Medicare Part D —Prescription Drug Coverage
Medicare Part D provides prescription drug coverage for Medicare beneficiaries. Choosing the right plan requires comparing formularies, tier structures, and cost-sharing for your specific medications. We make that comparison simple — and it costs you nothing.
How Medicare Part D Works
Part D plans are offered by private insurance companies approved by Medicare. Each plan has its own list of covered drugs (formulary), cost-sharing structure, and pharmacy network. The right plan for you depends entirely on which medications you take.
Drug formulary. Each plan has a formulary — a list of covered drugs organized into tiers. Generic drugs sit on lower tiers with lower cost-sharing; brand-name and specialty drugs sit on higher tiers with higher cost-sharing.
Tier structure. Most plans have 4 to 6 tiers. Tier 1 (preferred generics) has the lowest copay. Tier 5 or 6 (specialty drugs) can carry significant coinsurance. Your out-of-pocket cost depends on which tier your medications fall on.
Deductible. Many Part D plans have an annual deductible before coverage begins. Some waive it for lower-tier drugs. The maximum is set by CMS each year.
Annual Enrollment Period. Part D plans can be changed between October 15 and December 7 for coverage starting January 1. You can also switch in certain special circumstances during the year.
What drives your Part D costs
- Monthly premium, which varies widely by plan
- Annual deductible, where one applies
- Copay or coinsurance per drug, by tier
- Pharmacy network: preferred vs. standard
- Mail-order vs. retail pricing
- Specialty drug cost-sharing
Key Part D Concepts
Understanding these helps you avoid costly mistakes — like choosing on premium alone, or missing the enrollment window.
Formulary Verification
The single most important step is verifying that all your current medications are on the formulary — and at which tier. We run your complete medication list through each plan before recommending one. Formularies change annually, and prior authorization may apply to some drugs.
Total Annual Cost
Do not choose on premium alone. A plan with a $0 premium may cost significantly more than one with a $40 premium if your medications sit on higher tiers. We calculate your estimated total annual drug cost for each plan.
Preferred Pharmacy Network
Plans designate preferred pharmacies where cost-sharing is lower. Using a preferred pharmacy rather than a standard network one can meaningfully reduce your copays, and mail-order is often the lowest-cost option for maintenance drugs.
Extra Help (LIS)
Low Income Subsidy, also called Extra Help, is a federal program that helps people with limited income and resources pay Part D premiums, deductibles and copays. If you qualify you may pay significantly less. Apply through Social Security.
Coverage Gap Changes
The coverage gap, formerly called the donut hole, has been significantly reduced by the Inflation Reduction Act. Beginning in 2025, out-of-pocket drug costs are capped at $2,000 annually. This materially changes how plans compare.
Annual Review
Formularies, premiums and cost-sharing change every year. A plan that was optimal last year may not be this year, and your medications may move tier. We review during open enrollment to confirm your plan is still the best fit.
Frequently Asked Questions
Do I need Part D if I do not take any medications?
How do I know which Part D plan is best for me?
Can I use any pharmacy with Part D?
What is the Medicare Part D coverage gap?
Does working with a Medicare advisor cost me anything?
We do not offer every plan available in your area. Any information we provide is limited to those plans we do offer in your area. Please contact Medicare.gov or 1–800–MEDICARE to get information on all of your options.
Find the Part D plan with the lowest total cost for your medications.
We run your medication list through every available plan — premium, deductible and copays combined.
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