How to compare and join a Medicare drug plan, step by step

Updated 2026-10-18 · Reviewed for accuracy by the EKO Labs team. Educational only; not medical advice.

Medicare Open Enrollment runs every year from October 15 to December 7, and it is the time many people review or change their Medicare drug coverage. This guide walks through the steps Medicare.gov describes for comparing and joining a plan. It is general information, not medical or insurance advice, and it does not recommend any plan.

Who can join a Medicare drug plan?

According to Medicare.gov, to join a Medicare health plan or drug plan you generally must:

• have Medicare Part A and/or Part B (you need either one to join a Medicare drug plan, and both to join a Medicare Advantage Plan);
• be a U.S. citizen or U.S. national, a lawful permanent resident (green card holder), a Cuban-Haitian entrant, or lawfully living in the U.S. as a Compact of Free Association (COFA) migrant;
• live in the service area of the plan you want to join;
• have your Medicare Number and your Part A and/or Part B start dates, which are on your Medicare card.

When can you join, switch or drop a plan?

You can only join, switch or drop a plan during certain enrollment periods. The main ones listed by Medicare.gov are:

• Initial Enrollment Period: generally when you turn 65. It lasts 7 months, starting 3 months before you turn 65 and ending 3 months after the month you turn 65.
• Open Enrollment Period, October 15 to December 7: you can join, drop or switch a Medicare Advantage Plan, and join, drop or switch a Medicare drug plan if you have Original Medicare. Coverage starts January 1 of the next year, and the plan must get your request by December 7.
• Medicare Advantage Open Enrollment, January 1 to March 31: only if you are already in a Medicare Advantage Plan.
• Special Enrollment Period: only for certain situations, such as moving to a new address, losing or changing your current coverage, getting Medicaid, or getting Extra Help to pay drug costs.

Step 1: find the plans available where you live

Medicare.gov lists several ways to see the plans in your area:

• use the Medicare Plan Finder at Medicare.gov/plan-compare to see what each plan costs and which services it provides;
• add every prescription drug you take regularly, so the tool can estimate your monthly and yearly cost for each plan;
• look in the back of your "Medicare & You" handbook, where plans are listed;
• talk to a trusted agent or broker (Medicare.gov says to check the rules they must follow);
• contact your State Health Insurance Assistance Program (SHIP) for free, personalized counseling. SHIPs are not connected to any insurance company or health plan.

Step 2: make sure the plan fits your needs

• Check that the plan covers your prescriptions and includes the benefits you need. Our guide on drug formularies explains tiers and coverage rules.
• Ask your doctors and pharmacies whether they are in network with the plan.
• Review the costs: monthly premium, deductible and the estimate of your yearly drug costs. Medicare.gov notes that no Medicare drug plan may have a deductible of more than $615 in 2026 ($700 in 2027).
• If you have other health insurance or drug coverage, talk to your benefits administrator or insurer before you join a plan or change your current coverage.
• If you live in another state for part of the year, check whether the plan covers you there.

Step 3: join the plan

Medicare.gov says there are three ways to join once you have chosen a plan:

• select "Enroll" for the plan you want at Medicare.gov/plan-compare;
• contact the plan directly, by phone or on its website. You can also ask for a paper form to fill out and mail back, but the plan must receive it before your enrollment period ends;
• call 1-800-MEDICARE (1-800-633-4227). TTY users can call 1-877-486-2048.

What to know about timing and your Medicare Number

Keep your Medicare Number and your coverage start dates handy before you apply. If you request to join after your Part A and/or Part B has started, Medicare.gov says your plan coverage generally starts on the first of the month after the plan gets your request. For the Open Enrollment Period, coverage starts January 1.

Do not wait too long

Medicare.gov advises considering a drug plan with a low monthly premium even if you take few drugs now, so you can avoid the Part D late enrollment penalty. Our Part D guide explains how the penalty works.

Questions to ask before you join

• Are all of my medicines on this plan's drug list, and in which tier?
• Does the plan require prior authorization or step therapy for any of them?
• Is my pharmacy in the plan's network, and is mail-order available?
• What would my yearly drug cost be, according to the Plan Finder?

EKO Labs does not sell insurance or recommend plans. Our team can help you prepare questions in Portuguese or English by phone. EKO Labs does not publish dosing instructions.

Sources: Medicare.gov, "Joining a plan" (medicare.gov/basics/get-started-with-medicare/get-more-coverage/joining-a-plan) and "How much does Medicare drug coverage cost?" (medicare.gov/health-drug-plans/part-d/basics/costs), consulted October 2026. This guide is general information, not medical or insurance advice.