Medicare Part D

Original Medicare covers some medications in specific clinical settings, including certain drugs administered by a clinician under Part B. It does not provide general retail prescription-drug coverage. Part D covers many outpatient prescriptions that Part A and Part B do not.

A person with Original Medicare can add a standalone Prescription Drug Plan, often shortened to PDP. Most Medicare Advantage plans include Part D; those combined plans are often called MA-PD plans.

See how the pieces connect in the full Medicare guide.

Medicare-approved private insurers contract with the federal government to offer Part D. A carrier such as Cigna may administer a Part D plan, but the underlying benefit is Medicare Part D—not a separate Cigna benefit. Available carriers and plan names depend on location and year.

Medicare sets rules and reviews plan formularies. Within those rules, each plan can have a different premium, deductible, covered-drug list, tier structure, pharmacy network, and utilization-management requirements.

• Formulary: the plan’s list of covered drugs.
• Tier: the cost-sharing category assigned to a drug.
• Pharmacy network: pharmacies contracted with the plan; preferred pharmacies may cost less.
• Prior authorization: approval required before the plan covers a drug.
• Step therapy: trying another covered drug before the plan covers the requested one.
• Quantity limits: limits on how much medication the plan covers at one time.

Compare the exact medication name, dose, frequency, and pharmacy. Two plans with similar premiums can produce very different total costs for the same person.

From October 15 through December 7, someone with Original Medicare can join, drop, or switch a standalone Part D plan for coverage beginning January 1. Medicare Advantage enrollees can choose a plan with different included drug coverage.

Review the plan every fall because it may change:

• the premium or deductible;
• which drugs are covered and on which tiers;
• preferred and in-network pharmacies;
• copays, coinsurance, and coverage restrictions.

The Annual Notice of Change summarizes next year’s changes, but the best comparison uses the complete current medication list in Medicare Plan Compare.

Someone can decline Part D if they have other prescription coverage that Medicare considers creditable—meaning it is expected to pay at least as much as standard Medicare drug coverage. Employer, union, VA, or other coverage should confirm its status in writing.

Going 63 days or more without Part D or other creditable drug coverage after becoming eligible can lead to a late-enrollment penalty when Part D is eventually added. The penalty can continue for as long as the person has Part D.

Extra Help—also called the Low-Income Subsidy or LIS—is a Medicare program for people with limited income and resources. It can lower Part D premiums, deductibles, and prescription costs. People with Medicaid, Supplemental Security Income, or certain Medicare Savings Programs may qualify automatically; others can apply.

Extra Help is not Medigap. Extra Help applies to prescription-drug costs; Medigap supplements Part A and Part B cost sharing under Original Medicare.

• Every medication’s exact name, dose, form, and frequency.
• Whether each drug is covered and on which tier.
• Prior authorization, step therapy, and quantity limits.
• The person’s preferred local and mail-order pharmacies.
• Total estimated annual cost—not only the monthly premium.
• Whether existing employer, union, VA, Medicaid, or Extra Help coverage changes the answer.

Use Medicare Plan Compare with the current medication list, then confirm consequential changes with the plan or a SHIP counselor.