If you already have Medicare because of a disability, turning 65 does not end or restart your coverage. Your Part A and Part B carry forward automatically, you keep the same Medicare card, and Social Security handles the transition without any paperwork from you.1Social Security Administration. Medicare What changes is the reason you qualify: your eligibility basis shifts from disability to age. That shift is quiet on paper, but it unlocks several new rights worth using.
Medigap Finally Opens Up
This is the biggest practical change at 65. Federal law does not require insurance companies to sell Medigap policies to Medicare beneficiaries under 65. Some states require it and some don’t, and where policies are available to younger disability beneficiaries, premiums tend to run much higher.2Medicare. When Can I Buy a Medigap Policy?
When you turn 65, you get a six-month Medigap Open Enrollment Period that begins the first day of the month you are both 65 and enrolled in Part B. During this window, insurers cannot deny you any Medigap policy they sell, cannot charge more because of pre-existing conditions, and cannot impose waiting periods.3Medicare. Get Ready to Buy It is a one-time window that does not repeat.
If you went without a supplement during your disability years because you couldn’t get one at a reasonable price, this is your chance to lock in standard rates. If you already bought a Medigap policy under 65 at higher premiums, you can shop again during this window and likely pay less.
Your Part D Late Enrollment Penalty Resets
If you built up a Part D late enrollment penalty during your under-65 years because you went 63 or more consecutive days without creditable drug coverage, that penalty is eliminated when you turn 65. The reset is specific to disability beneficiaries transitioning to age-based Medicare, so you effectively get a clean slate for Part D.
The standard Part D penalty is 1% of the national base beneficiary premium for each month you were eligible but didn’t have creditable coverage, and it normally lasts as long as you have Medicare drug coverage.4Medicare. Creditable Prescription Drug Coverage After 65, if you go without creditable coverage again, a new penalty starts building from that point forward.
You Get a New Initial Enrollment Period
Turning 65 gives you a fresh Initial Enrollment Period even though you already have Medicare. It runs for seven months: the three months before your 65th birthday month, the birthday month itself, and the three months after.5Medicare. When Does Medicare Coverage Start? During this window you can:
- Enroll in a Part D plan without penalty.
- Join a Medicare Advantage plan, since you already have Part A and Part B.
- Switch between Medicare Advantage and Original Medicare.
- Buy a Medigap policy under the guaranteed-issue protections described above.
If your Initial Enrollment Period passes and you want to make plan changes later, the Annual Enrollment Period from October 15 through December 7 lets you switch Medicare Advantage plans, move between Advantage and Original Medicare, or change Part D plans, with changes taking effect the following January 1.6Centers for Medicare & Medicaid Services. Medicare Open Enrollment
What Happens to Your Premiums
If you were already paying Part B premiums on disability, you’ll keep paying them at 65. The amounts may shift slightly because CMS resets rates each year, but the structure is the same. The standard Part B premium in 2026 is $202.90 per month.7Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
Most people pay nothing for Part A because they or a spouse paid Medicare taxes for at least 10 years (40 quarters). If you don’t meet that threshold, the 2026 Part A premium is $311 per month with 30 to 39 quarters, or $565 per month with fewer than 30.8Medicare. Costs
If your modified adjusted gross income from two years earlier exceeds $109,000 as a single filer or $218,000 filing jointly, you’ll pay an Income-Related Monthly Adjustment Amount (IRMAA) on top of the standard Part B premium, pushing costs as high as $689.90 per month at the top tier. IRMAA also applies to Part D premiums at the same thresholds.9Centers for Medicare & Medicaid Services. 2026 Medicare Parts B Premiums and Deductibles
Appealing IRMAA
Because IRMAA looks back two years, it can be unfairly high if your income has dropped since then. Qualifying life-changing events include stopping work, reducing hours, losing a pension, divorce, or losing a spouse. File Form SSA-44 with supporting evidence (a signed employer statement, pay stubs, or similar) to ask Social Security to use your more recent income.10Social Security Administration. Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event The form can be mailed, faxed, or uploaded through your my Social Security account.11Social Security Administration. Request to Lower an Income-Related Monthly Adjustment Amount
If You Have Employer Coverage, the Rules Change
When you’re covered by a group health plan through current employment (yours or a spouse’s), Medicare Secondary Payer rules decide which plan pays first. During your under-65 disability years, the threshold was 100 employees: at employers with 100 or more, the group plan paid first and Medicare paid second.
At 65, that threshold drops to 20 employees. Group plans at employers with 20 or more workers pay first; Medicare pays first when the employer has fewer than 20.12Centers for Medicare & Medicaid Services. Medicare Secondary Payer (MSP) Overview13Centers for Medicare & Medicaid Services. Small Employer Exception That change can flip whether Medicare or your employer plan is your primary insurance, so it’s worth confirming with your benefits administrator around your 65th birthday. Liability and no-fault insurance always pays before Medicare, regardless of employer size.14Medicare.gov. Who Pays First?
Your SSDI Doesn’t Convert Yet
Age 65 is a Medicare milestone, not a Social Security one. Your SSDI payments continue as SSDI until you reach full retirement age, which is 67 for anyone born in 1960 or later.15Social Security Administration. If I Get Social Security Disability Benefits and I Reach Full Retirement Age, Will I Then Receive Retirement Benefits? The switch to retirement benefits then happens automatically and the payment amount stays the same, because both benefits are calculated from the same formula.16Social Security Administration. What You Need to Know When You Get Social Security Disability Benefits If you receive a reduced surviving spouse benefit along with SSDI, contact Social Security when you reach full retirement age so they can adjust the amounts correctly.
Help With Costs If Your Income Is Limited
If your income is low, a Medicare Savings Program can cover premiums and cost-sharing. The Qualified Medicare Beneficiary (QMB) program is the most comprehensive, paying Part A and Part B premiums, deductibles, copayments, and coinsurance.17Medicare. Medicare Savings Programs Other tiers pay only premiums or only Part B costs.
Income and asset limits vary by state, and monthly income limits for individuals generally fall between roughly $1,350 and $2,015 depending on the program and location. Some states have dropped asset tests entirely. You apply through your state Medicaid office, and it’s worth applying even if you think you’re slightly over the limit, because many states use income disregards that raise the effective thresholds.