When Can I Enroll in Medicare in CT? 2026 Enrollment Periods

Medicare in Connecticut is not a one-time enrollment — it’s a system of overlapping windows, each with its own purpose, deadline, and penalty for missing it. The federal government sets seven primary enrollment periods, and Connecticut adds a unique ‘Birthday Rule’ for Medigap that exists in only a handful of states. Get the timing right and you walk into retirement with the coverage you want, no penalties, no gaps. Get it wrong and you can face Part B premiums that are 30%, 50%, even 100% higher for the rest of your life, a Part D penalty that compounds every month you delay, or a months-long gap with no drug coverage. This 2026 guide walks every Connecticut resident through every enrollment window — Initial Enrollment Period, General Enrollment Period, Annual Election Period, Medicare Advantage Open Enrollment, Medigap Open Enrollment, the Connecticut Birthday Rule, and every Special Enrollment Period — with exact 2026 CMS dates, the precise late-enrollment penalty math, and the most common mistakes Connecticut residents make at 65.

Initial Enrollment Period (IEP) — The 7-Month Window at 65

The Initial Enrollment Period is the first time most Connecticut residents become eligible for Medicare. It is exactly 7 months long: it begins 3 months BEFORE the month you turn 65, includes your birthday month, and continues for 3 months AFTER. For example, if you turn 65 on July 14, 2026, your IEP runs April 1, 2026 through October 31, 2026. During the IEP you can enroll in Medicare Part A (hospital), Part B (outpatient), a Medicare Advantage plan (Part C), and/or a stand-alone Part D drug plan with no medical underwriting and no late-enrollment penalty. The 7-month window applies regardless of whether you are still working, drawing Social Security, or fully retired.

The ‘best sign-up window’ is the first 3 months of your IEP — the ones BEFORE your birthday month. Enrolling early ensures your Medicare card arrives before your 65th birthday and your coverage starts on the first day of your birthday month with no delay. Waiting until your birthday month or after pushes the effective date later, which can create a coverage gap if you’re losing employer coverage on or near your 65th birthday.

When IEP Coverage Actually Starts — 2026 Rules

As of January 1, 2023 (still in effect for 2026 under the Consolidated Appropriations Act 2021), Medicare effective dates were simplified. If you enroll during the FIRST 3 MONTHS of your IEP (before your birthday month), Part A and Part B coverage starts on the first day of your birthday month. If you enroll DURING your birthday month OR any of the 3 months AFTER, coverage starts the FIRST DAY OF THE FOLLOWING MONTH. This eliminated the old ‘up to 3-month delay’ that used to penalize people who signed up late in their IEP — but it also means waiting until after your birthday creates at least a 1-month coverage gap.

General Enrollment Period (GEP) — January 1 to March 31, 2026

If you missed your IEP and don’t qualify for a Special Enrollment Period, the General Enrollment Period is your annual chance to sign up for Medicare Part A and/or Part B. The GEP runs January 1 – March 31 every year, including 2026. As of January 1, 2023, GEP coverage starts the FIRST DAY OF THE MONTH AFTER you enroll — for example, sign up February 15, 2026, coverage starts March 1, 2026. This is a major improvement over the old rule that delayed GEP coverage all the way to July 1. However, signing up through the GEP almost always triggers the Part B late-enrollment penalty (10% per full 12-month period you could have had Part B but didn’t), which sticks with you for life. The GEP is a safety net, not a planning tool — never miss your IEP if you can avoid it.

Annual Election Period (AEP) — October 15 to December 7, 2026

The Annual Election Period is the most well-known Medicare window — it runs October 15, 2026 through December 7, 2026. During AEP, anyone already enrolled in Medicare can: (1) join, switch, or drop a Medicare Advantage plan (Part C); (2) join, switch, or drop a stand-alone Part D prescription drug plan; (3) switch from Original Medicare to a Medicare Advantage plan or vice versa. All changes made during AEP take effect January 1, 2027. AEP is the right window to compare Connecticut’s Medicare Advantage plans (Aetna, Anthem, ConnectiCare, Cigna, UnitedHealthcare, WellCare, Humana, etc.) and stand-alone Part D plans (SilverScript, Wellcare, Humana Walmart, Aetna SilverScript, etc.) because every plan publishes its 2027 premiums, formulary, network, copays, and Star Ratings by October 1 each year.

