 and 100 percent of 
the drugs commonly used by dual eligibles 
On average, Part D plan formularies include 97 percent of the drugs commonly used 
by dual eligibles.  Of the 448 unique formularies used by Part D plans in 2020, 
7 formularies include 100 percent of the commonly used drugs.  At the other end of 
the inclusion range, one formulary includes 89 percent of the commonly used drugs.  
Exhibit 1 provides a breakdown of the formularies inclusion rates for the drugs most 
commonly used by dual eligibles.  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 the formularies do not include all of the drugs we identified as 
commonly used by dual eligibles.  
Exhibit 1: About 80 percent of the 448 Part D plan formularies cover at least 
97 percent of the drugs commonly used by dual eligibles. 
 
      Source: OIG analysis of formulary inclusion of drugs commonly used by dual eligibles, 2020. 
Part D plan formularies rates of inclusion of the drugs commonly used by dual 
eligibles in 2020 did not change from the rates in 2019.  The average rate of inclusion 
remained at 97 percent between 2019 and 2020.  The range of inclusion rates also 
remained the same between 2019 and 2020; rate of inclusion ranged from 89 to 
100 percent in both 2019 and 2020. 
Nationally, PDP and MA-PD formularies have similar rates of inclusion of the drugs 
commonly used by dual eligibles, averaging 96 percent and 97 percent, respectively.  
For PDP formularies, the rates of inclusion range from 89 to 100 percent.  For MA-PD 
formularies, the rates of inclusion range from 90 to 100 percent.  Eight formularies
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Findings | 12  2 percent of the 448 unique formularies used by Part D plans in 2020are 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 99 percent of the commonly used drugs, while every MA-PD region has a plan 
that includes at least 98 percent of the commonly used drugs.  Appendix E 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 97 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 89 percent to 
100 percent.  Approximately 82 percent of dual eligibles are enrolled in Part D plans 
with premiums below the regional benchmark. 
Most 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 11 million dual eligibles enrolled in Part D plans, approximately 
95 percent are enrolled in Part D plans that use formularies that include at least 
90 percent of the commonly used drugs.  Five percent of dual eligibles are enrolled in 
Part D plans that use formularies that include less than 90 percent of these drugs.  
Exhibit 2 provides a breakdown of dual eligibles enrollment in Part D plans by the 
rates at which the plans formularies include the commonly used drugs. 
Exhibit 2: Most dual eligibles are enrolled in Part D plans that include at 
least 90 percent of the drugs commonly used by dual eligibles. 
Part D Plans With Formularies That Include:  Number of Dual  Percentage of Dual 
Eligibles Enrolled  Eligibles Enrolled 
100% of commonly used drugs  8,850  0.1% 
95% to 99% of commonly used drugs  9,493,260  86.7% 
90% to 94% of commonly used drugs  883,689  8.1% 
86% to 89% of commonly used drugs  568,034  5.2% 
     Total  10,953,833  100%* 
Source: OIG analysis of formulary inclusion of drugs commonly used by dual eligibles and dual eligibles enrollment, 
2020.  
*Percentages do not add up to 100 percent due to rounding. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Findings | 13  The percentage of dual eligibles enrolled in Part D plans that include at least 
90 percent of the drugs commonly used by dual eligibles increased slightly from 
94 percent in 2019 to 95 percent in 2020. 
Seventy-five 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 can be confident that regardless of the Part D plan in which 
they are enrolled, the plans formulary will include many of these drugs.  By drug, 
inclusion in formularies ranges from 46 percent to 100 percent.  At one end of the 
range, there is a drug that is included in 46 percent of Part D plan formularies, and, at 
the other end, 146 drugs are included in all plan formularies.  The average rate of 
inclusion in formularies is 97 percent.  Exhibit 3 shows the rates at which formularies 
include the 195 drugs.  Appendix C lists the 195 drugs and the rates at which 
formularies include them. 
Exhibit 3: Nearly three quarters of the drugs most commonly used by dual 
eligibles are included in all Part D plan formularies. 
Percentage  Percentage of the 195 Commonly 
of the 448  Used Drugs Included in Formularies 
Formularies 
100%  75% 
(146 drugs) 
85% to 99%  17% 
(34 drugs) 
76% to 84%  4% 
(7 drugs) 
46% to 75%  4% 
(8 drugs) 
     Total  100% 
(195 drugs) 
Source: OIG analysis of formulary inclusion of drugs commonly used by dual eligibles, 2020. 
The rates at which formularies include the drugs commonly used by dual eligibles 
increased in 2020.  Formularies included 75 percent of the commonly used drugs in 
2020, compared to 72 percent in 2019.   
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.  Exhibit 4 provides the percentage of 
formularies covering each of these eight drugs. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Findings | 14  The drugs that make up this group include both brand-name and generic drugs and 
are used to treat a variety of primary indications.  Seven of the eight drugs are 
brand-name drugs, which are typically more costly than generic drugs.  As for the 
primary indications, four of the eight drugs are used for diabetes therapy, and the 
remaining four drugs treat a variety of conditions, including asthma and chronic 
obstructive pulmonary disorder. 
Exhibit 4: Drugs included by less than 75 percent of Part D plan formularies 
were most frequently used for diabetes therapy. 
 
