Medicare is the federal health insurance program for people 65 and older. Almost every American ends up on it, including retired teachers and police officers who never paid into Social Security, since many of them paid the separate Medicare tax. The rules for signing up are strict, and a missed deadline can raise your premium for the rest of your life. This guide covers what you need to know before you turn 65.
The four parts
| Part | What it covers | Cost in 2026 |
|---|---|---|
| A | Hospital stays, skilled nursing after a hospital stay, hospice | Free for most people with 40 work credits |
| B | Doctor visits, outpatient care, tests, equipment | $202.90 a month standard premium, $283 yearly deductible |
| C (Medicare Advantage) | A private plan that replaces A and B, often with drug coverage | Varies by plan, often $0 extra beyond Part B |
| D | Prescription drugs | Varies by plan; out-of-pocket drug costs capped at $2,100 for the year |
Part A is free if you or your spouse paid Medicare taxes for at least 10 years (40 credits). Most public employees hired after March 1986 paid Medicare tax even in jobs without Social Security, so they usually qualify. Our credits checker can help you count.
People with higher incomes pay more for Parts B and D. In 2026, the surcharge starts at modified adjusted gross income above about $109,000 for a single person or $218,000 for a married couple, based on your tax return from two years earlier.
When to sign up
Your Initial Enrollment Period is seven months long: the three months before the month you turn 65, your birthday month, and the three months after. If you sign up during the first three months, coverage starts the month you turn 65.
If you already get Social Security when you turn 65, you are signed up for Parts A and B automatically, and your card arrives in the mail. Everyone else has to apply, online at ssa.gov or by phone.
If you miss your initial window, the General Enrollment Period runs from January 1 to March 31 each year, with coverage starting the month after you sign up. Late-enrollment penalties may apply.
Still working at 65?
If you or your spouse have health insurance through a current job at an employer with 20 or more workers, you can usually delay Part B without a penalty. When that job or coverage ends, you get an eight-month Special Enrollment Period to sign up.
Two kinds of coverage do not count as current employment, and catch many people out:
- COBRA, the coverage you keep paying for after leaving a job
- Retiree health insurance from a former employer
If you rely on either one past 65 without Part B, you can end up with a penalty and gaps in coverage. Many retiree health plans for teachers and state workers require you to enroll in Part B at 65 and then pay only after Medicare. Our guide to retiree health insurance explains how public plans handle this.
The penalties
Part B: your premium goes up 10% for every full 12 months you could have had Part B but did not. Wait three years and you pay 30% more, every month, for life.
Part D: if you go 63 days or more without drug coverage at least as good as Medicare’s, you pay an extra 1% of the national base premium for each month you went without, also for life.
Here is how the Part B penalty adds up. Carol turned 65 in 2023 but waited until 2026 to sign up, with no job-based coverage in between. That is three full years late, so her premium is 30% higher: about $264 a month instead of $202.90, an extra $730 a year that never goes away.
Original Medicare or Medicare Advantage
This is the second big choice.
Original Medicare (Parts A and B) lets you see any doctor in the country who takes Medicare. It pays about 80% of most costs, with no yearly cap on what you pay. Most people add a Part D drug plan and a Medigap supplement plan that covers most of the remaining 20%.
Medicare Advantage (Part C) is a private plan that bundles A, B and usually D. Premiums are often low and many plans add dental and vision. In exchange, you usually need to stay in a network and get approval for some care. Every plan has a yearly cap on out-of-pocket costs.
Timing matters for Medigap. You have a six-month Medigap open enrollment window that starts the month you are both 65 and enrolled in Part B. During that window, insurers must sell you any plan at the standard price regardless of your health. After it, in most states, they can turn you down or charge more because of health conditions.
Every year after that
Medicare’s Open Enrollment runs from October 15 to December 7. You can switch between Original Medicare and Medicare Advantage, change Advantage plans, or change Part D plans. New coverage starts January 1. Plans change their drug lists and costs each year, so it is worth checking. Our news post on this year’s open enrollment has the details.
Common questions
Can I get Medicare before 65? Only if you have received Social Security disability benefits for 24 months, or have ALS or end-stage kidney disease.
Does Medicare cover long-term care? No. It covers short skilled-nursing stays after a hospital visit, but not ongoing help with daily living in a nursing home or at home.
Is my spouse covered? No. Medicare is individual. Your spouse enrolls on their own when they turn 65, even if they qualify for free Part A on your work record.
How are premiums paid? If you get Social Security, Part B is taken out of your check. Otherwise Medicare bills you every month or quarter.