Opted Out of Medicare Part B: What It Costs to Get Back In

What This Means

Medicare Part B is the half that pays for doctors, tests, outpatient treatment and most equipment. (Part A is the hospital half.) You either turned Part B down when Medicare first offered it, or you filled in form CMS-1763 later to end it. Either way you have no cover for any of that now, and those bills are yours to pay.

Coming back is not simply a matter of changing your mind. For most people it means three separate things:

• a wait — you cannot sign up whenever you like;
• a gap — months between now and the day cover starts, with nothing;
• a higher monthly bill, for the rest of your life.

It is worth knowing the exact shape of that before you do anything else, because one of the three can sometimes be avoided altogether.

Why This Happens

Part B has a monthly premium, and the people who drop it are usually reacting to that. The common reasons are all reasonable ones:

• You had other coverage and were told you did not need Part B. Sometimes that advice was right. Often it was not.
• You retired abroad and stopped using American doctors.
• The premium was taken out of a Social Security payment that was already smaller than you expected.
• You were automatically enrolled and did not want it. If you were already drawing Social Security when you turned 65, Medicare enrolled you in Part A and Part B without your asking, and the package that arrived explained how to decline Part B.

None of those are mistakes in themselves. The mistake, when there is one, is almost always about what counts as “other coverage” — and that is the next section.

What It Costs to Come Back

The wait. Unless you qualify for a Special Enrollment Period, you can only sign up for Part B between January 1 and March 31. This is called the General Enrollment Period. Coverage then starts the month after you sign up.

That last point changed recently, and it matters. Coverage used to start on July 1 no matter when in those three months you signed up. A law passed in 2021 changed it from 2023, so signing up in January now means coverage in February rather than a five-month wait. Some Medicare booklets still in circulation describe the old July 1 rule — CMS booklet 11036, “Enrolling in Medicare Part A & Part B”, is still on medicare.gov saying it. If you are reading the old rule somewhere, it is out of date.

The gap. Between now and the month your coverage starts, you have no Part B. Every doctor’s visit, test and outpatient procedure is yours to pay in full.

The penalty. For each full 12-month period you could have had Part B and did not, your premium goes up by 10%. The increase is calculated on the standard premium — $202.90 in 2026 — not on whatever you personally end up paying. So one full year missed is about $20 a month, two full years about $40 a month, three about $61.

You pay it every month, for as long as you have Part B. It does not expire, and there is no forgiveness for having paid it long enough. A 68-year-old who missed two years and lives to 88 pays roughly $9,700 in penalty alone at today’s premium.

The one that is worth checking first. You avoid all three if you qualify for a Special Enrollment Period — and the rule for that is narrower than most people are told.

For Part B, what protects you is coverage from current employment: a group health plan through a job you or your spouse are actively working at. That is the whole list. It does not matter how comprehensive your coverage is or how much it costs you. COBRA, retiree coverage, VA health care and a Marketplace plan are none of them current employment coverage, and none of them protects you from the Part B penalty.

You may have heard the phrase “creditable coverage” and assumed it applies here. It does not. In Medicare enrollment that phrase belongs to Part D, where it means drug coverage expected to pay at least as much as Medicare’s — and COBRA and retiree drug coverage often do count for that. (It has a third meaning again in Medigap, where earlier coverage can shorten a pre-existing-condition waiting period. Different rule, different page.) For Part B there is no such concept at all. Confusing the three is how most people on this page got here.

When employment coverage does end, the Special Enrollment Period runs for eight months. The regulation counts eight consecutive months in which you are not covered by an employment-based plan — so in plain terms the clock starts when the job ends or the coverage ends, whichever comes first, not whichever comes last. Do not wait for the later date.

What To Do Next

1. Work out whether you have a Special Enrollment Period. The timing test is the obvious half: were you, or your spouse, actively working with health coverage through that job at any point in the last eight months? There is a second half people miss. The regulation also asks that when you were first eligible for Part B you were either covered by an employment-based plan or you enrolled in Part B then, and that in every month since you kept either Part B or employment-based coverage. Someone who declined Part B at 65 with no employer coverage, or who dropped it and spent a stretch with nothing at all, does not qualify however recent the job was. Call Social Security on 1-800-772-1213 and ask about the Special Enrollment Period for Part B — they apply both halves.