Generic Name of Drug  Primary  Rate of Inclusion by 
Indication(s)  Formularies   
Insulin detemir  Diabetes  74%   
Tiotropium bromide*  Chronic  72%   
obstructive 
 
pulmonary 
disease   
Insulin aspart*  Diabetes  71%   
Budesonide/formoterol  Asthma  70%   
fumarate 
 
Canagliflozin*  Diabetes  58% 
 
Solifenacin succinate*  Overactive  54% 
bladder,   
incontinence 
 
Dexlansoprazole*  Gastroesophageal  53% 
 
reflux disease 
 
Insulin lispro*  Diabetes  46% 
 
Source: OIG analysis of formulary inclusion of drugs commonly used by dual eligibles, 2020. 
* These drugs also had low rates of formulary inclusion in 2019. 
Although Part D formularies frequently omit these eight drugs, they all cover other 
drugs in the same respective therapeutic classes.  For each of these 8 drugs, 
100 percent of formularies cover at least 1 drug in the same therapeutic class that is 
also on the list of 195 drugs commonly used by dual eligibles. 
The number of drugs included by less than 75 percent of formularies remained the 
same in 2019 and 2020with eight drugs both years.  There are six drugs with low 
inclusion rates in 2020 that were also on the list of commonly used drugs with low 
inclusion rates in our 2019 report; we note these six drugs with asterisks in 
Exhibit 4 (above).  Five of these six drugs were also on the list of drugs with low 
inclusion rates in our 2018 report. 
There are multiple potential reasons why a commonly used drug might be included 
by less than 75 percent of formularies: 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Findings | 15    In the case of two of the eight drugsinsulin lispro and insulin aspartFDA 
has issued MedWatch Safety Alerts because of the drugs delivery systems, 
which can vary and sometimes result in situations in which patients do not get 
the insulin they think they injected.38, 39 
  The American Geriatrics Society cautions against certain uses of proton pump 
inhibitor drugs and drugs with strong anticholinergic properties.  
Dexlansoprazole is a proton pump inhibitor drug, and solifenacin succinate 
has strong anticholinergic properties.40  
If a formulary does not include a particular drug, a dual eligible has three options, all 
of which require taking additional action: 
  Obtaining a therapeutically equivalent alternative drug that is included by the 
plans formulary.  (This option necessitates getting a new prescription from the 
dual eligibles doctor.) 
  Going through an appeals process to obtain coverage of a nonformulary drug 
by submitting a statement of medical necessity from the dual eligibles 
physician.41 
  Switching to a Part D plan with a formulary that does include the drug.  Dual 
eligibles can make such a switch once per calendar quarter during the first 
9 months of the year, with the new coverage becoming effective the following 
month.42 
The percentage of commonly used drugs to which plan 
formularies applied utilization management tools increased 
slightly between 2019 and 2020 
For the unique drugs that compose the list of commonly used drugs, the percentage 
to which Part D plan formularies applied utilization management tools increased 
slightly from 28 percent in 2019 to 29 percent in 2020.  Plans with premiums below 
the regional benchmarks used utilization management tools less frequently than all 
plans; formularies of these plans used utilization management tools for 24 percent of 
their drugs.  See Exhibit 5 for a breakdown of the 2019 percentage of unique drugs to 
_____________________________________________________________________________________________________________________________ 
38 FDA, Caution When Using Pen Needles To Inject Medicines: FDA Safety Communication.  Accessed at 
https://www.drugs.com/fda-alerts/1341-0.html on April 2, 2019. 
39 Ibid. 
40 American Geriatrics Society, American Geriatrics Society 2015 Updated Beers Criteria for Potentially 
Inappropriate Medication Use in Older Adults. 
41 CMS, Parts C & D Enrollee Grievances, Organization/Coverage Determinations, and Appeals Guidance, 
ch. 18,  40.5. 
42 83 Fed. Reg. 16440, 16519 (Apr. 16, 2018).  
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Findings | 16  which Part D plan formularies applied utilization management tools as well as the 
2020 percentage. 
Exhibit 5: Part D plan formularies application of utilization management tools increased 
slightly between 2019 and 2020 for commonly used drugs. 
Percentage of Unique  Number of 2019  Percentage of  Number of 2020  Percentage of 
Drugs to Which Plan  Part D Plan  2019 Part D Plan  Part D Plan  2020 Part D Plan 
Formularies Applied  Formularies  Formularies  Formularies  Formularies 
Utilization Management 
Tools  
Greater than 40%  68  17%  72  16% 
30% to 39%  94  23%  118  26% 
20% to 29%  137  34%  151  34% 
10% to 19%  82  21%  100  22% 
Less than 10%  20  5%  7  2% 
     Totals  401  100%  448  100% 
Source: OIG analysis of formulary inclusion of drugs commonly used by dual eligibles, 2020. 
Although utilization management tools can restrict beneficiaries access to drugs, they 
are important tools for managing costs in Medicare and ensuring the appropriate 
utilization of drugs.  For example, in 2013, CMS set forth expectations for reviews of 
opioid overutilization to help ensure that opioids are appropriately prescribed and 
used.43  
The percentage of unique drugs for which formularies applied the utilization 
management tools of quantity limits, prior authorization, or step therapy44 changed 
slightly between 2019 and 2020.  Formularies applied quantity limits to 26 percent of 
drugs in 2020, an increase of 1 percentage point from 2019; require prior 
authorization for 4 percent of drugs; and require step therapy for 1 percent of unique 
drugs. 
The rate at which plan formularies applied specific utilization management tools 
varies widely.  In 2020, some formularies applied utilization management tools to very 
