Turning 65 while you are still working raises questions your HR department may not answer fully: whether to take Part A, whether to delay Part B, what happens to your HSA and drug coverage, and what to do when you retire. This guide is the starting point; the linked guides go deeper on each piece.
The decisions you face at 65 if you're still working
- Part A: most people pay no premium for it, so many take it at 65. The exception is if you (or your employer) contribute to an HSA.
- Part B: whether you can safely delay depends on your employer's size and whether the coverage comes from current work.
- Part D: you can delay if your job's drug coverage is "creditable."
- Your HSA: contributions must stop once any part of Medicare starts.
- Retirement: special enrollment periods let you sign up later without penalties, but the deadlines are strict.
Why employer size matters: the 20-employee rule
| Your (or your spouse's) employer | Who pays first at 65 | What it usually means |
|---|---|---|
| 20 or more employees | The job-based plan pays first; Medicare pays second | You can usually delay Part B without penalty. Many people take premium-free Part A and delay Part B. |
| Fewer than 20 employees | Medicare pays first; the job-based plan pays second | Sign up for Part A and Part B at 65. If you don't, the job plan may pay only what it would have paid after Medicare. |
If you work for a small Oregon business and skip Part B, the employer plan may pay only a small part of a claim, and you could owe a Part B late penalty when you sign up later. Ask the plan in writing who pays first. COBRA, retiree coverage, Marketplace plans and individual policies are not coverage from current employment. See employer plan and Medicare coordination.
If you have an HSA
- Any part of Medicare ends contributions, including premium-free Part A alone.
- The 6-month lookback: if you sign up for Part A after 65, coverage starts up to 6 months before you apply (not before your 65th-birthday month). Contributions for those months become excess contributions, taxed 6% a year until removed.
- Social Security triggers Part A: getting Social Security benefits enrolls you in Part A automatically.
Medicare.gov's advice is to stop HSA contributions 6 months before you sign up. For 2027, the HSA limit is $4,500 for self-only coverage and $9,000 for family coverage, plus $1,000 if you are 55 or older, prorated in the year Medicare starts. Full detail: HSAs and Medicare in Oregon.
Should you take Part A at 65?
If you or your spouse worked about 10 years paying Medicare taxes, Part A has no premium. Reasons to take it at 65:
- You don't contribute to an HSA.
- It can pay second after your job's plan for hospital stays.
Reasons to wait:
- You or your employer contribute to an HSA and you want to continue.
- You aren't getting Social Security yet (if you are, Part A is automatic).
The Part B special enrollment period
If you delayed Part B because of coverage from your or your spouse's current job, you can sign up any time while you still have that coverage, or during the 8 months that begin the month after the job or the coverage ends, whichever comes first. No late penalty applies.
- Send Social Security Form CMS-40B (the Part B application) and Form CMS-L564, with Section B completed by your employer.
- Coverage generally starts the month after you sign up. If you sign up while still covered by the job, or in the first full month after it ends, you can ask for a start up to 3 months later so it lines up with the end of your job coverage.
- COBRA doesn't extend the 8 months. Many people miss the window because they wait for COBRA to run out.
- Your one-time Medigap open enrollment period starts when Part B starts, if you are 65 or older.
Full detail: the Part B special enrollment period in Oregon.
Part D and creditable coverage
You can delay Part D without a penalty as long as you have creditable drug coverage, meaning it is expected to pay, on average, at least as much as standard Part D. Your plan must tell you each year before October 15. When that coverage ends, you have 2 full months to join a Part D plan or a Medicare Advantage plan with drug coverage.
If you go 63 days or more in a row without creditable coverage after your first chance to enroll, you may owe a Part D late penalty for as long as you have Part D: 1% of the national base beneficiary premium ($41.33 in 2027) for each full month without coverage, so about $0.41 a month for every uncovered month. Full detail: Part D creditable coverage in Oregon.
Timing your retirement around Medicare
- Retire at 65: sign up during your 7-month Initial Enrollment Period around your 65th birthday month.
- Retire later: use your 8-month Part B special enrollment period and 2-month Part D window when the job coverage ends.
