Medicare enrollees who sign up for Part B after they were first eligible can owe a monthly late enrollment penalty, and Medicare.gov says it “goes up the longer you wait to sign up.” The same page says “you’ll pay the penalty for as long as you have Part B.” In 2026 the standard Part B premium is $202.90 a month, and the penalty is added on top of it.
The question for anyone nearing 65, or already past it, is whether the penalty clock has started. Medicare’s guidance on avoiding penalties puts the charge at an extra 10% for each year a person could have signed up for Part B and didn’t.
Stay ahead of government payment news: Miss an enrollment or claim deadline and the money can be gone. Join the Retirement Money Brief and we’ll send you our 2026 Government Check Reality Tracker as a welcome gift.
Get the Brief + the check tracker →
We may earn a commission from links on this page.
How much does a late sign-up add to the bill?
The charge is 10% for each full 12-month period a person could have signed up for Part B but did not, according to Medicare. It is added to the standard premium, not paid once.
Medicare’s own example uses a 20% penalty for 24 months without coverage. In 2026 that works out to $202.90 plus $40.58, or $243.48, which Medicare rounds to $243.50 a month. The same costs page lists a $283 Part B deductible before Original Medicare starts to pay, and says the premium itself can be higher depending on income. After the deductible, Part B coinsurance is generally 20% of the cost, so the monthly premium and the penalty sit on top of what a person pays at the doctor’s office.
Why does the penalty never go away?
Medicare says late enrollment penalties are “usually charged for as long as you have that type of coverage.” For Part B, that means the extra amount stays in the monthly premium for the life of the coverage. The Social Security Administration, which takes Part B enrollment applications, describes it on its Part B enrollment page as a “lifetime” penalty that grows the longer a person waits.
Because the amount is figured as a percentage of the standard premium, as Medicare’s example shows, it is tied to that year’s premium. Medicare says the premium “can change each year.”
Who can sign up after the first window without paying more?
Medicare says a person generally won’t owe a Part B penalty after qualifying for a Special Enrollment Period or enrolling in a Medicare Savings Program. Its advice is to sign up during the Initial Enrollment Period unless the person has other coverage “similar in value to Medicare (like from an employer).”
Social Security says the same for workers: someone who is still working may qualify for a Special Enrollment Period and can sign up without a penalty. People who miss the first window and do not qualify for a special one can enroll only during the general enrollment period, January 1 through March 31 each year, with coverage starting the month after they enroll, according to the agency. A person in that position can sign up, but the 10% charges for the years already missed apply.
Do Part A and Part D have the same trap?
They have versions of it. Medicare says a person who doesn’t buy Part A when first eligible, usually at 65, might pay a penalty. Most people pay $0 for Part A, but people who must buy it pay either $311 or $565 a month in 2026, so a penalty there lands on a premium that already costs real money. The costs page says there are two ways to avoid a Part D late enrollment penalty, and one is to not go 63 days or more without creditable drug coverage.
Medicare.gov’s costs page, linked above, is the free place to check each part’s figures.
Will your Part B bill be higher than the standard $202.90?
A late penalty is set by Medicare and stays on the bill for life, so the other parts of the Part B amount matter more once it is there. Medicare says the premium can also run higher depending on income, so the penalty is only one piece of what a person pays for Part B.
The story’s penalty is not something a guide can erase, so the turn here is to the rest of the bill. “Cut Your Medicare Bill” puts 2026 Medicare costs at a glance on one table and walks through the surcharge appeal with Form SSA-44 after retirement, divorce or a spouse’s death. It is 11 pages built around ten moves to pay less for the same care.
Get the Medicare costs table and SSA-44 appeal steps in the Cut Your Medicare Bill guide →
This article was produced with AI assistance and edited for accuracy against the sources linked above.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