few of the unique drugs, whereas at the other end of the range, some formularies 
applied tools to 48 percent of the unique drugs.  More specifically, formularies 
applied quantity limits to between 0 and 44 percent of unique drugs; require prior 
authorization for between less than 1 percent and 10 percent of unique drugs; and 
require step therapy for between 0 and 7 percent of unique drugs. 
_____________________________________________________________________________________________________________________________ 
43 CMS, Improving Drug Utilization Review Controls in Part D (Excerpt from Final 2013 Call Letter 
04-02-2012).  Accessed at https://www.cms.gov/medicare/prescription-drug-
coverage/prescriptiondrugcovcontra/downloads/improving-dur-controls-in-part-d.pdf on April 8, 2019. 
44 See footnote 3 for explanations of quantity limits, prior authorization, and step therapy. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Findings | 17  Looking at enrollment across plans provides a slightly different picture than looking 
only at plans themselves.  On average, plan formularies in 2020 applied utilization 
management tools to 29 percent of unique drugs.  However, dual eligibles tend to be 
enrolled in plans with formularies that applied these tools at a slightly higher rate.  In 
2020, the median plan weighted by dual eligible enrollment applied such tools to 
31 percent of unique drugs; in 2019, the figure was 32 percent.  Similarly, the median 
plan weighted by overall Medicare enrollment applied these tools to 32 percent of 
unique drugs in 2020; in 2019, the figure was also 32 percent. 
Both dual eligibles and Medicare beneficiaries overall tend to be enrolled in plans 
with formularies that applied utilization management tools to between 20 and 
39 percent of unique drugs.  In 2020, 77 percent of dual eligibles and 71 percent of 
Medicare beneficiaries overall were enrolled in plans with formularies in this range.   
In 2020, there was an increase in the percentage of Medicare beneficiaries who were 
enrolled in plans that applied utilization management tools to more than 40 percent 
of unique drugs.  In 2019, 11 percent of dual eligibles and 14 percent of Medicare 
beneficiaries overall were enrolled in plans that applied utilization management tools 
to more than 40 percent of unique drugs.  These figures increased to 17 percent and 
22 percent, respectively, in 2020.  Exhibit 6 shows enrollment in Part D plans by dual 
eligibles and Medicare beneficiaries, as broken down by the percentages at which the 
plans formularies applied utilization management tools. 
Exhibit 6: The number of beneficiaries who were enrolled in plans that applied utilization 
management tools to more than 40 percent of unique drugs increased from 2019 to 2020. 
Percentage of Unique Drugs  Percentage of  Percentage of  Percentage of  Percentage of 
to Which Plan Formularies  Dual Eligibles  Medicare  Dual Eligibles  Medicare 
Applied Utilization  Enrolled, 2019  Beneficiaries  Enrolled, 2020  Beneficiaries 
Management Tools  Enrolled, 2019  Enrolled, 2020 
Greater than 40%  11%  14%  17%  22% 
30% to 39%  49%  51%  40%  44% 
20% to 29%  34%  28%  37%  27% 
10% to 19%  4%  4%  4%  4% 
Less than 10%  2%  3%  2%  3% 
     Totals  100%  100%  100%  100% 
Source: OIG analysis of formulary inclusion of drugs commonly used by Medicare beneficiaries and dual eligibles, 2020. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Findings | 18   
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 plan sponsors and for the Part D 
program.  By law and under CMS policy, Part D plan formularies do not generally 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 equivalent alternative drug.  Additionally, starting in 2020, Part D 
plans are authorized to limit access to some drugs to only certain indications, 
provided that they also include a therapeutically similar drug that covers 
nonformulary indications as well.  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 
97 percent of the commonly used drugs.  Part D plan formularies inclusion of the 
commonly used drugs ranges from 89 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.  However, some dual eligibles may 
be unable to access all drugs covered by their plans formularies to the extent that 
Part D sponsors implement indication-based formulary designs, beginning this year. 
Inclusion rates for the 195 drugs commonly used by dual eligibles are largely 
unchanged from those listed in OIGs 2019 report.  Part D plan formularies include 
roughly the same percentage of these commonly used drugs in 2020 as they did in 
2019.  Enrollment in plans that cover at least 90 percent of unique drugs increased 
slightly, with 95 percent of dual eligibles enrolled in such plans in 2020, compared to 
94 percent of dual eligibles in 2019.   
Because some variation exists in the inclusion by Part D plan formularies of the 
commonly used drugs and in Part D plan formularies application of utilization 
management tools to these drugs, some dual eligibles may need to make additional 
efforts to access the drugs they take.  These dual eligibles could appeal prescription 
drug coverage decisions, switch prescription drugs, or switch Part D plans.  Because 
these scenarios require additional effort by dual eligibles, they may result in 
administrative barriers to accessing certain prescription drugs. 
As mandated by the ACA, OIG will continue to monitor and produce annual reports 
on 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 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Conclusion / Recommendations | 19  application of utilization management tools to these drugs.  OIG has no 
recommendations at this time. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Conclusion / Recommendations | 20   
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: 2020 
OEI-05-20-00190  Appendix A | 21   
APPENDIX B 
 
