Leaving an employer plan at 67 or 70 is the most forgiving Medicare timing situation, but only if you document it correctly. Federal rules let anyone who delayed Part B because of coverage from current employment enroll in a Special Enrollment Period (SEP) that runs for 8 months after the job or the coverage ends, whichever ends first. That window has no age ceiling. A 70-year-old and a 67-year-old get the same 8 months, the same lack of penalty, and the same paperwork. The risk is not the age. The risk is assuming that your old coverage qualified when it did not. Retiree plans, COBRA, and ACA Marketplace plans do not count under Medicare.gov rules, and an employer with fewer than 20 employees usually makes Medicare the primary payer from age 65. In those cases, the 2026 Part B premium of $202.90/month carries a late penalty that you will pay for as long as you have Part B.
Medicare enrollment at this stage has four moving parts that run on different clocks: Part B (8 months), Part D (63 days), Medigap (6 months from Part B start), and Part A (premium-free for most people, with up to 6 months of retroactive coverage). This guide gives the exact dates for a 2026 departure, the 7 steps to file Form CMS-40B with the employer-completed Form CMS-L564 at ssa.gov, a comparison of COBRA against Medicare, and the income thresholds that decide whether Medicaid or a Medicare Savings Program pays your premiums. For the broader retirement version of this question, see Medicare Part B when retiring, and use the Medicare eligibility guide to confirm you qualify for premium-free Part A. Every dollar figure here is a 2026 figure from cms.gov, medicare.gov, or aspe.hhs.gov, and every deadline example is built on a 2026 departure date so you can count the months on your own calendar.
7 Steps to Get Coverage
Common Mistakes That Cost People Thousands
Most penalties in this situation come from one of five avoidable mistakes made in the months around a 2026 departure.
- Assuming COBRA or retiree coverage pauses the 8-month Part B SEP. Medicare.gov states that COBRA does not change when the SEP ends, so a 2026 COBRA election can burn the window.
- Waiting for Social Security to enroll you automatically. Auto-enrollment applies only if you already collect benefits, so a person who delays benefits to 70 still has to file Form CMS-40B.
- Counting employer coverage from a company with fewer than 20 employees. Medicare is usually primary there from age 65, and the 2026 Part B penalty is 10% of $202.90 per full 12 months of delay.
- Letting 63 days pass without creditable drug coverage. Part D penalties accrue at 1% of the $38.99 national base premium (2026) for each uncovered month and last as long as you have Part D.
- Contributing to an HSA after Part A starts. Part A can reach back 6 months, so contributions in that stretch can trigger IRS excess-contribution taxes.
Penalty Math for Waiting Until 67 or 70 in 2026
Part B penalty math in 2026 depends on whether a Special Enrollment Period covers your delay. Without an SEP in 2026, Medicare adds 10% of the standard premium for each full 12-month period you could have enrolled but did not. The 2026 standard premium is $202.90/mo, so a person who waited from age 65 to age 70 without qualifying coverage owes 5 periods, or 50%, which adds about $101.45/mo (roughly $1,217 per year) for life. A person who waited from 65 to 67 owes 20%, or about $40.58/mo in 2026. With a valid SEP, both owe 0% in 2026. The Part D penalty works differently: 1% of the $38.99 national base premium (2026) per full uncovered month, so 24 months without creditable drug coverage adds about $9.40/mo in 2026. Medicare Advantage does not remove either penalty. Medicare.gov and cms.gov publish the current figures, and the Part D penalty is waived for people who receive Extra Help.
Medicaid and Medicare Savings Programs After You Leave Work in 2026
Medicaid and Medicare Savings Programs (MSPs) often become available when a paycheck stops, because eligibility looks at current monthly income. The Qualified Medicare Beneficiary (QMB) program pays the $202.90/mo Part B premium (2026) and cost sharing for people near 100% of the Federal Poverty Level, which is $15,960 for one person in 2026. The Medicaid expansion line is 138% FPL, or $22,025 for one person in 2026, in the 40 expansion states plus DC. State brands include Medi-Cal in California, MassHealth in Massachusetts, AHCCCS in Arizona, TennCare in Tennessee, and Apple Health in Washington. Apply through your state Medicaid agency at any time, since Medicaid has no enrollment deadline per medicaid.gov. Many states also enroll QMB members in Part B outside the SEP through a state buy-in. Check the table above for your household size, and see Medicaid income limits and the Federal Poverty Level page for current figures.
Why Each Document Matters for a 2026 Part B Special Enrollment Period
Social Security uses Form CMS-L564 to confirm two facts: that you were covered under a group health plan based on current employment during every month after you became eligible for Part B, and when that coverage or employment ended. The employer completes Section B, so request it before your last day, while HR still has your records. The HR coverage letter backs up the dates and lets you request a Part B start date up to 3 months later when you file inside the first full month after coverage ends. The creditable coverage notice protects you from a Part D penalty. The 2024 tax return supports an IRMAA reduction request on Form SSA-44, since the 2026 surcharge begins above $109,000 for one filer or $218,000 for joint filers per the CMS 2026 fact sheet. If you had a Marketplace plan, keep Form 1095-A for tax reconciliation of premium tax credits. Social Security will not guess at missing dates, so a complete packet avoids weeks of back-and-forth.