- Social Security: you can start it any time from 62; there is no requirement to claim at 70, but delayed retirement credits stop growing at 70. Starting it enrolls you in Part A.
- A spouse on your plan: when your job coverage ends, a spouse who is 65 or older has the same special enrollment periods; a younger spouse needs other coverage. See spouse on an employer plan.
Full detail: retiring at 66, 67, 68 or 70 in Oregon.
Oregon-specific notes
- State and school employees: PEBB retiree medical coverage ends the last day of the month before the month you become eligible for Medicare (OAR 101-050-0010), and OEBB early-retiree medical coverage ends the last day of the month before your Medicare effective date (OAR 111-050-0015). See PEBB and Medicare and OEBB and Medicare.
- PERS retirees: the PERS Retirement Health Insurance Account subsidy requires you to be enrolled in both Part A and Part B (OAR 459-035-0030).
- Medigap in Oregon: after your Medigap open enrollment period, Oregon's birthday rule lets you switch to a plan with the same or fewer benefits each year, from 30 days before to 30 days after your birthday (OAR 836-052-0143). See Medigap in Oregon.
- Where you live: Medicare Advantage choices vary a lot by county; there is no plan open to everyone in Grant, Harney, Lake, Umatilla or Union counties for 2027. See your county.
- Help: Social Security, 1-800-772-1213 (TTY 1-800-325-0778), handles Part A and Part B sign-up. 1-800-MEDICARE (1-800-633-4227) answers coverage questions. To compare plans from the companies they work with, you can request a call from a licensed insurance agent.
Guides for each situation
- HSAs and Medicare: the 6-month Part A lookback
- Employer plan coordination: the 20-employee rule, COBRA and retiree coverage
- The Part B special enrollment period: Form CMS-L564 and the 8-month window
- Part D creditable coverage: the yearly notice and the 2-month window
- Spouse on an employer plan
- Retiring at 66, 67, 68 or 70
- Do I need Medicare Part B if I'm still working in Oregon?
Sources
- Medicare.gov — Working past 65
- Medicare.gov — Which insurance pays first
- Medicare.gov — When does Medicare coverage start?
- CMS — Form CMS-L564, Request for Employment Information
- Medicare.gov — Creditable drug coverage
- Medicare.gov — Avoid late enrollment penalties
- CMS — 2027 Part D base beneficiary premium (July 28, 2026)
- IRS — Publication 969, Health Savings Accounts
- Social Security — Delayed retirement credits
- Or. Admin. Code § 101-050-0010, PEBB retiree coverage (via Cornell LII)
- Or. Admin. Code § 111-050-0015, OEBB early retiree coverage (via Cornell LII)
- Or. Admin. R. 459-035-0030, PERS RHIA eligibility (Oregon.public.law)
- Or. Admin. Code § 836-052-0143, Oregon Medigap birthday rule (via Cornell LII)
Frequently asked questions
Can I delay Medicare if I'm still working at 65 in Oregon?
If you have group coverage from your or your spouse's current job and the employer has 20 or more employees, you can usually delay Part B without a penalty. If the employer has fewer than 20 employees, Medicare generally pays first and you should sign up for Part A and Part B at 65.
Can I keep contributing to my HSA after 65?
Only if you haven't enrolled in any part of Medicare, including Part A. Taking Social Security enrolls you in Part A automatically, and Part A can start up to 6 months before you sign up, so Medicare.gov advises stopping HSA contributions 6 months before you enroll.
Does COBRA count as job-based coverage for delaying Part B?
No. Medicare says COBRA doesn't extend your time to sign up. Your 8-month special enrollment period starts the month after your job or your job-based coverage ends, whichever is first, even if you choose COBRA.
What is Form CMS-L564?
It is the Request for Employment Information. Your employer completes Section B to confirm your group health coverage based on current employment. You send it to Social Security with the Part B application, Form CMS-40B, to sign up in a special enrollment period without a penalty.
How do I know if my employer drug coverage counts for Part D?
Your plan must tell you each year, before October 15, whether its drug coverage is creditable (expected to pay at least as much as standard Part D). Keep these notices. With creditable coverage you can delay Part D without a penalty, and you have 2 months after it ends to join a plan.
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