Strong Tower Advisors · Printable guide

Medicare at 65 Checklist

Organize enrollment dates, current coverage, doctors, prescriptions, costs and HSA timing before you compare plans. It includes an enrollment timeline by birth month and the official 2026 cost figures.

Part 1: Which enrollment path applies to you?

• Already receiving Social Security or Railroad Retirement benefits? You will generally be enrolled in Parts A and B automatically, and your card arrives about 3 months before your 65th birthday. You can decline Part B if you have qualifying job-based coverage.
• Not yet receiving Social Security? You must sign up yourself through Social Security (ssa.gov or 1-800-772-1213), generally during your Initial Enrollment Period.
• Still working, or covered through a working spouse, with group health coverage from that job? You may be able to delay Part B without a penalty. Ask the employer whether you need Parts A and B when you turn 65, because some plans pay secondary to Medicare. When the job or the coverage ends, whichever comes first, you have an 8-month Special Enrollment Period.
• Covered by COBRA, retiree coverage or a Marketplace plan? None of these counts as current-employment coverage for the Part B Special Enrollment Period. Plan to enroll during your Initial Enrollment Period to avoid a gap and a lifetime penalty.
• Contributing to an HSA? See Part 4 before you enroll in anything, including Part A alone.

Part 2: Enrollment timeline by birth month

Your Initial Enrollment Period (IEP) lasts 7 months: the 3 months before the month you turn 65, your birthday month, and the 3 months after. Coverage always starts on the first of a month. If you sign up for Part B before your birthday month, coverage starts the month you turn 65. If you sign up during your birthday month or the 3 months after, coverage starts the month after you sign up.

Premium-free Part A starts the month you turn 65. If you sign up for premium-free Part A after 65, coverage can be backdated up to 6 months, but not earlier than the month you turned 65.

Other enrollment windows to know

Part 3: Information to gather before comparing coverage

12 months before 65

• Create or log in to your my Social Security account and confirm your Medicare eligibility date.
• Ask your employer, or your spouse's employer, how their plan works with Medicare, and get the answer in writing.
• Ask each current drug plan for its creditable-coverage notice and keep it on file.
• Note your 2024 MAGI from your tax return; it sets any 2026 income-related premium (IRMAA).
• If you have an HSA, set the date to stop contributions (Part 4).

6 months before

• List every doctor, specialist and hospital system you want to keep.
• List every prescription with its dosage, plus your preferred pharmacy.
• Note travel patterns, such as spending winters out of state, that affect network needs.
• Understand the two main paths: Original Medicare (Parts A and B), usually with a Part D drug plan and possibly a Medigap policy, or a Medicare Advantage (Part C) plan.
• Set a monthly premium budget and an annual out-of-pocket budget.

3 months before (IEP opens)

• Enroll in Part A and Part B, or confirm automatic enrollment, unless you are delaying Part B based on current-employment coverage.
• Use the Medicare.gov Plan Finder with your drug list to compare drug and Medicare Advantage plans.
• If you choose Original Medicare, note your 6-month Medigap Open Enrollment window.
• Book a free counseling session with your State Health Insurance Assistance Program (SHIP) if you want unbiased help.

After enrollment, and every year

• Cancel employer, COBRA or Marketplace coverage so it ends the day before Medicare begins. Confirm a younger spouse's coverage first.
• Read each plan's Annual Notice of Change every fall.
• Review coverage during the October 15 – December 7 open enrollment.
• If income drops because of a life-changing event such as retirement, ask SSA whether you can request a new IRMAA determination (Form SSA-44).

Part 4: HSA timing

You cannot contribute to an HSA for any month you are enrolled in Medicare, and that includes Part A alone. Because premium-free Part A can be backdated up to 6 months when you sign up after 65, Medicare.gov advises that you and your employer stop HSA contributions 6 months before you apply for Medicare or Social Security. Money already in the HSA can still be used for qualified medical expenses. That generally includes Medicare Part B, Part D and Medicare Advantage premiums, but not Medigap premiums.

2026 Medicare costs

2026 Part B income-related premiums (IRMAA)

For 2026, IRMAA is generally based on the MAGI shown on your 2024 tax return.

Late-enrollment penalties

• Part B: 10% of the standard premium for each full 12-month period you could have had Part B but did not, unless you qualified for a Special Enrollment Period. It usually lasts as long as you have Part B. Hypothetical Waiting 24 months without a Special Enrollment Period means a 20% penalty. On the 2026 premium, that is $202.90 + $40.58 = about $243.50 per month.
• Part D: 1% of the national base beneficiary premium for each full month without Part D or other creditable drug coverage after your IEP, if the gap is 63 days or more. Hypothetical A 14-month gap means 14% × $38.99 ≈ $5.50 per month in 2026, added for as long as you have Part D.
• Part A (only if you must buy it): up to a 10% higher premium for twice the number of years you delayed.

Questions to ask

• Employer or HR: Is our plan primary or secondary to Medicare at my age and employer size? Do I need Part B when I turn 65?
• Retiree plan: Will I lose retiree coverage, for myself or my family, if I join a Medicare plan the employer does not offer?
• Drug plan: Is my current drug coverage creditable?
• Any plan you are considering: Are my doctors in network? Are my drugs on the formulary, and at what tier? What is the yearly out-of-pocket maximum? Do I need referrals or prior authorization?
• SSA: What will my Part B premium be, and can I request a new IRMAA determination after retiring?

Common mistakes

• Assuming COBRA or retiree coverage lets you delay Part B without a penalty.
• Continuing HSA contributions in the 6 months before applying for Medicare after 65.
• Choosing a plan by premium alone without checking doctors and drugs.
• Missing the one-time Medigap Open Enrollment Period, which can limit your later options.
• Forgetting that a large Roth conversion or asset sale can raise Medicare premiums two years later through IRMAA.
• Leaving a younger spouse without coverage when the employer plan ends.

Where to get official help

• Medicare: Medicare.gov, 1-800-MEDICARE (1-800-633-4227); TTY 1-877-486-2048.
• Social Security (enrollment and IRMAA): ssa.gov, 1-800-772-1213.
• Free, unbiased counseling: your State Health Insurance Assistance Program (SHIP). In Illinois, that is the Senior Health Insurance Program through the Illinois Department on Aging.

Related: Medicare at 65 · Medicare and HSA timing · Schedule a conversation

Sources

• Medicare.gov — When Medicare coverage starts (IEP, GEP, SEPs)
• Medicare.gov — Working past 65 (employer coverage, COBRA, HSAs)
• Medicare.gov — Avoid late enrollment penalties
• Medicare.gov — When can I buy a Medigap policy?
• CMS — 2026 Medicare Parts A and B premiums and deductibles; Part D IRMAA
• CMS — Final CY 2026 Part D redesign program instructions ($2,100 threshold)
• Social Security — Medicare enrollment
• Illinois Department on Aging — Senior Health Insurance Program (SHIP)

Educational purposes only. This guide is not individualized financial, investment, tax, legal, Social Security, Medicare or insurance advice. Rules and individual circumstances vary. Verify current official guidance and consult appropriately qualified professionals.