List of mandated OIG reports examining dual eligibles access to 
drugs under Part D 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2011, 
OEI 05-10-00390, April 2011 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2012, 
OEI 05-12-00060, June 2012 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2013, 
OEI 15-13-00090, June 2013 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2014, 
OEI 05-14-00170, June 2014 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2015, 
OEI 05-15-00120, June 2015 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2016, 
OEI 05-16-00090, June 2016 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2017, 
OEI-05-17-00016, June 2017 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2018, 
OEI-05-18-00240, June 2018 
OIG, Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2019, 
OEI-05-19-00220, June 2019 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix B | 22   
APPENDIX C 
 
Commonly used drugs and rates of inclusion by formularies  
The 200 drugs with the highest utilization by dual eligibles. 
*Sample is from the 2017 MCBS.  Projections and confidence intervals are derived from its survey methodology. 
Generic Name  Sample  Projected  95-Percent Confidence Interval*  Number of  Percentage 
Size*  Drug  Formularies  of 
Events*  Including  Formularies 
Drug  Including 
Lower Bound  Upper Bound 
Drug 
Atorvastatin Calcium  3,506  26,514,761  23,033,296  29,996,226  448  100% 
Lisinopril  3,399  24,917,840  21,021,953  28,813,726  448  100% 
Amlodipine Besylate  3,292  23,984,655  20,528,125  27,441,185  448  100% 
Levothyroxine Sodium  4,649  23,948,599  20,854,803  27,042,395  448  100% 
Omeprazole  3,406  22,249,989  19,516,288  24,983,689  448  100% 
Metformin Hcl  2,567  21,366,050  18,296,220  24,435,879  448  100% 
Furosemide  4,107  18,523,601  16,142,689  20,904,514  448  100% 
Gabapentin  3,293  18,267,640  15,450,285  21,084,994  448  100% 
Metoprolol Tartrate  2,082  14,241,702  12,095,195  16,388,208  448  100% 
Simvastatin  1,828  14,228,468  11,645,305  16,811,630  448  100% 
Hydrocodone/Acetaminophen  2,647  14,094,248  11,761,058  16,427,438  448  100% 
Losartan Potassium  1,732  12,764,473  10,547,181  14,981,766  448  100% 
Potassium Chloride  2,628  12,023,377  9,989,348  14,057,406  448  100% 
Nystatin  2,768  11,830,879  7,823,249  15,838,510  448  100% 
Albuterol Sulfate  1,741  11,626,113  9,587,105  13,665,121  448  100% 
Hydrochlorothiazide  1,417  9,884,529  7,988,837  11,780,220  448  100% 
Metoprolol Succinate  1,600  9,533,225  7,982,869  11,083,581  448  100% 
Clopidogrel Bisulfate  1,329  9,147,802  7,443,727  10,851,878  448  100% 
Sertraline Hcl  1,621  8,472,094  6,834,658  10,109,530  448  100% 
Pravastatin Sodium  931  8,431,469  6,603,696  10,259,242  448  100% 
Insulin  1,034  8,167,922  6,313,173  10,022,671  447  100% 
Glargine,hum.Rec.Anlog 
Carvedilol  1,261  8,147,860  6,778,897  9,516,822  448  100% 
Pantoprazole Sodium  1,308  7,997,279  6,548,332  9,446,227  448  100% 
Alprazolam  1,431  7,873,074  5,711,557  10,034,591  429  96% 
Ranitidine Hcl  1,349  7,869,357  6,150,384  9,588,329  448  100% 
Tramadol Hcl  1,589  7,374,208  6,063,505  8,684,912  448  100% 
Glipizide  821  7,143,261  5,481,593  8,804,929  448  100% 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix C | 23  The 200 drugs with the highest utilization by dual eligibles, continued. 
Generic Name  Sample  Projected  95-Percent Confidence Interval*  Number of  Percentage 
Size*  Drug  Formularies  of 
Events*  Including  Formularies 
Drug  Including 
Lower Bound  Upper Bound  Drug 
Fluticasone Propionate  1,174  7,069,289  5,674,640  8,463,938  448  100% 
Warfarin Sodium  1,475  6,974,147  4,675,838  9,272,456  448  100% 
Tamsulosin Hcl  1,196  6,882,707  5,628,311  8,137,103  448  100% 
Trazodone Hcl  1,392  6,858,709  5,584,708  8,132,711  448  100% 
Quetiapine Fumarate  1,527  6,296,582  5,124,931  7,468,232  448  100% 
Citalopram Hydrobromide  1,187  5,942,838  4,468,612  7,417,065  448  100% 
Montelukast Sodium  1,008  5,914,073  4,551,247  7,276,899  448  100% 
Prednisone  999  5,727,417  4,639,144  6,815,690  448  100% 
Oxycodone  879  5,707,652  4,647,439  6,767,866  448  100% 
Hcl/Acetaminophen 
Escitalopram Oxalate  1,131  5,563,743  3,730,479  7,397,007  448  100% 
Atenolol  659  5,446,245  4,126,705  6,765,785  448  100% 
Sitagliptin Phosphate  806  5,377,234  4,208,739  6,545,729  429  96% 
Mirtazapine  1,320  5,366,122  4,161,516  6,570,727  448  100% 
Bupropion Hcl  755  5,155,729  3,469,359  6,842,098  448  100% 
Allopurinol  763  5,082,766  4,079,784  6,085,748  448  100% 
Divalproex Sodium  1,355  5,054,977  3,793,666  6,316,288  448  100% 
Duloxetine Hcl  1,035  5,029,421  3,971,712  6,087,130  448  100% 
Rosuvastatin Calcium  610  5,027,684  3,784,042  6,271,326  448  100% 
Donepezil Hcl  1,361  4,806,567  3,608,052  6,005,083  448  100% 
Ibuprofen  749  4,772,743  3,851,505  5,693,980  448  100% 
Clonazepam  915  4,521,679  3,110,574  5,932,783  448  100% 
Meloxicam  761  4,419,667  3,415,543  5,423,791  448  100% 
Esomeprazole Magnesium  664  4,317,203  3,218,639  5,415,766  345  77% 
Venlafaxine Hcl  706  4,219,899  3,292,550  5,147,249  448  100% 
Oxybutynin Chloride  722  4,205,538  2,896,338  5,514,739  448  100% 
Latanoprost  770  4,187,300  3,121,852  5,252,748  448  100% 
Insulin Aspart  630  4,083,231  3,001,193  5,165,270  316  71% 
Diltiazem Hcl  580  4,041,979  3,123,707  4,960,251  448  100% 
Isosorbide Mononitrate  675  4,016,792  2,974,421  5,059,162  448  100% 