Medicare Advantage Open Enrollment Period (MA-OEP)

Separate from AEP, the Medicare Advantage Open Enrollment Period runs January 1 – March 31 every year. MA-OEP gives anyone already enrolled in a Medicare Advantage plan ONE opportunity to: (1) switch to a different Medicare Advantage plan, or (2) drop their MA plan and return to Original Medicare (with the option to add a stand-alone Part D drug plan). MA-OEP is one switch only — you cannot ‘try out’ multiple plans during MA-OEP. It does NOT apply to people in Original Medicare; if you have Original Medicare on January 1, you cannot use MA-OEP to switch INTO an MA plan (you’d need AEP, an SEP, or your IEP).

Medigap Open Enrollment Period — The Most Important 6 Months of Your Life

Your Medicare Supplement (Medigap) Open Enrollment Period is a ONE-TIME, 6-month window that begins the first day of the month you are BOTH age 65 OR older AND enrolled in Medicare Part B. During this window, any Medigap insurance carrier in Connecticut MUST sell you any Medigap policy they offer at the best available rate, regardless of your health history. No medical underwriting. No pre-existing condition exclusions. No rate-up for being a diabetic, cancer survivor, or heart patient. Outside this 6-month window, Connecticut insurers can require medical underwriting and decline applications based on health (with limited exceptions including the Connecticut Birthday Rule and federal Guaranteed-Issue rights).

Connecticut Birthday Rule — Switch Medigap Plans Every Year With No Underwriting

Connecticut is one of only a handful of states (alongside California, Oregon, Washington, Idaho, Illinois, Kentucky, Louisiana, Maryland, Missouri, Nevada, and Oklahoma) with a ‘Birthday Rule’ that gives existing Medigap policyholders a second chance EVERY YEAR to switch to a different Medigap plan with NO medical underwriting. In Connecticut, the Birthday Rule window opens on your birthday and continues for 60 days afterward. During this window, you can switch to an equal or lesser benefit Medigap plan from any carrier without going through health questions. The new plan must be of equal or lower benefit level than your current one — for example, you can move from Plan G to Plan N (lesser benefits), but not from Plan N to Plan G.

Why does this matter financially? Medigap plans become more expensive every year as you age. A Plan G that costs $185/month at age 65 might cost $310/month at age 75 with the same carrier. Switching to a newly-priced policy from a different carrier — especially during your Birthday Rule window — can save Connecticut seniors $40-$100/month, often $500-$1,200/year. Without the Birthday Rule, most insurers would refuse to write you a new policy due to health changes. With it, you can shop annually for the lowest Plan G or Plan N premium in Connecticut and lock in those savings for the next 12 months.

Special Enrollment Period — Losing Employer or Union Health Coverage

If you delayed Part B because you (or your spouse) had active employer or union coverage past age 65, you qualify for a Special Enrollment Period to sign up for Part B without penalty when that coverage ends. The SEP lasts 8 months and begins the month AFTER your employment ends OR the month AFTER your employer coverage ends (whichever is first). For example, if you retire on June 30, 2026 and your employer plan ends June 30, your Part B SEP runs July 1, 2026 – February 28, 2027. To use this SEP, you must complete CMS Form L564 (Request for Employment Information) signed by your former employer, plus CMS Form 40-B (Application for Enrollment in Medicare Part B). COBRA does NOT count as active employer coverage for SEP purposes — only ACTIVE current employment qualifies you to delay Part B without penalty.

Special Enrollment Period — Moving In, Out, or Within Connecticut

If you have a Medicare Advantage plan or Part D drug plan and move outside your plan’s service area (or to a new area where new plans are available), you qualify for an SEP to switch plans. The SEP starts the month BEFORE your move (if you notify your plan in advance) or the month of your move and lasts 2 full months after. In Connecticut, this matters most when moving between counties because plan networks (hospital systems, primary-care groups, specialists) vary significantly — Hartford HealthCare dominates Hartford County, Yale New Haven Health dominates New Haven County, Nuvance Health is strong in Fairfield/Litchfield. A plan that was perfect for you in Stamford may have a poor provider network in Manchester. Always re-evaluate your plan when you move.

