Medicare Enrollment Checklist for 2026
By Tyler Dalton, PharmD, Licensed Medicare Agent Published Updated
Medicare enrollment runs on fixed windows, and missing one can raise your premiums for life. Your Initial Enrollment Period lasts 7 months around your 65th birthday, and this checklist walks through exactly what to do before, during, and after that window so nothing slips.
Why deadlines matter more than plan choice
You can change a Medicare plan you do not like. You usually cannot undo a late-enrollment penalty. The Part B penalty adds 10% of the standard premium for every full year you were late, permanently. At 2026's standard premium of $202.90 per month, a two-year delay costs an extra $40.58 every month for the rest of your life. The Part D drug penalty works the same way at 1% per month late. Roughly one in five people misses at least one window, almost always because they assumed something counted as coverage that did not.
Your enrollment timeline at a glance
| Window | When | What it is for |
|---|---|---|
| Initial Enrollment Period | 3 months before your 65th birthday month, your birthday month, and 3 months after | First sign-up for Parts A and B; enroll early in the window for on-time coverage |
| Medigap Open Enrollment | 6 months from the day you are 65+ and have Part B | Buy any Medigap plan with no health questions |
| Annual Enrollment Period | October 15 to December 7 | Switch Advantage or Part D plans for January 1 |
| MA Open Enrollment | January 1 to March 31 | One switch out of a Medicare Advantage plan you regret |
| General Enrollment Period | January 1 to March 31 | Catch-up window if you missed your IEP; penalties may apply |
| Special Enrollment Periods | Event-based | Leaving employer coverage, moving, and other qualifying events |
The checklist
6 to 12 months before 65
- Confirm your Social Security earnings record at ssa.gov; 40 quarters of covered work makes Part A premium-free.
- Decide how your current insurance interacts with Medicare. If you will keep working past 65, ask HR one question in writing: does this employer have 20 or more employees?
- Start a simple file: doctors you will not give up, prescriptions with dosages, and your preferred pharmacy.
3 months before your birthday month
- Apply for Medicare online at ssa.gov, by phone, or at a Social Security office. If you already draw Social Security, enrollment in A and B is automatic and your card arrives by mail.
- Choose your path: Original Medicare plus a Medigap plan and Part D drug plan, or a Medicare Advantage plan that bundles everything. The side-by-side comparison explains the tradeoffs.
- Run your drug list through the plans you are considering. This is the single highest-value step and the one most people skip.
Your birthday month
- Verify your Part A and B effective dates on your Medicare card.
- If you chose Original Medicare, submit your Medigap and Part D applications so all coverage starts together.
- If you are not drawing Social Security yet, expect a quarterly premium bill for Part B; set up Medicare Easy Pay so a missed invoice never cancels your coverage.
After coverage starts
- Give your new card details to every doctor's office and your pharmacy.
- Book your free Welcome to Medicare visit within the first 12 months.
- Calendar October 15: plans change premiums, drug lists, and networks every year, and an annual review catches it.
Get the checklist by email
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Alabama notes
Alabama follows the federal windows above with no extra state-level Medigap enrollment rights, so the 6-month Medigap window matters more here than in states with birthday rules. If you want free unbiased counseling in addition to an agent, Alabama SHIP through the Alabama Department of Senior Services offers it at 1-800-243-5463. And if you live near our office, the Alabama Medicare guide and our Dadeville and Lake Martin page cover what is available locally.
Frequently asked questions
- When exactly can I first enroll in Medicare?
- Your Initial Enrollment Period lasts 7 months: the 3 months before your 65th birthday month, your birthday month, and the 3 months after. Enrolling in the 3 months before your birthday month gives you coverage that starts the month you turn 65.
- What happens if I miss my enrollment window?
- The Part B late penalty adds 10% of the standard premium for every full 12-month period you delayed, and it lasts for as long as you have Part B. The Part D penalty adds 1% of the national base premium ($38.99 in 2026) for every month you went without creditable drug coverage.
- I am still working at 65. Do I have to enroll?
- If your employer has 20 or more employees and you have coverage through that job, you can usually delay Part B without penalty and enroll later through a Special Enrollment Period. If the employer has fewer than 20 employees, Medicare generally needs to be your primary coverage at 65.
- When can I buy a Medigap plan without health questions?
- Your Medigap open enrollment window lasts 6 months from the day you are both 65 or older and enrolled in Part B. During that window carriers must sell you a policy at their best rate regardless of health history. In Alabama, applying outside that window usually means medical underwriting.
- What is the Annual Enrollment Period?
- October 15 through December 7 each year. You can switch Medicare Advantage plans, move between Original Medicare and Medicare Advantage, and change Part D plans. Changes take effect January 1.
- Is COBRA creditable coverage for Medicare?
- No, and this trips people up. COBRA does not count as employer coverage for delaying Part B. If you retire and take COBRA past 65 without enrolling in Part B, you can face gaps and lifetime penalties.
Want a second set of eyes on your timeline?
Talk through your options with Tyler Dalton, PharmD, Licensed Medicare Agent. Consultations are free, and you keep the final say on every decision.