Investopedia research found that Humana and Aetna are tied for the best Medicare Part D providers, with Humana offering more gap coverage and Aetna excelling at low premiums.
Medicare Part D is optional prescription drug coverage available to those with Medicare Part A and/or Part B as a standalone plan. While most Medicare Advantage (MA) providers include Part D drug benefits in their package, if you want drug coverage without joining an MA plan, you may want to get a Part D plan. (Note that with most MA plans, you can't buy a Part D plan, even if your MA plan has no drug benefits.)
To determine the best Medicare Part D providers, we considered state availability, company financial strength, third-party ratings, including Medicare star ratings and those from the National Committee for Quality Assurance (NCQA), an independent organization that measures health plan quality and patient satisfaction.
We also looked at average premiums, deductibles, copays, out-of-pocket expenses, and drug coverage during the “gap” or “donut hole.” The Medicare donut hole is a phase of reduced insurance coverage that you enter once you and your Medicare prescription drug plan have spent $5,030 on covered drug costs in 2024. Then, you have to cover up to 25% of drug costs out of pocket until you’ve spent $8,000. Coverage during the gap can significantly lower your costs.
Best Medicare Part D Plans
- Best Overall and Best for Additional Drug Coverage in the Gap: Humana
- Best Overall and Best for Low Costs: Aetna
- Best for Customer Satisfaction: AARP/UnitedHealthcare
- Great for $0 Copays: Cigna
To avoid a late enrollment penalty, Part D coverage must be purchased within nine months of initial enrollment eligibility or five months after you turn 65, unless you have coverage from another source.
Best Overall and Best for Additional Drug Coverage in the Gap : Humana
![Humana](https://www.investopedia.com/thmb/jgGWkah4OUz3ML9O22zPk1F6B9k=/fit-in/1500x1000/filters:format(png):fill(white):max_bytes(150000):strip_icc()/Humana-a8ab66cb32b54e64ad3af1fe384a2c68.jpg)
Humana
- AM Best financial strength rating: A- (Excellent)
- Copays and deductibles: $0 copays and deductibles on tier 1 and 2 drugs on the Walmart Value and Premier plans
- Extras: If you use Humana’s CenterWell Pharmacy, you may benefit from lower copays on most medications
Humana offers the most comprehensive coverage for prescription medications, with multiple plans providing additional coverage for select drug tiers during the gap coverage phase.
"Many drug plans offer additional benefits to help manage prescription costs during the donut hole gap phase, such as reduced copayment or coinsurance requirements. If you want continued access to your medication at the most affordable rate, making sure your plan provides additional coverage in the gap is crucial."
— Shanker Narayan, Investopedia Research Analyst
Offers multiple plans with additional gap coverage
Low-cost plans available with $0 deductibles and copays for many generic and brand-name drugs
Plans available in all 50 states and Washington, D.C.
Pharmacy network may be limited in some areas
Humana’s Walmart Value Rx Plan includes gap coverage for tier 1 and tier 2 medications, while the Premier Rx plan includes gap coverage for tiers 1, 2, and 6. While Humana’s plans are more expensive than competitor plans on average, they may be a better value for folks who spend enough on prescription generic and name-brand drugs to enter the gap coverage phase.
Humana offers $0 copays on mail-order prescriptions with some plans. If you plan to pick up your prescriptions in-store, ensure you have access to pharmacies in Humana’s preferred pharmacy network before enrolling. They include Walmart, Sam’s Club, Publix, H-E-B, Costco, and Albertsons. Prescriptions outside this network are more costly.
Read more in our Humana Medicare review.
Best Overall and Best for Low Costs : Aetna
![Aetna](https://www.investopedia.com/thmb/izoRq1YOHhvJ2RbU2VUPIqVjL2g=/fit-in/1500x1000/filters:format(png):fill(white):max_bytes(150000):strip_icc()/Aetna-3bac774a8339456ca4f01fde76bdbbf0.jpg)
Aetna
- AM Best financial strength rating: A (Excellent)
- Copays and deductibles: Choose a low premium and higher copays or vice versa
- Extras: Free prescription delivery and 100-day supplies at no extra cost; new Aetna Medicare SmartFit plans offer $600-$1,200 annually for activities like pickleball
Aetna’s plans offer the best value for 2024 based on premiums and deductibles, and the company’s SilverScript Plus plan provides additional coverage during the gap phase. Aetna’s cheapest plan also offers the lowest premium of any provider for the states we reviewed.
