Open Enrollment Calendar: Dates You Can't Afford to Miss
Almost every coverage problem we solve starts the same way: someone found out too late. Bookmark this page: here are the enrollment windows and what you can do in each one.
Updated on August 10, 2026 · 5 min read
The main windows of the year
| Period | Dates | What it's for |
|---|---|---|
| Medicare AEP (Annual Enrollment Period) | October 15 – December 7 | Switch between Original Medicare and Advantage, or change your Part D plan. Effective: January 1. |
| Obamacare / ACA – Open Enrollment | November 1 – January 15 (in Texas) | Enroll or switch Marketplace plans. For coverage to start January 1, you must enroll by December 15. |
| Medicare Advantage – Open Enrollment Period | January 1 – March 31 | If you're already on an Advantage plan: switch to another Advantage plan or return to Original Medicare with Part D. |
| Medigap – Guaranteed Issue Window | 6 months from when your Part B starts | Buy a supplement with no health questions. It doesn't repeat every year. |
| Medicare Initial Enrollment Period (IEP) | 3 months before, the month of your 65th birthday, and 3 months after | Enroll for the first time in Parts A, B, D and choose your path. |
Exact dates for the upcoming season
For 2027 coverage: Medicare AEP runs October 15 to December 7, 2026, and Marketplace open enrollment runs November 1, 2026 to January 15, 2027 in Texas.
Our practical tip: schedule your review in October. In November and December calendars fill up fast, and rushed decisions are the expensive ones.
Missed the date? Special Enrollment Periods (SEP)
Outside of open enrollment, you can still enroll if you had a qualifying life event. You usually have 60 days to act:
- You lost employer coverage or your parents' plan.
- You got married or divorced.
- You had a baby or adopted a child.
- You moved to another county or state (for example, you relocated to Katy or Houston).
- Your income changed significantly, or you gained a new eligible immigration status.
What to check before renewing, even if you're happy with your plan
Auto-renewal is convenient, but premiums, deductibles, networks, and drug lists change every year. A great plan this year could drop your doctor next year.
- Are your doctors and hospital still in-network?
- Are your medications still on the formulary at the same cost tier?
- Did your estimated income or household size change?
- What's the new plan's maximum out-of-pocket?
Questions we hear often
When does Obamacare open enrollment start in Texas?
November 1. It closes January 15, but for your coverage to start January 1 you must complete enrollment by December 15.
What happens if I do nothing during open enrollment?
On the Marketplace, your plan usually auto-renews with the new year's price and terms; with Medicare, you keep the same plan. In both cases you could end up paying more without realizing it.
I'm turning 65 soon, when do I enroll in Medicare?
Your initial period covers the 3 months before your birthday, the birthday month, and the 3 months after. Enrolling early avoids delays in your start date.
Can you remind me of my dates?
Yes. Message us on WhatsApp and we'll let you know when your window opens to review your plan together.