Glossary
General Enrollment Period (GEP)
The January 1 – March 31 window each year when you can sign up for Medicare if you missed your IEP and don't qualify for an SEP.
Also known as: General Enrollment, Medicare GEP
Quick answer
The General Enrollment Period runs January 1 through March 31 every year. It's the fallback enrollment path for anyone who missed their Initial Enrollment Period and doesn't qualify for a Special Enrollment Period. Since 2023, coverage begins the first of the month after you enroll (previously it was delayed until July).
Why it matters
GEP is the safety net — but it's expensive. Most retirees who use GEP owe a permanent Part B late-enrollment penalty, and any months you were without TFL between 65 and GEP enrollment were months you paid full price for civilian care.
Why this matters at age 65
If you reach age 65 without enrolling — for any reason — GEP is your only path back to TFL. Every full 12-month period you delay adds 10% to your Part B premium FOR LIFE. Don't wait. File the moment you realize Part B wasn't enrolled.
When you'll encounter it
Only if you missed IEP and aren't eligible for an SEP through active employer coverage.
Impact on Medicare
Coverage begins the first of the month after you enroll. Part B late-enrollment penalty is calculated and added to your premium permanently.
Impact on TRICARE For Life
TFL stays inactive until both Parts A and B become effective. Any gap between turning 65 and GEP enrollment is a gap in TFL — you pay full price for any civilian care during that time.
Common misconceptions
- "GEP coverage is retroactive to my 65th birthday." — It is not. Coverage starts the month AFTER you enroll, with no back-dating.
- "The Part B late penalty falls off after a few years." — It is permanent — for the rest of your life on Medicare.
Common mistakes to avoid
- Filing in late March and being surprised coverage doesn't start until April or May.
- Not realizing the penalty calculation counts FULL 12-month periods — even a 13-month delay = 10% penalty for life.
- Failing to enroll in Part D during GEP if you've also gone without creditable drug coverage.
Real-world scenario: A retired Navy chief turned 65 in June 2024 and skipped Part B 'because of VA care.' In February 2026 he is hospitalized at a civilian ER and discovers TFL was terminated.
He enrolls during GEP (Jan 1 – Mar 31, 2026). Coverage begins April 1, 2026. He owes a 20% Part B late penalty for life (two full 12-month periods missed). He also owes the entire civilian hospital bill out of pocket.
What should I do?
- 1If you missed IEP, file with Social Security in January — earlier in GEP means earlier coverage and less time without TFL.
- 2Confirm in writing whether SSA is assessing a Part B late penalty so you can verify the math.
- 3Once Medicare is effective, log into milConnect and confirm DEERS reflects both A and B dates.
- 4If you ALSO went without creditable drug coverage, evaluate whether to enroll in Part D during GEP — TRICARE Pharmacy is creditable, so most retirees should NOT enroll in Part D.
Questions people commonly ask
- How do I sign up if I missed my IEP?
- When will my coverage start if I enroll during GEP?
- Can I get the late-enrollment penalty waived?
Continue learning
— suggested by the knowledge graph- What is Medicare? A complete overview for retired militaryA plain-English, handbook-grounded overview of the federal health insurance program for people 65 and older, written specifically for retired service members and their families.
- Understanding Original Medicare (Parts A & B) for veteransExactly what Part A and Part B cover, what they cost in 2026, and why both are required to keep TRICARE For Life.
- Enrolling in Medicare: timing, methods, and the military-specific rulesWhen and how to sign up for Medicare Parts A and B — and the timing that protects your TRICARE For Life activation.
- Creditable CoverageNon-Medicare coverage that CMS deems at least as good as a standard Medicare Part D plan — TRICARE Pharmacy qualifies, so TFL beneficiaries don't need Part D.
- Creditable Drug CoveragePrescription drug coverage that CMS certifies is at least as good as standard Medicare Part D — including TRICARE Pharmacy and VA Pharmacy.
- Disability Medicare Eligibility (Under 65)Medicare eligibility before age 65 — automatic after 24 months of SSDI, immediately for ALS, and based on dialysis/transplant for ESRD.
- IRMAA (Income-Related Monthly Adjustment Amount)An income-based surcharge added to your Medicare Part B and Part D premiums when your modified adjusted gross income exceeds CMS thresholds.
- Medicare EligibilityU.S. citizens and lawful permanent residents (5+ years) qualify for Medicare at age 65, or earlier with qualifying disability or ESRD/ALS.
- Medicare Part D and TFLWhy TFL beneficiaries do not need (and usually should not enroll in) a standalone Medicare Part D plan.
- What is the Initial Enrollment Period (IEP)?The 7-month window around your 65th birthday — 3 months before, your birthday month, and 3 months after — when you first enroll in Medicare without penalty.
- I missed my Medicare enrollment window. Now what?Use the General Enrollment Period (Jan 1 – Mar 31). You'll likely owe a Part B late penalty for life, and you'll have no TFL until Part B is effective.
- What is the General Enrollment Period?January 1 – March 31 each year. It's the backup enrollment window for people who missed their IEP and don't qualify for a Special Enrollment Period.
- I'm turning 65. What should I do first?About 3 months before your 65th birthday, sign up for Medicare Parts A and B at SSA.gov. TRICARE For Life activates automatically once both are effective and DEERS is current.
- What is the 5-star Special Enrollment Period?A one-time-per-year chance (Dec 8 – Nov 30) to switch into a 5-star-rated Medicare Advantage or Part D plan in your area, outside the normal enrollment windows.
Related lessons
Related glossary terms
Related Official Resources
Continue learning straight from the source. Every link below goes to an official government or DoD resource.
Last reviewed January 2026 against the 2026 Medicare & You and TRICARE For Life handbooks.