Alendronate Sodium  533  3,974,224  3,079,871  4,868,578  448  100% 
Lisinopril/Hydrochlorothiazide  341  3,971,405  2,701,519  5,241,291  448  100% 
Hydralazine Hcl  585  3,927,628  3,023,269  4,831,987  448  100% 
Fluoxetine Hcl  678  3,898,533  2,839,966  4,957,101  448  100% 
Oxycodone Hcl  736  3,776,828  2,784,364  4,769,291  447  100% 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix C | 24  The 200 drugs with the highest utilization by dual eligibles, continued. 
Generic Name  Sample  Projected  95-Percent Confidence Interval*  Number of  Percentage 
Size*  Drug  Formularies  of 
Events*  Including  Formularies 
Drug  Including 
Lower Bound  Upper Bound  Drug 
Lorazepam  1,042  3,745,369  2,952,179  4,538,560  448  100% 
Pregabalin  658  3,693,834  2,845,309  4,542,358  448  100% 
Cyclobenzaprine Hcl  545  3,662,123  2,652,038  4,672,208  447  100% 
Memantine Hcl  1,088  3,624,505  2,716,486  4,532,523  448  100% 
Zolpidem Tartrate  490  3,513,758  2,208,838  4,818,679  440  98% 
Levetiracetam  770  3,496,607  2,450,170  4,543,044  448  100% 
Famotidine  839  3,428,420  2,569,603  4,287,236  445  99% 
Diclofenac Sodium  599  3,411,890  2,682,805  4,140,976  448  100% 
Baclofen  644  3,348,267  2,607,072  4,089,462  448  100% 
Aripiprazole  741  3,287,230  2,464,984  4,109,475  448  100% 
Insulin Detemir  608  3,263,891  2,259,060  4,268,722  330  74% 
Risperidone  912  3,261,673  2,142,436  4,380,909  448  100% 
Lovastatin  407  3,252,884  2,438,753  4,067,016  447  100% 
Tizanidine Hcl  551  3,251,194  2,461,005  4,041,382  448  100% 
Buspirone Hcl  642  3,238,310  2,342,026  4,134,594  448  100% 
Losartan/Hydrochlorothiazide  335  3,163,313  2,330,813  3,995,813  448  100% 
Naproxen  493  3,146,415  2,403,633  3,889,197  448  100% 
Finasteride  480  2,960,782  1,827,731  4,093,833  448  100% 
Budesonide/Formoterol  448  2,954,173  2,211,854  3,696,491  315  70% 
Fumarate 
Alcohol Antiseptic Pads**  274  2,905,342  1,837,210  3,973,474  Supply Item   Supply Item 
Polyethylene Glycol 3350**  908  2,828,333  2,170,778  3,485,888   Excluded  Excluded 
Amitriptyline Hcl  389  2,804,769  1,839,361  3,770,177  448  100% 
Rivaroxaban  444  2,771,551  2,280,525  3,262,578  442  99% 
Azithromycin  530  2,771,301  2,333,713  3,208,888  448  100% 
Spironolactone  470  2,753,760  1,943,293  3,564,227  448  100% 
Tiotropium Bromide  374  2,750,249  2,096,743  3,403,755  322  72% 
Valsartan  394  2,711,004  1,873,134  3,548,874  446  100% 
Paroxetine Hcl  411  2,695,821  1,881,253  3,510,389  448  100% 
Clonidine Hcl  513  2,572,597  1,901,774  3,243,419  448  100% 
Lamotrigine  601  2,565,889  1,611,136  3,520,643  448  100% 
Triamcinolone Acetonide  450  2,424,745  1,787,234  3,062,256  448  100% 
Glimepiride  332  2,319,173  1,483,930  3,154,417  448  100% 
Diazepam  370  2,237,272  1,399,880  3,074,664  448  100% 
Apixaban  522  2,190,255  1,291,509  3,089,002  445  99% 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix C | 25  The 200 drugs with the highest utilization by dual eligibles, continued. 
Generic Name  Sample  Projected  95-Percent Confidence Interval*  Number of  Percentage 
Size*  Drug  Formularies  of 
Events*  Including  Formularies 
Drug  Including 
Lower Bound  Upper Bound  Drug 
Benztropine Mesylate  585  2,181,952  1,524,443  2,839,461  448  100% 
Cephalexin  462  2,168,923  1,808,636  2,529,210  448  100% 
Valsartan/Hydrochlorothiazide  208  2,083,648  1,273,641  2,893,655  445  99% 
Ezetimibe  283  2,080,407  1,434,528  2,726,286  448  100% 
Topiramate  329  2,060,546  1,203,140  2,917,953  448  100% 
Carbamazepine  436  2,042,858  1,335,518  2,750,198  448  100% 
Ciprofloxacin Hcl  440  2,015,783  1,664,815  2,366,751  448  100% 
Lactulose  411  1,992,207  1,187,329  2,797,084  448  100% 
Acetaminophen With Codeine  362  1,981,127  1,254,226  2,708,028  448  100% 
Insulin Lispro  329  1,896,051  1,279,278  2,512,824  205  46% 
Triamterene/Hydrochlorothiazid  185  1,824,876  1,074,026  2,575,725  448  100% 
Propranolol Hcl  323  1,791,767  1,097,354  2,486,179  448  100% 
Fenofibrate  217  1,782,991  1,082,751  2,483,231  447  100% 
Enalapril Maleate  179  1,769,779  905,593  2,633,964  448  100% 
Gemfibrozil  113  1,763,947  1,143,080  2,384,814  448  100% 
Ketoconazole  463  1,760,991  1,353,705  2,168,277  448  100% 
Lidocaine  294  1,694,796  1,212,579  2,177,014  448  100% 
Amoxicillin  354  1,668,610  1,403,958  1,933,263  448  100% 
Pioglitazone Hcl  208  1,667,963  1,269,416  2,066,511  448  100% 
Brimonidine Tartrate  319  1,639,611  1,127,120  2,152,101  448  100% 
Ropinirole Hcl  315  1,631,405  965,956  2,296,854  448  100% 
Chlorthalidone  181  1,604,503  929,770  2,279,237  448  100% 
Temazepam  277  1,601,283  998,072  2,204,494  420  94% 
Linagliptin  322  1,592,388  974,706  2,210,070  353  79% 
Olanzapine  632  1,591,348  1,110,709  2,071,988  448  100% 
Solifenacin Succinate  234  1,568,041  958,484  2,177,597  242  54% 
Amoxicillin/Potassium Clav  314  1,559,156  1,287,885  1,830,427  448  100% 
Digoxin  372  1,557,726  1,113,667  2,001,785  448  100% 
Sulfamethoxazole/Trimethoprim  376  1,556,394  1,296,981  1,815,806  448  100% 
Levofloxacin  344  1,537,701  1,287,012  1,788,389  448  100% 
Dorzolamide Hcl/Timolol Maleat  172  1,422,922  746,389  2,099,456  448  100% 
Dexlansoprazole  253  1,421,606  1,126,083  1,717,130  235  52% 
Verapamil Hcl  139  1,407,301  702,478  2,112,124  448  100% 
Meclizine Hcl  266  1,385,985  1,066,354  1,705,615  448  100% 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix C | 26  The 200 drugs with the highest utilization by dual eligibles, continued. 
