Medicare Part D drug plans: open enrollment guide

Updated 2026-10-08 · Reviewed for accuracy by the EKO Labs team. Educational only; not medical advice.

Medicare drug coverage (Part D) helps pay for prescription medicines. It is optional and is offered by private insurance companies approved by Medicare, either as a stand-alone drug plan or as part of a Medicare Advantage plan. Plans can change their premiums, covered drugs and pharmacies every year, so the yearly Open Enrollment Period is the time to check your plan. This guide is general information, updated in October 2026; Medicare.gov and your plan documents have the exact rules.

When you can join or change a plan

• Initial Enrollment Period: generally when you turn 65. It lasts 7 months: it starts 3 months before the month you turn 65 and ends 3 months after that month.
• Open Enrollment Period: October 15 to December 7 every year. Changes you make take effect on January 1 of the next year.
• Medicare Advantage Open Enrollment Period: January 1 to March 31, only if you are already in a Medicare Advantage plan.
• Special Enrollment Periods: after certain life events, such as moving to a new address, losing or changing other coverage, or getting Medicaid or Extra Help.

What you pay

• Premium: a monthly amount you pay for the coverage, whether or not you fill prescriptions.
• Deductible: what you pay for covered drugs each year before the plan starts to pay. A plan's deductible can be no more than $615 in 2026 and $700 in 2027; some plans have none.
• Copayment or coinsurance: a fixed amount or a percentage you pay at the pharmacy for each prescription.
• Yearly out-of-pocket limit: once your out-of-pocket spending on covered drugs reaches $2,100 in 2026 ($2,400 in 2027), you move to the catastrophic coverage stage and pay nothing more for covered Part D drugs for the rest of that year. Certain payments made for you, such as through Extra Help, count toward this limit.
• Insulin: you pay no more than $35 for a one-month supply of each covered insulinInsulin the hormone that moves sugar from the blood into the body's cells., and you do not have to pay a deductible for it.

Ways to spread out or lower costs

• Medicare Prescription Payment Plan: a payment option that works with your current drug coverage and spreads your out-of-pocket drug costs into monthly payments across the calendar year. It does not lower your total drug costs. Ask your plan how to sign up.
• Extra Help: a Medicare program that helps pay drug costs for people with limited income and resources. You qualify automatically if you have Medicaid, a Medicare Savings Program or Supplemental Security Income (SSI); other people can apply through Social Security.

Avoid the late enrollment penalty

If, after your Initial Enrollment Period ends, you go 63 days or more in a row without Part D or other creditable drug coverage (coverage that is similar in value to Part D, for example from some employer or union plans), you may pay a late enrollment penalty when you join later. It adds 1% of the national base beneficiary premium for each full month you were without coverage, and you pay it for as long as you have Medicare drug coverage, even if you switch plans. Employer and union plans send a yearly notice saying whether their drug coverage is creditable; keep it.

Medicare and GLP-1 medicines for weight management

By law, Medicare drug plans generally do not cover medicines used only for weight loss, although plans may cover GLP-1GLP-1 (glucagon-like peptide-1) a hormone the gut releases after eating. It helps release insulin, slows stomach emptying and signals fullness. medicines for other FDA-approvedFDA-approved the FDA reviewed the medicine's safety and effectiveness for a specific use. uses, such as type 2 diabetes. Medicare.gov now describes a temporary program, the Medicare GLP-1 Bridge: starting July 1, 2026, people with Part D who meet its eligibility rules can get certain GLP-1 medicines (Wegovy®, Zepbound® and Foundayo, in the forms Medicare lists) for a fixed monthly copayment. Eligibility depends on being 18 or older, on body mass index (BMI) and on certain health conditions, and some people are not eligible, for example those who already have GLP-1 coverage through their Part D plan. The prescriber must send the prescription, complete prior authorization when asked and certify that the medicine is used as part of a diet and exercise program. For questions about your eligibility, call 1-800-MEDICARE (1-800-633-4227).

How to compare plans during Open Enrollment

1. Read the Annual Notice of Change your plan sends each fall. It lists next year's changes in costs and covered drugs.
2. Make a list of all your medicines with their generic names and strengths, and the pharmacies you use.
3. Use the Medicare Plan Finder on Medicare.gov to compare plans with your own drug list: premium, deductible, estimated yearly cost and whether a drug needs prior authorization or step therapy.
4. Check that your pharmacies are in the plan's network, including mail-order options.
5. If you switch to another Medicare drug plan, you usually do not need to cancel the old one: joining the new plan generally ends the old coverage when the new coverage starts.

Free help in your language

1-800-MEDICARE (1-800-633-4227; TTY 1-877-486-2048) is available 24 hours a day, 7 days a week, except some federal holidays, and offers free interpreter help in many languages. Your State Health Insurance Assistance Program (SHIP) gives free, unbiased one-on-one counseling about Medicare plans.

Questions to ask before you choose

• Are all my medicines on next year's drug list (formulary), and at what tier?
• Do any of my medicines need prior authorization or step therapy, or have quantity limits?
• What will the premium and deductible be next year?
• Are my pharmacies in the plan's network?
• Can I qualify for Extra Help, and would the Medicare Prescription Payment Plan help me?

At EKO Labs, our team can answer general questions in Portuguese or English by phone. EKO Labs does not sell Medicare plans and does not decide Medicare eligibility or coverage.

Sources: Medicare.gov, Joining a plan (enrollment periods); Medicare.gov, Costs for Medicare drug coverage (2026 and 2027 deductible and out-of-pocket limits, Medicare Prescription Payment Plan, Extra Help); Medicare.gov, Part D late enrollment penalty; Medicare.gov, Insulin coverage; Medicare.gov, Weight loss drugs (Medicare GLP-1 Bridge program). This guide is general information, not legal, financial or medical advice.