Medicare Doesn’t
Have To Be Complicated

Medicare is the federal health insurance program for people 65 and older. Some people under 65 qualify too, like those who’ve received Social Security disability benefits for 24 months, or who have end-stage kidney disease or ALS. In most cases you also need to be a U.S. citizen, or a permanent resident who’s lived here at least five years in a row.

Part A, the hospital coverage, is premium-free for most people who’ve worked and paid Medicare taxes for at least 10 years. If you haven’t, you may still be able to buy it. I’d always check your own situation on Medicare.gov before counting on it.

Your Initial Enrollment Period lasts seven months. It starts three months before the month you turn 65, includes your birthday month, and runs three months after. If you sign up before your birthday month, coverage can start the month you turn 65.

Miss that window and you can sign up between January 1 and March 31 each year, but coverage starts later and you may pay a lifetime late penalty on Part B. If you’re still working and have coverage through your job, or your spouse’s, you may be able to wait without a penalty. Every fall, October 15 to December 7, is when you can switch plans. Our Medicare enrollment timeline walks through it step by step.

Original Medicare, Parts A and B, is run by the federal government. You can see any doctor or hospital in the country that accepts Medicare, with no network to worry about. But there’s no yearly cap on what you pay out of pocket, so many people add a Medigap plan and a separate Part D drug plan.

Medicare Advantage, also called Part C, comes from private insurance companies. It usually bundles in drug coverage, sometimes adds extras like dental or vision, and has a yearly out-of-pocket limit. The trade-off is that you usually have to use the plan’s network, and some care needs approval first. Our coverage comparison guide lays them side by side.

You don’t have to have one, but Original Medicare leaves gaps. There are deductibles, copays, and coinsurance, and none of it is capped. A Medigap plan is sold by private insurers and helps pay some or all of those costs. The plans are standardized with letters, like Plan G or Plan N, so the same letter covers the same benefits no matter who sells it, though the prices can be very different.

The best time to buy is your six-month Medigap open enrollment period, which starts when you’re 65 or older and enrolled in Part B. After that, insurers in most states can ask health questions or charge you more. You can’t use Medigap with a Medicare Advantage plan. Our Medicare supplements page goes into more detail.

Part D covers prescription drugs. It’s sold by private insurance companies, either as a standalone plan you add to Original Medicare or built into a Medicare Advantage plan. Every plan has a list of covered drugs, called a formulary, and what you pay depends on which tier your drug is on. Check that your medications are on the list before you pick a plan.

Since 2025 there’s also a yearly cap on what you pay out of pocket for covered drugs, around $2,000 and adjusted each year. If you skip Part D when you’re first eligible and don’t have other drug coverage that’s as good as Medicare’s, you can face a late penalty that gets added to your premium for as long as you have the coverage.

It depends on the parts you choose. Part A is premium-free for most people. Part B has a monthly premium and a yearly deductible, and both change every year, so we keep the current numbers on our Medicare Part B cost in 2026 page. Higher earners pay more through an income-based surcharge called IRMAA, and our IRMAA calculator can help you see if it will apply to you.

Part D and Medigap premiums vary by plan. Medicare Advantage plans may have a low or even $0 premium, but they charge copays when you get care. And then there’s what Medicare doesn’t pay for, like most long-term care, which is why it helps to plan for that ahead of time.