Most people know Medicare starts at 65, but the full picture is more nuanced. You may qualify earlier due to disability, ALS, or kidney failure. You might be able to delay without penalty if you are still working. Your spouse's work history can make you eligible even if you never worked. This guide answers every "when can I get Medicare" question with specific 2026 rules and numbers so you can make an informed decision.
The standard Medicare eligibility age is 65 years old. This applies to U.S. citizens and qualifying lawful permanent residents who meet the work history requirements. You become eligible for Medicare on the first day of the month you turn 65 (or the first day of the prior month if your birthday falls on the first of the month—a quirky Social Security rule).
If you are already receiving Social Security retirement benefits or Railroad Retirement Board benefits when you turn 65, you are automatically enrolled in Medicare Part A and Part B. Medicare will mail your red, white, and blue Medicare card approximately three months before your 65th birthday. You do not need to take any action—unless you want to decline Part B (for example, if you have qualifying employer coverage and want to save the $185/month Part B premium).
If you are not yet receiving Social Security at 65 (because you are still working or chose to delay Social Security past 65), you are not automatically enrolled. You must actively sign up through the Social Security Administration at ssa.gov or by visiting your local SSA office during your Initial Enrollment Period.
Medicare Part A is premium-free for most people because they or their spouse paid Medicare payroll taxes for at least 40 quarters (10 years) of work. A quarter of coverage is earned for each $1,730 of earnings in 2026 (up to 4 quarters per year). Most working Americans easily meet this threshold over a career.
If you or your spouse did not accumulate 40 quarters, you can still get Part A by paying a premium:
Part B always requires a premium—$185/month in 2026 for most people, regardless of work history. Part B is optional (you can decline it if you have qualifying employer coverage), but if you decline and do not have a valid reason, you will owe a permanent late enrollment penalty when you do eventually sign up.
If you receive Social Security Disability Insurance benefits, you become eligible for Medicare after a 24-month waiting period. In month 25 of receiving SSDI benefits, you are automatically enrolled in Medicare Part A and Part B. You do not need to apply separately—Medicare enrollment is automatic at that milestone.
This 24-month waiting period begins from the date you were entitled to SSDI benefits (which can be different from when your first check arrived, due to the 5-month SSDI waiting period itself). During the 24-month pre-Medicare window, many people on SSDI have no health coverage or must purchase marketplace insurance—one of the most significant coverage gaps in the U.S. healthcare system.
Once you receive Medicare through SSDI, you can enroll in a Medicare Advantage plan, Medicare Supplement (Medigap), and Part D—though some states have reduced Medigap protections for under-65 beneficiaries compared to those who enrolled at 65.
If you are diagnosed with ALS (Lou Gehrig's disease), you qualify for Medicare immediately—the month your SSDI benefits begin, with no 24-month waiting period. Congress created this exception because ALS is a rapidly progressing terminal disease where waiting two years for Medicare would be unconscionable. If you receive SSDI for ALS, Medicare enrollment is automatic and immediate.
End-Stage Renal Disease—permanent kidney failure requiring dialysis or a transplant—qualifies you for Medicare at any age, but timing depends on the type of treatment:
ESRD Medicare is available regardless of age or work history—a 35-year-old with kidney failure qualifies just as a 65-year-old would.
If you have not personally worked enough quarters to qualify for free Part A at 65, you may be able to qualify through your current or former spouse's work history. The rules:
Widows and widowers can also qualify through a deceased spouse's work record as long as the marriage lasted at least 9 months and you have not remarried before age 60. If you divorced after at least 10 years of marriage, you can use your ex-spouse's work record even if they have remarried—your ex's Medicare eligibility is not affected by your claiming benefits on their record.
U.S. citizenship is not required for Medicare eligibility, but the requirements for lawful permanent residents (green card holders) are strict. To qualify at 65, you must:
If you recently received your green card and have not yet been a lawful permanent resident for 5 years, you cannot enroll in Medicare yet, even if you are over 65. The 5-year clock starts from the date your permanent residency was granted.
Many Americans continue working past 65 with employer-sponsored health insurance. Whether you should sign up for Medicare at 65 or delay depends almost entirely on the size of your employer.
For employers with 20 or more employees, your group health plan is the primary payer at any age. Medicare would pay second, as a secondary insurer. Since you are already well-covered by your employer plan, there is often little practical benefit to paying Part B's $185/month premium while you have good employer coverage. You can defer Part B enrollment until you retire.
When you do retire or lose your employer coverage, you have an 8-month Special Enrollment Period to sign up for Part B with no late penalty. Make sure you enroll within this window—do not wait for the next General Enrollment Period.
You should still enroll in Part A at 65 if it is premium-free (which it is for most people). Part A costs you nothing and can coordinate with your employer plan to cover inpatient hospital costs. The main exception: if you are contributing to an HSA, do not sign up for Part A yet (see the HSA section below).
For small employers with fewer than 20 employees, Medicare is the primary payer once you turn 65, and your group plan pays second. This means if you do not have Medicare and you incur a medical claim, your small employer plan will deny payment for the portion Medicare should have covered as primary—even though you did not have Medicare. You can end up with large out-of-pocket bills that neither plan will pay.
If you work for a small employer, enroll in both Part A and Part B during your Initial Enrollment Period, even if you are happy with your current coverage. Medicare and your employer plan will coordinate to cover most of your costs together.
A Health Savings Account (HSA) is a tax-advantaged account you can use with a high-deductible health plan to save for medical expenses. HSAs offer triple tax benefits: contributions are tax-deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free.
However, the IRS prohibits you from contributing to an HSA once you are enrolled in any part of Medicare—even premium-free Part A. This creates a timing trap for people who plan to delay Medicare while still contributing to an HSA.
The 6-month retroactive rule: When you enroll in Medicare Part A, your coverage can be retroactive for up to 6 months (but not before your 65th birthday). If you sign up for Part A and Medicare retroactively covers you back 6 months, any HSA contributions you made during those 6 months become excess contributions—subject to a 6% IRS excise tax.
What to do: If you want to delay Medicare and keep contributing to your HSA, you must also delay claiming Social Security retirement benefits (because claiming Social Security automatically enrolls you in Part A). Stop all HSA contributions at least 6 months before the date you plan to start Medicare. If you plan to start Medicare at 65, stop HSA contributions when you turn 64 and 6 months.
COBRA (Consolidated Omnibus Budget Reconciliation Act) lets you continue your employer's group health coverage after leaving a job, usually for up to 18 months. Many people assume that being on COBRA when they turn 65 protects them from Medicare late enrollment penalties—it does not.
COBRA is continuation coverage, not active employer-sponsored insurance. It does not give you a Special Enrollment Period for Medicare. If you are on COBRA when you turn 65:
The best strategy when you have COBRA and turn 65: enroll in Medicare and then decide whether to keep COBRA as a secondary supplement (it can help pay deductibles and copays for a short period) or drop COBRA to stop paying premiums. Most people drop COBRA once they have Medicare.
The Social Security Administration manages Medicare enrollment. You can check your eligibility and sign up at ssa.gov or by calling 1-800-772-1213. You can also visit medicare.gov to use their eligibility checker tool. If you have specific questions about your situation—especially around disability, ESRD, or working past 65—calling SSA directly will get you the most accurate personalized answer.