Generic Name  Sample  Projected  95-Percent Confidence Interval*  Number of  Percentage 
Size*  Drug  Formularies  of 
Events*  Including  Formularies 
Drug  Including 
Lower Bound  Upper Bound  Drug 
Promethazine Hcl  356  1,374,089  901,853  1,846,325  445  99% 
Celecoxib  260  1,373,116  1,003,862  1,742,370  424  95% 
Sucralfate  287  1,338,530  868,210  1,808,851  448  100% 
Nifedipine  209  1,333,977  866,495  1,801,460  443  99% 
Cyclosporine  192  1,321,576  829,261  1,813,891  448  100% 
Nitroglycerin  247  1,311,819  1,007,730  1,615,907  448  100% 
Olopatadine Hcl  271  1,309,908  846,997  1,772,819  429  96% 
Carbidopa/Levodopa  376  1,294,425  545,138  2,043,711  448  100% 
Bimatoprost  190  1,286,227  946,896  1,625,559  427  95% 
Fluticasone/Vilanterol  225  1,257,029  873,110  1,640,948  420  94% 
Fenofibrate Nanocrystallized  196  1,251,598  723,275  1,779,920  441  98% 
Fentanyl  281  1,248,854  627,928  1,869,779  448  100% 
Bumetanide  203  1,235,654  573,161  1,898,148  448  100% 
Phenytoin Sodium Extended  201  1,226,893  685,081  1,768,704  448  100% 
Ondansetron Hcl  297  1,226,258  906,182  1,546,334  448  100% 
Benazepril Hcl  154  1,211,933  660,106  1,763,760  447  100% 
Morphine Sulfate  333  1,206,063  751,687  1,660,439  448  100% 
Methylprednisolone  199  1,203,903  1,018,121  1,389,686  448  100% 
Doxycycline Hyclate  279  1,201,848  906,926  1,496,770  448  100% 
Ergocalciferol (Vitamin D2)**  189  1,200,330  596,167  1,804,493   Excluded   Excluded 
Dicyclomine Hcl  168  1,159,216  618,650  1,699,783  448  100% 
Fluconazole  210  1,153,890  753,047  1,554,733  448  100% 
Calcitriol  175  1,148,149  612,607  1,683,691  448  100% 
Doxepin Hcl  181  1,144,832  635,462  1,654,202  448  100% 
Ramipril  130  1,142,590  584,408  1,700,772  448  100% 
Ziprasidone Hcl  222  1,123,534  531,199  1,715,869  448  100% 
Omega-3 Acid Ethyl Esters  139  1,119,997  764,858  1,475,135  344  77% 
Linaclotide  246  1,090,286  777,467  1,403,104  422  94% 
Timolol Maleate  184  1,083,472  671,116  1,495,828  448  100% 
Clozapine  330  1,034,103  382,927  1,685,279  448  100% 
Lurasidone Hcl  261  1,024,610  570,101  1,479,119  448  100% 
Ipratropium Bromide  196  1,021,067  570,571  1,471,563  448  100% 
Torsemide  202  1,015,661  534,031  1,497,290  433  97% 
Doxazosin Mesylate  119  1,000,405  520,599  1,480,211  448  100% 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix C | 27  The 200 drugs with the highest utilization by dual eligibles, continued. 
Generic Name  Sample  Projected  95-Percent Confidence Interval*  Number of  Percentage 
Size*  Drug  Formularies  of 
Events*  Including  Formularies 
Drug  Including 
Lower Bound  Upper Bound  Drug 
Amiodarone Hcl  212  976,206  463,364  1,489,049  448  100% 
Haloperidol  205  957,307  472,576  1,442,039  448  100% 
Canagliflozin  101  949,529  471,952  1,427,107  261  58% 
Hydrocortisone  239  945,236  676,889  1,213,583  448  100% 
Dextroamphetamine/Amphetamine  181  943,299  345,815  1,540,783  448  100% 
elviteg/cob/emtri/tenof alafen**  169  929,383  -188,460  2,047,226  Excluded   Excluded  
Lubiprostone  204  924,910  414,901  1,434,918  347  77% 
Amlodipine Besylate/Benazepril  160  924,647  523,690  1,325,604  434  97% 
Tolterodine Tartrate  168  910,574  613,074  1,208,073  433  97% 
Prednisolone Acetate  136  908,681  672,083  1,145,279  448  100% 
Folic Acid**  158  908,345  422,315  1,394,376   Excluded   Excluded 
Ipratropium/Albuterol Sulfate  292  907,850  635,783  1,179,918  433  97% 
Insulin Degludec  97  904,496  157,185  1,651,807  343  77% 
Valacyclovir Hcl  127  893,860  335,040  1,452,681  448  100% 
Clobetasol Propionate  216  887,582  407,481  1,367,684  345  77% 
Umeclidinium Bromide  113  874,194  285,404  1,462,984  342  76% 
Clindamycin Hcl  145  839,832  684,231  995,434  448  100% 
Tacrolimus  73  835,964  575,871  1,096,058  448  100% 
Fluvoxamine Maleate  193  834,436  203,536  1,465,336  448  100% 
Adalimumab  93  830,593  442,227  1,218,960  448  100% 
Valproic Acid  53  821,974  616,774  1,027,173  448  100% 
Mupirocin  212  805,700  576,692  1,034,708  448  100% 
Lithium Carbonate  200  801,133  247,245  1,355,021  448  100% 
Brimonidine Tartrate/Timolol  185  797,031  500,453  1,093,609  411  92% 
Oxcarbazepine  247  795,983  438,599  1,153,368  448  100% 
Colchicine  118  770,523  369,814  1,171,232  448  100% 
Metoclopramide Hcl  159  770,150  437,879  1,102,421  448  100% 
Insulin Regular, Human  132  767,711  405,593  1,129,829  448  100% 
Ranolazine  107  767,060  262,796  1,271,324  448  100% 
Metolazone  129  761,836  316,141  1,207,530  406  91% 
Sitagliptin Phos/Metformin Hcl  113  760,918  327,297  1,194,539  428  96% 
Fluocinonide  153  756,816  250,866  1,262,766  442  99% 
Mirabegron  105  746,707  259,499  1,233,916  447  100% 
Ammonium Lactate  150  740,771  356,666  1,124,875  439  98% 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix C | 28   
The 200 drugs with the highest utilization by dual eligibles, continued. 
Generic Name  Sample  Projected  95-Percent Confidence Interval*  Number of  Percentage 
Size*  Drug  Formularies  of 
Events*  Including  Formularies 
Drug  Including 
Lower Bound  Upper Bound 
Drug 
Paliperidone  124  733,149  566,608  899,690  448  100% 
Metronidazole  160  729,510  513,216  945,805  448  100% 
Travoprost  213  727,589  435,398  1,019,780  397  89% 
Source: OIG analysis of drugs commonly used by dual eligibles, 2020.   
**See Appendix D.
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix C | 29   
APPENDIX D 
 
