You generally apply for Medicare around the time you turn 65, during a 7‑month window called your Initial Enrollment Period.

Quick scoop: when do I apply for Medicare?

For most people, you can sign up:

  • 3 months before the month you turn 65
  • The month you turn 65
  • 3 months after the month you turn 65

That’s a total of 7 months.

If you enroll in that window, you usually avoid late penalties and gaps in coverage.

The main situations (in plain English)

1. You’re turning 65 and not working (or only part‑time)

  • This is the “standard” case.
  • Your 7‑month Initial Enrollment Period (IEP) starts 3 months before your 65th birthday month and ends 3 months after.
  • Most people sign up for Part A (hospital) and Part B (medical) during this time.

Example:
If your birthday is in July, you can sign up from April 1 through October 31.

2. You’re already getting Social Security

  • If you’re already receiving Social Security when you turn 65, you’re usually automatically enrolled in Medicare Part A and Part B.
  • Your Medicare card typically arrives about 3 months before you turn 65.
  • You can choose to decline Part B if you don’t want to pay the monthly premium yet.

3. You (or your spouse) are still working at 65 with large‑employer

coverage

  • If you or your spouse are still actively working for an employer with about 20+ employees and have that employer’s coverage, you may be able to delay Part B without penalty.
  • When that job or coverage ends, you get a Special Enrollment Period (SEP) to sign up for Medicare.

Typical SEP rules:

  • Starts when you stop working or lose employer coverage.
  • You usually have up to 8 months to enroll in Part A and Part B without a late penalty.

4. You missed your Initial or Special Enrollment Period

If you don’t sign up when first eligible and don’t qualify for a Special Enrollment Period:

  • You can use the General Enrollment Period (GEP) :
    • January 1 to March 31 each year.
  • Coverage start dates depend on when you enroll in that window; enrolling late can mean a coverage gap and permanent late penalties on Part B (and sometimes Part D).

5. You qualify before 65 (disability or certain conditions)

  • Some people qualify for Medicare earlier due to disability, ALS, or End‑Stage Renal Disease (ESRD).
  • In those cases, enrollment timing is tied to disability benefit timelines, not age 65.

Mini table: key Medicare sign‑up windows

Situation When to apply Risk if you wait
Turning 65, not working / no large employer plan 7‑month Initial Enrollment Period (3 months before to 3 months after 65) Late penalties, coverage gap
Still working at 65 with large‑employer coverage During Special Enrollment Period after job/coverage ends (up to 8 months) Penalties and gap if SEP is missed
Missed IEP and SEP General Enrollment Period (Jan 1–Mar 31) Coverage delay, higher lifetime premiums
[9][1][5][7][10][3]

Forum‑style tip (since this topic trends a lot)

“Medicare is so confusing—go talk to a local Medicare‑focused agent or counselor. It’s usually free, and they walk you through your options.”

Many retirees also recommend:

  • Checking the official Medicare.gov “When can I sign up?” tool to confirm your exact dates.
  • Contacting Social Security or a trusted Medicare counselor a few months before you turn 65 so you don’t miss your window.

TL;DR

  • Most people should apply sometime in the 7 months around their 65th birthday.
  • If you’re still working with good employer coverage, you may be able to delay and use a Special Enrollment Period later.
  • Miss both and you’re stuck with the General Enrollment Period and possible penalties.

Information gathered from public forums or data available on the internet and portrayed here.