Medicare Eligibility

You are eligible for Medicare the first of the month you turn 65, with two exceptions:

  1. If your birthday is the first of the month, you’re eligible the first of the prior month.
  2. If you’re under 65 and have been on Social Security Disability for 24 months, you’re eligible the 25th month.

The following situations apply to those who are not one of the above exceptions.

Enrolling in Medicare at age 65+*

  • Turning 65, already on Social Security.
    Parts A & B are issued to you automatically, but you have an option to decline B. Normally the only reason to decline B is that you will be covered by employer plan, not a retiree plan. You will receive your Medicare card in the mail about 3 months before Medicare begins.
  • Qualifying under spouse’s Social Security for Medicare.
    Requires a visit to the Social Security office with both parties. Need to prove age, citizenship, address & marriage. Bring birth certificate, drivers license and marriage license.
  • Turning 65, on individual coverage or leaving group medical plan – not taking Social Security.
    Initial enrollment window starts 3 months before the month you turn 65. Visit, about halfway down the page, in the “Resources” section, is a link “Apply for Medicare” – click it. On the next page, click “Apply for Medicare Only” to begin. The whole process takes 10-30 minutes.
  • Turning 65, staying on group medical plan.
    You will not be able to contribute to a HSA if you enroll in Medicare Part A or B. If you are on your employer’s group plan and the company has under 20 employees both A and B will be required. You may want to investigate going to a Supplement and Drug Plan for cost and/or benefits. Part A can be applied for online anytime starting 3 months prior to your eligibility date for Medicare. You can apply later for Part A, and in that case it will be retroactive to up to 6 months (but no earlier than your Medicare eligibility date.)
  • 65+, on Part A for over 3 months, leaving group medical plan and needing Part B.
    You have 8 months to sign up for Part B without a penalty. COBRA is not a qualified plan and many retiree plans are not qualified. To sign up for Part B while you’re employed or during the 8 months after employment ends, complete form CMS-40B and for employer CMS-L564. (Both these forms are linked at the bottom of this page.)
  • 65 and 3 months+, leaving group coverage and needing Parts A and B.
  • Visit, about halfway down the page, in the “Resources” section, is a link “Apply for Medicare” – click it. On the next page, click “Apply for Medicare Only” to begin. The whole process takes 10-30 minutes. They will required you to Mail or Fax and employer coverage verification Form CMS-L564.
  • 65+, on Part A for less than 4 months, and want Part B
    Use form CMS-40B below. Only effective the 1st of the month.
    Beginning 1/1/2023, Part B can be effective as early as the first of the month after you apply.
  • 65+ less than 4 months, and need parts A and B
    Enrolling in A & B
    can be done online. Part A will be retroactively effective to the first of the month you were eligible. In light of the retroactive Part A enrollment, refer to “**Delayed starts for late enrollment” above to determine Part B effective dates.
  • 65+ leaving group, need Medicare Parts A & B.
    1. See “Turning 65, on individual coverage…” above to start enrollment.
    2. To avoid delays and penalties, see “65+, on Part A for over 3 months…” above.
  • 65+ going back on group, needing to terminate Part B
    To terminate Part B when returning to a qualified 20+ group plan, use form CMS-1763 (below).
  • On Group having Part A & B over 3 months, eligible for Group and changing to Medicare.
    Medical underwriting is normally required for popular Plan G.
  • Missed the initial enrollment and are not covered by a qualified medical plan. Must wait until the first quarter of the year to apply with coverage starting July 1st.  A lifetime premium  rate-up charged.
  • On Social Security Disability for 24 months, Medicare A and B enrollment is automatic, effective the 25th month.
  • Birthday is the 1st of the month? You’re eligible for Medicare the 1st of the prior month.
  • On HSA Qualified Medical? To continue making contributions, do not enroll in A or B.
  • COBRA over 65? I cannot see a reason for it. It requires you to carry both Medicare A & B, and is not considered qualified coverage. Additionally, you lose Medicare Supplement open enrollment after 6 months.

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Medicare Part D (Rx) – you will need your Medicare card to apply.  Most plans purchased cost $17-30/mo*. I do not sell these plans but will show you how to select and buy the best option. This is a link to my website’s page on Part D.

*Remember the authority on the subject is