Five drugs commonly used by dual eligibles were excluded from 
this analysis 
In 2020, five drugs commonly used by dual eligibles were excluded from this 
analysis. 
Generic Name  Reason Excluded From Analysis 
Alcohol antiseptic pads  Supply covered by Part D 
Polyethylene glycol 3350  Nonprescription drug not covered 
under Part D 
Ergocalciferol (vitamin D2)  Vitamin or mineral product not 
covered under Part D 
Elviteg/cob/emtri/tenof alafen  Unable to confidently project use to 
entire dual eligible population 
Folic acid  Vitamin or mineral product not 
covered under Part D 
Source: OIG analysis of formulary inclusion of drugs commonly used by dual eligibles, 2020.
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix D | 30  APPENDIX E 
 
Rates at which prescription drug plan formularies associated 
with stand-alone or Medicare Advantage plans include 
commonly used drugs, by region  
Inclusion of commonly used drugs by formularies associated with stand-alone 
plans, by PDP region 
Across all 34 PDP regions, the rates of formularies inclusion of commonly used drugs 
ranged from 89 percent to 100 percent.  The average range of inclusion was 
96 percent for all PDP regions, except for the New York region, which averaged 
97 percent.  
Inclusion of commonly used drugs by formularies associated with Medicare 
Advantage plans, by MA-PD region 
Exhibit E-1: MA-PD formularies inclusion of commonly used drugs, by MA-PD region. 
MA-PD  State(s)  Number  Average Rate  Minimum  Maximum 
Region*  of  of Drug  Rate  Rate 
 MA-PDs  Inclusion by 
Formularies 
1  Maine, New Hampshire  69  98%  96%  98% 
2  Connecticut, Massachusetts,  125  98%  93%  99% 
Rhode Island, Vermont 
3  New York  218  97%  93%  98% 
4  New Jersey  64  97%  90%  99% 
5  Delaware, the District of  44  98%  97%  99% 
Columbia, Maryland 
6  Pennsylvania, West Virginia  202  98%  93%  100% 
7  North Carolina, Virginia  186  98%  94%  99% 
8  Georgia, South Carolina  180  98%  96%  99% 
9  Florida  448  98%  90%  100% 
10  Alabama, Tennessee  148  98%  96%  99% 
11  Michigan  94  98%  96%  99% 
12  Ohio  154  98%  93%  99% 
13  Indiana, Kentucky  147  98%  96%  99% 
 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix E | 31  MA-PD formularies inclusion of commonly used drugs, by MA-PD region, continued. 
MA-PD  State(s)  Number  Average Rate  Minimum  Maximum 
Region*  of  of Drug  Rate  Rate 
 MA-PDs  Inclusion by 
Formularies 
14  Illinois, Wisconsin  206  98%  90%  100% 
15  Arkansas, Missouri  130  98%  96%  99% 
16  Louisiana, Mississippi  98  98%  96%  99% 
17  Texas  199  98%  93%  99% 
18  Kansas, Oklahoma  86  98%  96%  99% 
19  Iowa, Minnesota, Montana,  140  98%  90%  99% 
Nebraska, North Dakota, 
South Dakota, Wyoming 
20  Colorado, New Mexico  89  98%  93%  99% 
21  Arizona  99  98%  96%  99% 
22  Nevada  45  98%  93%  99% 
23  Idaho, Oregon, Utah,  255  98%  93%  99% 
Washington 
24  California  374  98%  94%  99% 
25  Hawaii  23  98%  96%  99% 
Source: OIG analysis of formularies inclusion of drugs commonly used by dual eligibles, 2020. 
* Region 26, which covers Alaska, had no MA-PDs available for 2020. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Appendix E | 32   
ACKNOWLEDGMENTS AND CONTACT 
 
