Most people qualify for Medicare by turning 65 and having enough work history to earn premium-free coverage. But age isn’t the only path. You can also qualify through a disability or a specific medical condition, regardless of how old you are. The requirements differ depending on which part of Medicare you’re enrolling in and how long you or your spouse paid into the system through payroll taxes.
The Standard Path: Turning 65
The most common way to qualify for Medicare is reaching age 65. To be eligible, you need to be a U.S. citizen or a permanent resident who has lived in the United States for at least five continuous years. There is no income limit or asset test. Medicare is not a means-tested program, so your financial situation does not affect whether you qualify.
If you’re already receiving Social Security benefits when you turn 65, you’ll be automatically enrolled in Part A (hospital coverage) and Part B (outpatient and doctor coverage). If you haven’t started collecting Social Security yet, you’ll need to sign up yourself through the Social Security Administration.
How Work Credits Determine Your Premium
Your work history doesn’t determine whether you can get Medicare, but it determines whether you’ll pay a monthly premium for Part A. The Social Security Administration tracks your earnings through a system of credits. In 2026, you earn one credit for every $1,890 in wages, up to a maximum of four credits per year. That means earning roughly $7,560 in a year maxes out your credits for that year.
If you or your spouse accumulated 40 or more credits (about 10 years of work), you qualify for premium-free Part A. That’s the goal for most people, and the majority of enrollees hit this threshold without thinking about it.
If you have fewer than 40 credits, you can still enroll in Part A, but you’ll pay a monthly premium. The cost in 2025 is either $311 or $565 per month, depending on whether you have at least 30 credits or fewer than 30. These premiums add up significantly over time, which makes it worth checking your credit count with Social Security before you turn 65.
Part B Premiums and Income Adjustments
Part B works differently. Everyone pays a monthly premium for it, regardless of work history. The standard premium in 2025 is $185.00 per month. However, if your income is above a certain threshold, you’ll pay more.
These surcharges are based on your modified adjusted gross income from two years prior. For 2025, the brackets look like this:
- $106,000 or less (individual) / $212,000 or less (joint): $185.00 per month
- $106,001 to $133,000 (individual) / $212,001 to $266,000 (joint): $259.00 per month
- $133,001 to $167,000 (individual) / $266,001 to $334,000 (joint): $370.00 per month
- $167,001 to $200,000 (individual) / $334,001 to $400,000 (joint): $480.90 per month
- $200,001 to $499,999 (individual) / $400,001 to $749,999 (joint): $591.90 per month
- $500,000 or more (individual) / $750,000 or more (joint): $628.90 per month
If you’re married but file a separate tax return and lived with your spouse at any time during the year, the brackets are less favorable. Income above $106,000 in that scenario jumps straight to $591.90 per month.
Qualifying Through Disability Before 65
You don’t have to wait until 65 if you have a qualifying disability. Anyone receiving Social Security Disability Insurance (SSDI) benefits becomes eligible for Medicare after a 24-month waiting period. The clock starts from your first month of disability benefit entitlement, not from when you applied or were approved.
If you were previously on disability benefits and your condition returns, some of those earlier months may count toward the 24-month requirement. This applies if your new disability begins within 60 months of when your previous benefits ended. For disabled widows, widowers, or adults who qualified through childhood disability benefits, that window extends to 84 months. If your current condition is the same as or directly related to your previous disability, there’s no time limit at all.
Qualifying With Kidney Failure or ALS
Two medical conditions can qualify you for Medicare at any age, with no 24-month wait.
If you have end-stage renal disease (permanent kidney failure requiring dialysis or a transplant), you’re eligible for Medicare regardless of age. You need to meet one additional criterion: either you or your spouse must have worked long enough under Social Security, or you must already be receiving Social Security or Railroad Retirement benefits. Dependent children of qualifying workers are also covered.
Coverage timing depends on your treatment. If you’re starting dialysis, Medicare typically kicks in on the first day of the fourth month of treatments. You can shorten that waiting period to the first month if you train for home dialysis at a Medicare-certified facility. If you’re getting a kidney transplant, coverage can begin the month you’re admitted to the hospital for the procedure, as long as the transplant happens within two months of admission.
Amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease) is the other condition that triggers immediate Medicare eligibility. Coverage begins as soon as your SSDI benefits start, with no waiting period.
Your Enrollment Window
Qualifying for Medicare and actually enrolling are two separate steps, and timing matters. Your Initial Enrollment Period is a seven-month window that starts three months before the month you turn 65 and ends three months after it. Signing up during the first three months generally gets your coverage started on the first day of your birthday month.
If you miss this window, the consequences are lasting. Part B carries a late enrollment penalty of 10% added to your premium for every full 12-month period you were eligible but didn’t sign up. Part D (prescription drug coverage) adds 1% per month of delay. These penalties don’t expire. They stay attached to your premium for as long as you have Medicare.
There is an exception if you delayed enrollment because you had coverage through an employer. In that case, you get a Special Enrollment Period to sign up without penalty once your employer coverage ends. But if you simply forgot or didn’t realize you needed to enroll, the penalty applies.
Non-Citizens and Residency Rules
If you’re not a U.S. citizen, you can still qualify for Medicare, but only if you’ve been lawfully admitted as a permanent resident and have lived continuously in the United States for at least five years before applying. Temporary visa holders, undocumented residents, and permanent residents who haven’t met the five-year residency requirement are not eligible. The same work credit rules apply: if you or your spouse accumulated 40 credits through U.S. employment, Part A is premium-free. If not, you can purchase it at the higher premium rate.