Special Enrollment Period — Qualifying for HUSKY C or Extra Help

Connecticut Medicare beneficiaries who qualify for Medicaid (HUSKY C in Connecticut) and/or the federal Extra Help (Low-Income Subsidy / LIS) program for Part D get powerful enrollment flexibility: a quarterly SEP allowing them to change Medicare Advantage or Part D plans once per quarter during Q1, Q2, and Q3 (January – September). Effective 2025 and continuing in 2026, full-dual-eligible beneficiaries (those with both full Medicaid and Medicare) get a MONTHLY SEP to switch from a Medicare Advantage plan to Original Medicare with a stand-alone Part D plan. This is especially valuable in Connecticut, which has aggressive HUSKY C asset and income limits — even modest pension income can disqualify you, but if you do qualify, you have year-round plan flexibility.

5-Star Special Enrollment Period — December 8 to November 30

CMS publishes annual Star Ratings (1-5 stars) for every Medicare Advantage and Part D plan based on quality, customer service, and clinical outcomes. If a 5-Star Medicare Advantage, Part D, or MA-PD plan is offered in your Connecticut zip code, you can switch INTO that 5-star plan ONCE per year using the 5-Star Special Enrollment Period, which runs December 8 through November 30. The change is effective the first day of the month after enrollment. In Connecticut, 5-star plans are relatively rare — most years, only one or two MA-PD plans in the state earn 5 stars. Use a free Plan Finder tool or work with a Connecticut Medicare broker to check the current 5-star options in your zip code.

Other Special Enrollment Periods You Should Know

Additional 2026 SEPs Connecticut Medicare Beneficiaries Should Know

• Plan termination / non-renewal: if your Medicare Advantage or Part D plan exits the Connecticut market, you have a 3-month SEP from notification through the end of February of the new year.
• Loss of creditable drug coverage: 2-month SEP after losing creditable Part D drug coverage (e.g., losing employer Rx coverage that was at least as good as Part D).
• Returning to the US after living abroad: 2-month SEP to enroll in Medicare Advantage or Part D.
• Release from incarceration: 2-month SEP to enroll in Medicare Advantage or Part D after release.
• Skilled Nursing Facility (SNF) residents: monthly SEP while in an SNF, plus 2 months after leaving.
• Plan misrepresentation or CMS sanction: case-by-case SEP granted by CMS.
• Federally-declared disaster (FEMA): SEP for affected zip codes; Connecticut has triggered this for major storms (Tropical Storm Isaias 2020, severe storms 2024).
• Chronic condition Special Needs Plan (C-SNP) eligibility: anytime you newly qualify for a C-SNP based on a diagnosed chronic condition like diabetes, cardiovascular disease, COPD.

Part B Late Enrollment Penalty — 10% per Year, For Life

The Part B late-enrollment penalty is one of the most painful — and permanent — penalties in the entire Medicare system. If you go 12 or more full months without Part B after your IEP ends (and you don’t qualify for an SEP), CMS adds 10% to your Part B premium for each full 12-month period you could have had Part B but didn’t. The penalty stays with you for as long as you have Medicare Part B — usually for the rest of your life. The 2026 standard Part B premium is approximately $185/month, so a 30% penalty adds $55.50/month, or $666/year, every year forever.

Part D Late Enrollment Penalty — 1% per Month, For Life

The Part D late-enrollment penalty applies if you go 63 or more days without creditable prescription drug coverage after your IEP ends. The penalty is calculated as 1% of the ‘national base beneficiary premium’ for each FULL MONTH you went without creditable coverage. The 2026 national base beneficiary premium is approximately $36.78/month, so each month late adds about $0.37/month to your Part D premium — for the rest of your life. Two years late = 24% × $36.78 = $8.83/month extra. The penalty is recalculated each year as the national base premium changes, and it follows you between Part D plans (including if you join a Medicare Advantage Prescription Drug plan).

Who Gets Automatically Enrolled in Medicare?

