Part B special enrollment period in Oregon

The Part B special enrollment period (SEP) is the federal rule that lets people who delayed Part B because of job-based coverage sign up later without the lifetime late penalty. Used on time it is a clean handoff from job coverage to Medicare; missed, it can mean months without coverage and a permanent premium increase.

What the Part B special enrollment period is

Most people sign up for Part B during their 7-month Initial Enrollment Period around their 65th birthday. If you skipped it because you had coverage from current work, the SEP lets you sign up later without a penalty. Without it, you would have to wait for the General Enrollment Period (January 1 – March 31, with coverage starting the month after you sign up) and pay a penalty for as long as you have Part B.

Who qualifies

• You had group health plan coverage based on current employment, yours or your spouse's, while you were eligible for Medicare. (If you are 65 or older, the employer generally needs 20 or more employees for that plan to pay first; see employer plan coordination.)
• You are signing up while you still have that coverage, or within 8 months after the job or the coverage ends.

These don't count as coverage from current employment:

• COBRA
• Retiree coverage
• Marketplace plans and individual policies
• VA health care and TRICARE (TRICARE For Life requires Part B)
• Medicaid (OHP)

The 8-month window

Your 8 months start the month after the earlier of: the month the job ends, or the month the group coverage ends.

Form CMS-L564: the document that matters

• Download Form CMS-L564 from CMS.
• Section A: you complete it.
• Section B: your employer completes and signs it, with the dates of your group coverage based on current employment. If you were covered through your spouse's job, it is your spouse's employer.
• Send it to Social Security with Form CMS-40B, the Part B application.

Ask for it before your last day. Former employers can be slow to respond, and the 8 months keep running. If an employer can't complete Section B, Social Security accepts other proof of group coverage from current employment, such as pay stubs or tax forms showing health premiums deducted; ask Social Security what to send.

How to sign up during the special enrollment period

1. Get Form CMS-L564 completed. Ideally before your last day of work.
2. Complete Form CMS-40B. The Part B application, available from CMS and Social Security.
3. Send both to Social Security. Online through ssa.gov, by mail or fax to your local office, or in person. Find your nearest Oregon office with Social Security's office locator, or call 1-800-772-1213 (TTY 1-800-325-0778).
4. Ask for the right start date. Part B generally starts the month after you sign up. If you sign up while still covered, or in the first full month after coverage ends, you can ask for a start up to 3 months later to line up with the end of job coverage.
5. Join a drug or Medicare Advantage plan within 2 months. After job coverage ends, you have 2 full months to join a Medicare Advantage plan or a Part D plan.
6. Buy Medigap within 6 months if you want it. If you are 65 or older, your one-time Medigap open enrollment period starts when Part B starts. During it, companies in Oregon must sell you any policy they offer, regardless of health. See Medigap in Oregon.

To compare Medicare Advantage, Medigap and Part D plans from the companies they work with, you can request a call from a licensed insurance agent.

The COBRA trap

COBRA does not extend your Part B window, however long you keep it.

Example: Sarah works for a Portland company. She turns 65 in February 2026 and delays Part B because she is still working. She leaves the job in May 2026 (coverage ends May 31) and elects 18 months of COBRA, planning to sign up for Part B when COBRA ends in late 2027.

What happens: her 8-month window ran June 1, 2026 through January 31, 2027. When COBRA ends, she can sign up only in the General Enrollment Period (January 1 – March 31), with Part B starting the month after she signs up, and she will owe a Part B late penalty for as long as she has Part B. Meanwhile COBRA, which pays after Medicare, may have paid only part of her bills.

The fix: sign up for Part B within the 8 months, even if you are on COBRA.

The retiree-coverage trap

Retiree coverage from a former employer (common with public employers and large organizations in Oregon) is not coverage from current employment and doesn't extend the window. Most retiree plans pay after Medicare and expect you to have Part A and Part B. In Oregon, PEBB and OEBB retiree medical coverage ends when you become eligible for Medicare, and the PERS Retirement Health Insurance Account subsidy requires both Part A and Part B. See PEBB and OEBB.

If you miss the special enrollment period

• You can sign up during the General Enrollment Period, January 1 through March 31 each year.
• Coverage starts the month after you sign up.
• You will usually owe the Part B late penalty for as long as you have Part B.
• Since 2023, Social Security can also grant a Part A or Part B special enrollment period in some exceptional situations, such as a declared emergency or disaster, an employer or health plan giving you wrong information, release from incarceration, or losing Medicaid. Ask Social Security if one applies to you.

The Part B late-enrollment penalty

The penalty is 10% of the standard Part B premium for each full 12-month period you could have had Part B but didn't, and it is added to your premium for as long as you have Part B.

Example: if you went 3 full years without Part B and without a special enrollment period, your penalty is 30% of the standard premium. With the 2026 standard premium of $202.90, that is $60.87 more each month, and the penalty rises whenever the standard premium does.

Where to get help in Oregon

• Social Security handles Part B sign-up: 1-800-772-1213 (TTY 1-800-325-0778), ssa.gov, or a local office.
• Medicare answers coverage questions: 1-800-MEDICARE (1-800-633-4227, TTY 1-877-486-2048).
• Plan choices: you can request a call from a licensed insurance agent for help choosing a Medicare Advantage plan or a Medigap policy and Part D plan.

Related guides

• Working past 65 in Oregon
• Employer plan and Medicare coordination
• Part D creditable coverage
• What happens if I miss Medicare enrollment in Oregon?

Sources

• Medicare.gov — Working past 65 (8-month special enrollment period, COBRA)
• Medicare.gov — When does Medicare coverage start?
• CMS — Form CMS-L564, Request for Employment Information
• Social Security — Sign up for Medicare
• 42 CFR § 407.20, Special enrollment periods related to coverage under group health plans (via Cornell LII)
• 42 CFR § 407.23, Special enrollment periods for exceptional conditions (via Cornell LII)
• Medicare.gov — Special Enrollment Periods (2 months to join a plan after job coverage ends)
• Medicare.gov — When can I buy Medigap?
• CMS — 2026 Medicare Parts A & B Premiums and Deductibles

Frequently asked questions

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