Offers the best value of all PDP providers when considering premiums and deductibles
Offers free prescription home delivery
Additional drug coverage during the Medicare donut hole
Only one plan provides coverage during the Medicare donut hole period
Expensive copays/coinsurance if you take non-generic medications (tiers 3-5) on some plans
Whether you’re looking for a cheap plan “just in case” or you spend a lot of money on generics each year, Aetna’s prescription drug plans may be a good fit. Along with providing cheap premiums, Aetna is ranked better than average by the NCQA and has the highest average CMS star rating of major Medicare Plan D providers.
Aetna offers three SilverScript plans. You can choose a low premium and higher copays or vice versa. The SmartSaver plan has an average monthly premium of $11.19, but it also has the highest copays. The SilverScript Plus plan’s $103.51 premium is almost 10 times the SmartSaver plan’s. But SilverScript Plus has a $0 deductible and more $0 copays, including during the coverage gap. The SilverScript Choice plan offers a compromise between the two.
Coverage is available nationwide.
Learn more in our Aetna Medicare review.
Best for Customer Satisfaction : AARP/UnitedHealthcare
![AARP](https://www.investopedia.com/thmb/CRAEaQ8wlEbGxoWulxQ__B0CWFE=/fit-in/1500x1000/filters:format(png):fill(white):max_bytes(150000):strip_icc()/AARP-838353bfd2de4de994bc33c06d352c0b.jpg)
AARP
- AM Best financial strength rating: A+ (Superior)
- Copays and deductibles: $0-$7 copays and a $0 deductible option
- Extras: Free delivery on 90-day supplies
UnitedHealthcare has the highest average NCQA rating of major Medicare providers, along with the highest financial strength with AM Best.
High average NCQA rating relative to other companies
High financial strength ratings
$0 deductible options
Plans either offer a broad pharmacy network or cheap fills at Walgreens
Highest national average premium
UnitedHealthcare has strong quality and consumer satisfaction ratings, with an average rating of 3.9 out of 5 stars from the NCQA—the highest rating among companies we reviewed. NCQA ratings incorporate member satisfaction as well as plan quality metrics. UHC also earned an above-average Medicare (CMS) star rating of 3.2 for the performance of its prescription drug plans.
Other strong third-party ratings include an A+ (Superior) financial strength rating from AM Best. An A+ rating indicates that UnitedHealthcare offers “a superior ability” to meet ongoing insurance obligations to policyholders.
UnitedHealthcare’s AARP MedicareRx Walgreens plan is a good option if you rely on generics and have access to a Walgreens pharmacy. It offers a low premium with $2 copays and no deductible on preferred tier 1 drugs purchased from Walgreens. The company’s other plans offer a broader pharmacy network.
UnitedHealthcare is also our pick for the best Medicare Advantage plan and best Medicare Supplement (Medigap) plan. UHC offers coverage throughout the United States and in Washington, D.C.
Read more in our UnitedHealthcare Medicare review.
UnitedHealthcare Group is being sued for allegedly using a flawed artificial intelligence algorithm that denies rehabilitation care for Medicare Advantage patients, despite knowing that the algorithm has a 90% error rate.
Great for $0 Copays : Cigna
![Cigna](https://www.investopedia.com/thmb/lkwQm-uEf9TzRV42imtx9xPPHaA=/fit-in/1500x1000/filters:format(png):fill(white):max_bytes(150000):strip_icc()/Cigna-378d268f43e347a19ce406202f187a19.jpg)
Cigna
- AM Best financial strength rating: A (Excellent)
- Copays and deductibles: Low or $0 copays and deductibles on most generics
- Extras: Free home delivery for 90-day supplies of many prescription drugs
Cigna offers three plans to choose from. Premiums are relatively low on average, and each plan provides low or $0 copays on most generics and a $0 deductible for most generics.
Low or $0 copays and deductibles for many generic medications
A plan option with additional drug coverage in the Medicare gap
Comes with discounts on certain non-covered services
Lower NCQA and Medicare star ratings than competitors
Two Cigna plans offer an option for a $0 copay for tier 1 generics at preferred pharmacies or by mail order. Two options provide a $0 deductible for generics as well. Cigna also offers additional coverage for tier 1 and tier 2 generics during the gap phase. Always check plan costs for your specific drugs, as each insurance company’s formulary differs.
Cigna’s plans also come with perks, like discounts on LASIK, Gaiam yoga products, and acupuncture, and most medications are available in a 90-day supply with free home delivery. Cigna PDPs are available in all 50 states.
For more information, read our full Cigna Medicare review.