Most Connecticut residents are NOT automatically enrolled in Medicare at 65 — you must actively apply. The exceptions: (1) if you are already receiving Social Security retirement benefits or Railroad Retirement Board benefits for at least 4 months before your 65th birthday, you are automatically enrolled in BOTH Part A and Part B effective the first day of your birthday month, and your red, white, and blue Medicare card arrives by mail approximately 3 months before your 65th birthday. (2) If you are under 65 and have been receiving Social Security Disability Insurance (SSDI) for 24 months, you are automatically enrolled in Medicare effective the 25th month. (3) People with ALS (Lou Gehrig’s disease) are automatically enrolled in Medicare immediately when SSDI benefits begin — no 24-month wait. (4) People with End-Stage Renal Disease (ESRD) have a separate enrollment process tied to their dialysis or transplant start date.

If you’re auto-enrolled and don’t want Part B (typically because you have active employer coverage), you must follow the instructions on the back of your Medicare card to OPT OUT of Part B within the deadline. If you take Part A only and decline Part B at 65 while working past 65 with employer coverage, you can sign up for Part B later during an SEP without penalty when your employer coverage ends — provided you can document continuous active employer coverage with CMS Form L564.

Still Working at 65 — Should You Enroll in Medicare?

Whether to enroll in Medicare while still working past 65 depends on your employer’s size and the type of coverage. The rule: if your employer has 20 or more employees, the employer plan is primary and Medicare is secondary — you can usually safely delay Part B (and potentially Part A if your employer plan is an HSA-qualified high-deductible plan and you want to keep contributing to your HSA). If your employer has FEWER than 20 employees, Medicare becomes PRIMARY at 65 even if you have employer coverage — and if you don’t enroll in Part B, your employer plan may pay nothing on Medicare-covered services, leaving you with massive bills. Always check with your HR department in writing for small-employer rules.

How to Actually Enroll in Medicare — Step by Step

Three Ways to Enroll in Medicare in Connecticut (2026)

• Online at SSA.gov/medicare — fastest method, takes 10-15 minutes, available 24/7. Have your Social Security number, date of birth, and (if applicable) employer coverage details ready.
• By phone at 1-800-772-1213 (TTY 1-800-325-0778), Monday – Friday, 8 AM – 7 PM Eastern. Best for people who want to ask questions during enrollment.
• In person at a Social Security office — Hartford (960 Main Street), New Haven (150 Court Street), Bridgeport (3885 Main Street), Stamford (2 Landmark Square), Waterbury (51 North Elm Street), Norwich (2 Cliff Street), Danbury (131 West Street), Torrington (147 Litchfield Street), New London (2 Shaws Cove). Appointments strongly recommended — call ahead.
• Then enroll in Medicare Advantage or Part D online at Medicare.gov, by calling 1-800-MEDICARE, or — for free expert help — through a licensed Connecticut Medicare broker who is contracted with multiple carriers.

2026 Connecticut Medicare Calendar — Key Dates to Remember

Most Common Connecticut Medicare Enrollment Mistakes

Top 10 Medicare Enrollment Mistakes in Connecticut (Avoid These)

• Waiting until your birthday month or later to enroll during IEP — pushing your effective date back 1-4 months and creating a coverage gap.
• Assuming COBRA is creditable coverage for Part B — it is NOT; you must enroll in Part B when active employment ends, not when COBRA ends.
• Skipping Part D drug coverage at 65 because you
• t take any medications
• Letting your Medigap (Medicare Supplement) Open Enrollment Period close without applying for guaranteed-issue coverage, then trying to buy a plan later with health conditions.
• Not using Connecticut
• Choosing a Medicare Advantage plan in October without verifying your doctors and hospitals are in-network for the FOLLOWING year (networks change every January).
• Failing to check the formulary for your specific medications before switching Part D plans — Tier changes and formulary removals can dramatically increase your costs.
• Continuing HSA contributions after enrolling in any part of Medicare — triggering a 6% excess contribution tax.
• Auto-renewing the same MA-PD plan year after year without comparing — premiums, copays, networks, and benefits change every year.
• Not working with a licensed Connecticut Medicare broker who is contracted with multiple carriers — independent advice across plans is free to you and dramatically reduces the chance of an expensive mistake.

Frequently Asked Questions — 2026 Medicare Enrollment in Connecticut

Frequently Asked Questions