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 out form CMS-1763 later to end it. Either way you have no coverage 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 coverage starts, with nothing;
• a higher monthly bill, for the rest of your life.

Before you do anything else, find out which of those three apply to you. If you qualify for a Special Enrollment Period you avoid the wait and the penalty, and usually the gap as well.

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 If you are reading the old rule somewhere, it is out of date.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 Special Enrollment Period — check this first. It removes the wait and the penalty, and usually the gap too. The rule for it 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. There it means drug coverage expected to pay at least as much as Medicare’s, and COBRA and retiree drug coverage often do count. (It has a third meaning again in Medigap, where earlier coverage can shorten a waiting period for a condition you already have. 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. 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 test people miss, and it has two parts, both about your past:

   • When you first became eligible for Part B, you were either covered by an employment-based plan, or you enrolled in Part B then.
   • In every month from then until your employer coverage ended, you kept either Part B or employment-based coverage. As long as you file inside the eight months, the months since it ended are the Special Enrollment Period itself — not a gap the rules hold against you.

   You have to pass both. Two common kinds of reader fail, however recent the job was: someone who declined Part B at 65 with no employer coverage at the time, and someone who dropped Part B, went a while with no coverage of any kind, and only later took a job that had it. Call Social Security at 1-800-772-1213 and ask about the Special Enrollment Period for Part B — they apply both parts.

   If you do qualify there is no penalty. Whether there is a gap depends on when you file, and filing early can remove it entirely.

   File while you still have the employer coverage, or in the first full month after it ends, and Part B starts on the first day of the month you file. No gap at all. If your employer coverage stops in the middle of a month, file during that same month: Part B then starts on the first of it, before the employer coverage even ended, so nothing is left uncovered. Wait until the following month and the rest of the stopping month is a gap you pay for.

   You can instead choose a later start, the first day of any of the next three months. That is worth doing when your employer coverage runs to the end of a month, so Part B begins the day after it stops and you are not paying for both. It does not help if your coverage stops mid-month — every later option starts on the 1st, which puts the gap back.

   File in any later month of the eight, and coverage starts the first day of the month after you file.

2. If an employer, its health plan, or an insurance agent or broker told you that you did not need Part B, say so — and check the date. There is a Special Enrollment Period for exactly that, requested on form CMS-10797. The regulation covers your employer, the group health plan, and agents or brokers of health plans alike. It removes both the wait and the penalty, which is worth real money. Two conditions are easy to miss, and you need both:

   • The misinformation must have reached you on or after January 1, 2023.
   • You must have missed an enrollment period because you relied on that incorrect information.

   Both have to be true. Even then, coverage starts the month after you enroll, not in the past. And the window is short: SSA says this Special Enrollment Period ends on the last day of the sixth month after the month you tell Social Security about the wrong information. You must enroll within it to receive the penalty protection.

3. If a government employee told you wrong, ask for equitable relief. This is a separate remedy for errors by Social Security, Medicare, or someone acting for them. If your wrong information came from an employer, a plan, an agent or a broker, start with step 2 — but ask about this as well, for two reasons. It also covers the case where your employer or insurer was passing on something the government had told them. And unlike step 2 it has no cut-off date at all, so ask about it even for government misinformation before 2023. Ask Social Security for equitable relief by name. Ask even if the wrong information came only from your employer — but do not plan around getting it, and do not wait, because Social Security also asks whether you acted as promptly as could reasonably be expected.

4. If none of that applies, mark January 1 now. Coverage starts the month after you sign up. Sign up in January and coverage starts in February; sign up in March and it starts in April. Each month you wait costs you a month. After March 31 you cannot sign up again 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 counseling 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 route that is already closed.

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 407.25 paragraph (c) sends Part B entitlement during a special enrollment period to 42 CFR 406.24, whose paragraph (e)(1) is the reason filing early removes the gap: if you enroll “in a month during any part of which he or she is covered under a GHP or LGHP on the basis of current employment status, or in the first full month when no longer so covered, coverage begins on the first day of the month of enrollment or, at the individual’s option, on the first day of any of the three following months.” Paragraph (e)(2) gives the later months of the period the ordinary “first day of the month following the month of enrollment”. (407.25(c) — and 407.20(e) — point to 406.24(d), which is the additional-SEP rule; the effective-date rule is (e). There was no re-lettering: the 1996 rule at 61 FR 40346 created all three provisions on the same day with this mismatch already in them. The statute states the rule directly and does not depend on the cross-reference: 42 U.S.C. 1395q(e), and Social Security administers it that way at POMS HI 00805.276. Note that medicare.gov’s consumer page simplifies this to “generally, the first month after you sign up” — the statute, the regulation and the POMS instruction all say otherwise for someone filing while still covered.)

• 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 (form CMS-10797), and it reaches wider than employers alone — it covers information from “the individual’s employer or GHP, agents or brokers of health plans, or any person authorized to act on behalf of such entity”. Paragraph (c)(2) gives it a six-month life: it “begins the day the individual notifies SSA of the employer or GHP misrepresentation, or the incorrect information provided and ends 6 months later”. paragraph (a), subject to its Medicaid exception, generally limits these SEPs 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) (first enrollment) and 408.24(d)(2)(ii) (re-enrollment, which is the reader who dropped Part B later).

• 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.”

• SSA POMS HI 00805.384 — operational eligibility, evidence, enrollment-window end date and coverage start for the employer-misinformation SEP.

Frequently Asked Questions