   If you do qualify there is no penalty. Whether there is a gap depends on when you file: coverage generally starts the month after you sign up, but if you enrol while still covered, or in the first full month after the coverage ends, you can ask for a start date up to three months out and line it up exactly.

2. If an employer told you that you did not need Part B, say so — and check the date. There is a Special Enrollment Period for people given bad information by an employer or its health plan, requested on form CMS-10797. It removes both the wait and the penalty, which is worth real money. Two conditions people are not told about: the misinformation must have reached you on or after January 1, 2023, and it must have reached you before the close of an enrollment period you could then have used. Coverage starts the month after you enrol, not in the past.

3. If a government employee told you wrong, ask for equitable relief. This is a separate remedy, and it applies only to errors by Social Security, Medicare, or someone acting for them — not to an employer, an insurance agent or a broker. Ask Social Security for it by name.

4. If none of that applies, mark January 1 now. Coverage starts the month after you sign up, so signing up in January means February cover and signing up in March means April — each month you wait costs a month, and after March 31 the door shuts until the following January. You can sign up online at ssa.gov/medicare, by phone, or at a Social Security office.

5. Get free help before you commit to anything. Every state runs a free Medicare counselling service, called a SHIP, with no connection to any insurance company. Find yours at shiphelp.org. They will work through the Special Enrollment Period question with you at no cost.

6. Leave Part A alone. If you are drawing Social Security you cannot give up premium-free Part A on its own; the only route is withdrawing your Social Security application and repaying everything you have received. And that route is closed to most people anyway — Social Security accepts a withdrawal only within 12 months of your first month of entitlement, and only once in a lifetime. Do not spend money on advice about a door that is already shut.

Sources

• 42 CFR 408.22 and 408.24 — the Part B late enrollment penalty: 10% of the base premium for each full 12 months of delayed enrollment, payable for as long as enrollment continues.
• CMS: 2026 Medicare Parts A & B Premiums and Deductibles (published November 14, 2025) — the $202.90 standard Part B premium used for every penalty figure on this page.
• Medicare.gov: When does Medicare coverage start? — the General Enrollment Period runs January 1 to March 31, and “your coverage starts the month after you sign up.”
• CMS: Implementing Certain Provisions of the Consolidated Appropriations Act, 2021 — the law that replaced the old July 1 start date, effective January 1, 2023. See also 42 CFR 407.25.
• 42 CFR 407.20 is the Part B special enrollment period, and its paragraph (b) carries the continuity conditions described above; it defers to 42 CFR 406.24 for the length, whose paragraph (b)(2) ends the period “on the last day of the eighth consecutive month during which the individual is at no time enrolled in a group health plan … by reason of current employment status.” Cite both — part 406 governs hospital insurance. The plain-English “whichever comes first” is Medicare’s rendering of that count, not the regulation’s own words.
• 42 CFR 407.23 — the exceptional-conditions Special Enrollment Periods. Paragraph (c) is the one for misinformation from an employer or its health plan (form CMS-10797); paragraph (a) limits all of them to “exceptional conditions that took place on or after January 1, 2023”, and paragraph (c)(3) makes entitlement begin “the first day of the month following the month of enrollment” — so it waives the penalty but does not backdate. 42 CFR 406.27 is the Part A equivalent. The penalty waiver itself is at 42 CFR 408.24(b)(2).
• 42 CFR 407.32 — equitable relief, available only where the error was made by a federal employee or someone acting on the government’s behalf.
• 42 CFR 407.17 — automatic enrollment in Part B, and how it is declined.
• SSA POMS HI 00801.002 — “Individuals entitled to monthly benefits which confer eligibility for HI may not waive HI entitlement,” and withdrawal “requires repayment of all RSDI and HI benefit payments made.” SSA POMS GN 00206.005 carries the limits that close that route for most people: the request must come “within 12 months of the first month of entitlement”, and a claimant “is limited to one approved RIB withdrawal in their lifetime.”

Frequently Asked Questions