Age 67 vs Age 70: What Changes and What Does Not in 2026
Age 67 and age 70 differ for Social Security, not for Medicare. Full retirement age is 67 for people born in 1960 or later, and each year of delay past it adds delayed retirement credits until age 70, so many workers stay employed and keep employer coverage through those years. Medicare eligibility starts at 65 regardless, and the Part B SEP works the same at 67, 70, or older. Social Security benefits and Medicare are separate applications: delaying benefits to 70 does not delay Medicare, but it also means Social Security will not auto-enroll you in Part B. If you apply for Social Security after 65, Part A is retroactive up to 6 months, which is why HSA contributions must stop first. Once you collect benefits, the Part B premium of $202.90/mo (2026) is deducted from your monthly payment. Review ssa.gov for your benefit estimate, and compare it with Medicare eligibility rules before choosing a retirement month.
Frequently Asked Questions
What is the Part B Special Enrollment Period when I leave my employer plan at 67 or 70?
Your Part B Special Enrollment Period lasts 8 months and starts the month after your employment or your employer group coverage ends, whichever ends first. In 2026, a June 30 departure gives you July 1, 2026 through February 28, 2027. The window is the same at 67, 70, or any older age, and it requires that your coverage was based on current employment at an employer with 20 or more employees. File Form CMS-40B and Form CMS-L564 with Social Security through ssa.gov or at 1-800-772-1213. Medicare.gov confirms the 8-month rule and that COBRA does not change it.
How do I document leaving my employer plan for the Part B SEP?
Document the SEP with Form CMS-40B (your application) and Form CMS-L564 (employment information completed by your employer). Add an HR letter with your last day of work and your coverage end date, plus proof of age such as a birth certificate. Request the employer section before your last day, because HR can respond faster while you are still on payroll. Submit the packet to your local Social Security office or by calling 1-800-772-1213 in 2026. Keep copies of every page and the date you submitted them in case Social Security asks for corrections.
What if I miss the 8-month window after leaving my employer plan?
Missing the 8-month SEP means you wait for the General Enrollment Period, January 1 through March 31 each year, and coverage starts the month after you sign up. Part B then carries a penalty of 10% for each full 12-month period you could have enrolled, added to the 2026 premium of $202.90/mo for as long as you have Part B. A 5-year delay costs about $101.45/mo in 2026. You also face a coverage gap, since no Marketplace SEP or COBRA election restores the Part B window. Medicaid or a Medicare Savings Program through your state agency can help if your income is low.
Can I get retroactive coverage when I enroll in Medicare after leaving my employer plan?
Retroactive coverage depends on the Medicare part. Part A, if premium-free, can reach back up to 6 months from your application, but never before the month you became eligible. Part B under the SEP generally starts the first of the month after you enroll, with an option to delay the start up to 3 months. Part B is not retroactive in 2026. Because Part A can be retroactive, stop HSA contributions at least 6 months before you apply, per IRS Publication 969. Medicaid may cover up to 3 months of past medical bills in some states if you apply promptly.
What is the difference between COBRA and Medicare after leaving an employer plan at 67 or 70?
COBRA is continuation of your old employer plan at 102% of the full premium, typically $400 to $900/mo for an individual in 2026, for 18 to 36 months. Medicare Part B costs $202.90/mo in 2026 and works with Part D and Medigap or Medicare Advantage. COBRA does not count as current-employment coverage, so electing it does not pause the 8-month Part B SEP. At 65 or older with Medicare, COBRA often pays second, which makes it a poor substitute for Part B. COBRA's election window is 60 days, which runs alongside the Part B clock, not instead of it.
What state-specific rules apply when I leave my employer plan at 67 or 70?
Federal Part B SEP rules apply in every state, but state rules change your next-step options. New York and Connecticut require year-round Medigap open enrollment, which softens a late Medigap start. California uses a birthday rule with a 90-day window for switching Medigap plans. Medicare Savings Programs and Medicaid use state brands such as Medi-Cal, MassHealth, and AHCCCS, and income limits and buy-in timing vary. Check your state Medicaid agency and your State Health Insurance Assistance Program (SHIP) for free counseling in 2026.
Do I qualify for Medicaid or help with Medicare costs after I leave work?
You qualify when your current monthly income is within your state limits, which can happen quickly after retirement. In 2026, the Medicaid expansion line is 138% of the Federal Poverty Level, or $22,025 for one person and $29,863 for two. Qualified Medicare Beneficiary (QMB) pays the $202.90/mo Part B premium (2026) near 100% FPL, or $15,960 for one person. Extra Help lowers Part D costs and waives the Part D penalty. Apply any time through your state Medicaid agency, as medicaid.gov confirms there is no enrollment deadline.
Does delaying Social Security to 70 delay Medicare?
Delaying Social Security to 70 does not delay Medicare, which is a separate application. Social Security auto-enrolls you in Parts A and B only if you already collect benefits before 65. If you work past 65 with employer coverage, you can delay Part B and use the 8-month SEP later, but you must still apply by filing Form CMS-40B. Premium-free Part A is worth taking, but pause HSA contributions first. In 2026, once you collect benefits the $202.90/mo Part B premium is deducted from your payment.