Acknowledgments 
Lisa Minich served as the team leader for this study, and Jonathan Carroll served as 
the lead analyst.  Office of Evaluation and Inspections staff who provided support 
include Joe Chiarenzelli, Kevin Farber, and Frank Rogers.  
This report was prepared under the direction of Laura Kordish, Regional Inspector 
General for Evaluation and Inspections in the Chicago regional office, and Kelly 
Waldhoff and Adam Freeman, Deputy Regional Inspectors General. 
Contact 
To obtain additional information concerning this report, contact the Office of Public 
Affairs at Public.Affairs@oig.hhs.gov.  OIG reports and other information can be found 
on the OIG website at oig.hhs.gov. 
Office of Inspector General 
U.S. Department of Health and Human Services 
330 Independence Avenue, SW 
Washington, DC 20201 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Acknowledgments and Contact | 33   
ABOUT THE OFFICE OF INSPECTOR GENERAL 
 
 
The mission of the Office of Inspector General (OIG), as mandated by Public Law 95-
452, as amended, is to protect the integrity of the Department of Health and Human 
Services (HHS) programs, as well as the health and welfare of beneficiaries served by 
those programs.  This statutory mission is carried out through a nationwide network 
of audits, investigations, and inspections conducted by the following operating 
components: 
The Office of Audit Services (OAS) provides auditing services for HHS, 
either by conducting audits with its own audit resources or by overseeing audit work 
done by others.  Audits examine the performance of HHS programs and/or its 
grantees and contractors in carrying out their respective responsibilities and are 
intended to provide independent assessments of HHS programs and operations.  
These audits help reduce waste, abuse, and mismanagement and promote economy 
and efficiency throughout HHS. 
The Office of Evaluation and Inspections (OEI) conducts national 
evaluations to provide HHS, Congress, and the public with timely, useful, and reliable 
information on significant issues.  These evaluations focus on preventing fraud, waste, 
or abuse and promoting economy, efficiency, and effectiveness of departmental 
programs.  To promote impact, OEI reports also present practical recommendations 
for improving program operations. 
The Office of Investigations (OI) conducts criminal, civil, and administrative 
investigations of fraud and misconduct related to HHS programs, operations, and 
beneficiaries.  With investigators working in all 50 States and the District of Columbia, 
OI utilizes its resources by actively coordinating with the Department of Justice and 
other Federal, State, and local law enforcement authorities.  The investigative efforts 
of OI often lead to criminal convictions, administrative sanctions, and/or civil 
monetary penalties. 
The Office of Counsel to the Inspector General (OCIG) provides 
general legal services to OIG, rendering advice and opinions on HHS programs and 
operations and providing all legal support for OIGs internal operations.  OCIG 
represents OIG in all civil and administrative fraud and abuse cases involving HHS 
programs, including False Claims Act, program exclusion, and civil monetary penalty 
cases.  In connection with these cases, OCIG also negotiates and monitors corporate 
integrity agreements.  OCIG renders advisory opinions, issues compliance program 
guidance, publishes fraud alerts, and provides other guidance to the health care 
industry concerning the anti-kickback statute and other OIG enforcement authorities. 
Part D Plans Generally Include Drugs Commonly Used by Dual Eligibles: 2020 
OEI-05-20-00190  Endnotes | 34