Bottom Line
The best plan for you depends on your prescriptions and which pharmacies are most convenient. Aetna is likely the best choice if you take few or no prescription medications because its premiums and deductibles are low, but when you do buy medications, you may pay more at the register.
Humana will likely be your best bet if you’re looking for the most comprehensive coverage, including gap coverage. If you take a lot of generic medications, Cigna is a good option for low copays, and one plan covers generics during the gap phase. If you’re looking to pick up your prescription at Walgreens or access an extensive pharmacy network, or if you want to choose a company with high third-party ratings, UnitedHealthcare fits the bill.
Research Insight
"With many types of insurance, if you have a higher deductible, your premium is lower. But prescription drug plans don’t always follow that pattern. Two plans with the same drug deductible could have different premium amounts. When choosing a plan, be sure to investigate all costs, including out-of-pocket expenses, such as copays and coinsurance."
— Shanker Narayan, Investopedia Research Analyst
Frequently Asked Questions
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What Is Medicare Part D?
Medicare Part D is offered by commercial insurance companies to people who have Original Medicare. Part D pays for your prescription medications. All plans cover various common prescriptions. Each formulary’s tiers determine how much you’ll pay for different prescriptions. Generic prescriptions are typically in a lower tier and are less costly than brand-name drugs.
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How Much Is Medicare Part D?
The projected average monthly premium for a Medicare Part D plan is expected to decrease to $55.50 in 2024, but plans are available for much less. Aetna’s SilverScript SmartSaver PDP costs an average of $11.19 monthly, though your premium may vary. You must pay your deductible before coverage kicks in, and you’ll pay prescription copays and coinsurance costs. These differ widely depending on the company and plan, so shop around. Plans with higher premiums typically have lower copays and deductibles, and vice versa.
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What Is the Medicare Donut Hole or Coverage Gap?
The Medicare donut hole is a phase of reduced insurance coverage that you enter once you and your Medicare prescription drug plan have spent $5,030 on drug costs in 2024. Then, you have to cover up to 25% of generic and brand-name drug costs out of pocket. For 2024, you’ll leave the coverage gap once you’ve spent $8,000 out of pocket. That’s when you enter the catastrophic coverage phase, during which you’ll pay a significantly lower copay or coinsurance for the rest of the year.
Some Medicare Part D plans offer additional coverage during the gap phase, which can greatly reduce costs. In 2025, the coverage gap phase won’t exist anymore.
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What Does Medicare Part D Cover?
Your Medicare Part D prescription drug plan covers medications in your insurance company’s formulary. The formulary is a list of covered drugs that can change over time, and at any time. Medications are categorized between four to six tiers, often covered at different percentages or with various copays by tier. Medicare Part D plans typically cover generic, name-brand, and specialty medications.
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Is Medicare Part D Worth Having?
The average PDP premium for 2024 is expected to be $55.50 a month, so carrying Part D insurance shouldn't be a huge backbreaker for many people. Those living on benefits or thin retirement savings might still find it a bit expensive, but a low-income subsidy plan expands in 2024 to help defray some of that cost. You could pay much more for your overall prescription costs if you forgo coverage. The late enrollment penalty could kick in if you sign up for a plan later, and you might have to cover your drug costs until open enrollment.
Big changes are coming for Medicare beneficiaries in the coming years, thanks to the Inflation Reduction Act. There will be no coinsurance in the catastrophic phase starting in 2024, and a $2,000 out-of-pocket spending cap will be added for drug coverage in 2025.
How We Chose the Best Medicare Part D Providers
To identify which health insurance companies to review, we analyzed business and market insight databases including Statistia, Plunkett, and Gale. We also considered user-generated data from Google to determine public interest and trends in Medicare plans.
We collected data from third-party rating agencies like the credit rating agency AM Best and the National Committee for Quality Assurance (NCQA), an independent organization that rates health insurance plans on quality and customer satisfaction. We also gathered data from government websites and databases provided by the Centers for Medicare and Medicaid Services (CMS) such as CMS.gov and HealthCare.gov, and directly from companies via websites, media contacts, and existing partnerships. The data collection process spanned Sept. 15 to Sept. 29, 2023.
We then developed a quantitative model that scores each Medicare Part D provider based on five major categories and 17 criteria that are crucial in evaluating the company's offerings and benefits.
We weighted the five categories as follows for this article:
- Plan quality and customer satisfaction: 30%
- Plan features (coverage in the gap): 25%
- Cost: 20%
- Availability: 15%
- Company financial strength: 10%
Read our full methodology for reviewing Medicare insurance providers.
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