Medicare Eligibility Is More Than Just Turning 65—There’s a Lot More to Know

Key Takeaways

• Medicare eligibility rules involve more than just age. Work history, disability status, and certain medical conditions also determine your access and timing.

• Failing to understand enrollment periods and Part B requirements can lead to penalties and long-term coverage gaps.

Reaching Age 65 Is Just the Beginning

Many people assume that turning 65 automatically enrolls them in Medicare. That isn’t always true. While age is the most common path to eligibility, you must meet specific conditions to receive full benefits—and failing to act at the right time can cost you.

Medicare is not a single program. It’s made up of several parts, each with different rules and timelines. Understanding the full picture is essential if you want to avoid late penalties or gaps in coverage.

Basic Age and Work Requirements

If you’re 65 or older, you generally qualify for Medicare if you:

• Are a U.S. citizen or a permanent legal resident who has lived in the U.S. for at least five continuous years.

• Have worked and paid Medicare taxes for at least 10 years (40 quarters).

Those who meet these conditions are typically eligible for premium-free Medicare Part A, which covers hospital insurance. However, you still need to enroll in Part B (medical insurance) and pay a monthly premium for it unless you have other qualifying coverage.

What If You Haven’t Worked Enough?

If you haven’t paid Medicare taxes for 40 quarters, you may still get Medicare, but you’ll pay a monthly premium for Part A. In 2025, this premium is up to $518 per month depending on how many quarters you worked.

If your spouse has enough work history—even if you don’t—you may qualify for premium-free Part A through their record. This includes current spouses, divorced spouses (if the marriage lasted 10 years or more), and widows/widowers.

Disability and Medicare Before Age 65

You don’t have to be 65 to be eligible for Medicare. If you’re under 65, you qualify automatically after receiving Social Security Disability Insurance (SSDI) for 24 months. The 2-year waiting period starts from the first month you’re eligible for SSDI, not the date of application approval.

However, if you have Amyotrophic Lateral Sclerosis (ALS) or End-Stage Renal Disease (ESRD), you may qualify for Medicare immediately or after a shorter wait:

• ALS: You become eligible for Medicare the same month your SSDI benefits begin.

• ESRD: Eligibility typically starts after three months of dialysis or immediately if you undergo a kidney transplant.

Enrollment Doesn’t Happen Automatically for Everyone

If you’re already receiving Social Security or Railroad Retirement Board (RRB) benefits when you turn 65, you’re automatically enrolled in Medicare Parts A and B. Your red, white, and blue Medicare card arrives a few months before your birthday.

But if you’re not drawing Social Security or RRB benefits, you must actively enroll in Medicare. If you don’t, you could face permanent late penalties.

Initial Enrollment Period (IEP)

You have a 7-month window to enroll in Medicare when you first become eligible based on age:

• Starts 3 months before the month you turn 65

• Includes your birth month

• Ends 3 months after your birth month

Enrolling early ensures your coverage begins as soon as possible. Delaying enrollment until your birth month or later can cause a gap in coverage.

General Enrollment Period (GEP)

If you miss your IEP, you can enroll during the General Enrollment Period from January 1 to March 31 each year. However, coverage doesn’t begin until July 1, and you may face late enrollment penalties, especially for Part B.

In 2025, the late enrollment penalty for Part B is 10% for each 12-month period you delayed, and it’s added to your premium permanently.

Special Enrollment Periods (SEP)

You may qualify for a Special Enrollment Period if you have coverage through an employer (or a spouse’s employer) when you first become eligible. This includes:

• Group health plans from a current employer

• COBRA does not count as creditable coverage for delaying Part B without penalty

When the employer coverage ends, you have 8 months to enroll in Part B without penalty. The SEP starts the month after your employment or group coverage ends—whichever comes first.

Medicare and Health Savings Accounts (HSAs)

You can’t contribute to a Health Savings Account (HSA) once you enroll in any part of Medicare, including Part A. If you delay enrollment to keep contributing, stop HSA contributions six months before you sign up for Medicare to avoid tax penalties. That’s because Medicare coverage is retroactive up to six months (but never before age 65).

Medicaid and Dual Eligibility

If you have limited income and resources, you may qualify for both Medicare and Medicaid. This is called dual eligibility. Medicaid can help cover premiums, deductibles, and out-of-pocket costs for Medicare services.

In 2025, eligibility levels vary by state, but programs include:

• Qualified Medicare Beneficiary (QMB): Pays Part A and Part B premiums, deductibles, and coinsurance

• Specified Low-Income Medicare Beneficiary (SLMB): Helps pay Part B premiums

• Qualified Individual (QI): Also assists with Part B premiums

TRICARE, VA Benefits, and Other Coverage

If you’re a military retiree, TRICARE for Life acts as a secondary payer to Medicare once you enroll in both Part A and Part B. VA coverage doesn’t replace Medicare—you should still enroll in Medicare to access non-VA care.

If you worked in the public sector and didn’t pay into Social Security, you may be subject to the Government Pension Offset (GPO), which affects spousal benefits, but not Medicare eligibility.

Medicare for Non-Citizens and Green Card Holders

Permanent residents (green card holders) can qualify for Medicare at 65 if they:

• Have lived in the U.S. lawfully for at least five continuous years

• Meet the same work or spousal work history requirements as citizens

However, some non-citizens may be required to pay full premiums for Part A and B if they lack a qualifying work record.

Common Mistakes That Lead to Penalties

Many people make costly mistakes simply by misunderstanding when or how to enroll. Here are some common missteps:

• Assuming enrollment is automatic when you’re not receiving Social Security

• Missing your Initial Enrollment Period

• Delaying Part B without having creditable coverage

• Contributing to an HSA too close to your Medicare enrollment date

Avoiding these pitfalls starts with understanding the full scope of what makes you eligible—and when action is required.

Planning Ahead Means Fewer Surprises

Whether you’re approaching 65, living with a disability, or navigating the health system as a recent immigrant, Medicare eligibility isn’t a one-size-fits-all issue. Knowing when and how to act can prevent coverage gaps, reduce costs, and protect you from penalties.

If you’re unsure where you stand or what actions you need to take, reach out to a licensed agent listed on this website. They can help you evaluate your situation and enroll at the right time.