Medicare 2026

Medicare in Houston: The Two Paths and the Dates That Lock Them In

HOUSTON — Every fall, Houston retirees face the same fork in the road: stay with Original Medicare and pair it with a Medigap policy, or move to a Medicare Advantage plan. The two paths are built differently, and — this is the part people miss — the calendar treats them differently too. Miss the right window, and the door to one path can quietly close.

With the Annual Enrollment Period running Oct. 15 through Dec. 7, here is how the deadlines actually work, and what happens if you let one slip by.

The two paths, in one minute

Original Medicare is the federal program — Part A (hospital) and Part B (doctor/outpatient). It has no yearly out-of-pocket cap on its own. Most people add a Medigap policy to cover coinsurance and deductibles, and a stand-alone Part D plan for drugs.

Medicare Advantage (Part C) is a private plan that replaces how you get your Part A and B benefits. It usually includes drug coverage and has a yearly out-of-pocket maximum, but you generally use a network of doctors and hospitals.

Houston is in Harris County, where dozens of Medicare Advantage plans and multiple stand-alone Part D plans are offered each year. Availability is set at the county level, so your ZIP code — not just your city — determines your choices.

The deadline that decides your Medigap future

Here's the timing rule most people learn too late: your Medigap Open Enrollment Period is a one-time, 6-month window that begins the month you're 65 and enrolled in Part B. During that window, insurers in Texas must sell you any Medigap policy they offer, at their standard rate, regardless of your health.

After that window closes, Medigap insurers in Texas can use medical underwriting. That means if you pick Medicare Advantage first and later want to switch to Original Medicare + Medigap, the Medigap carrier can ask health questions — and can charge you more or turn you down.

There are limited "guaranteed issue" situations (for example, if your Advantage plan leaves the area, or a narrow trial-right window in your first year on Advantage), but they're the exception, not the rule.

The Annual Enrollment Period: Oct. 15 – Dec. 7

This is the big one. During AEP you can:

• Join, switch, or drop a Medicare Advantage plan.
• Join, switch, or drop a stand-alone Part D drug plan.
• Move from Medicare Advantage back to Original Medicare (and add a Part D plan).

Changes you make during AEP take effect Jan. 1. Note that AEP does not give you a guaranteed right to buy Medigap — that's a separate rulebook.

The Medicare Advantage Open Enrollment Period: Jan. 1 – March 31

If you're already in a Medicare Advantage plan on Jan. 1, you get one more chance in the new year to:

• Switch to a different Medicare Advantage plan, or
• Drop Advantage and return to Original Medicare (with a Part D plan).

You only get one change during this window, and again, it does not force Medigap insurers to sell you a policy without underwriting.

Part D deadlines still matter — even on the Medigap path

If you go Original Medicare + Medigap, you'll almost always want a stand-alone Part D plan. Signing up late — without other "creditable" drug coverage — can trigger a lifetime Part D late enrollment penalty added to your monthly premium.

A few program facts worth knowing as you compare:

• Part D out-of-pocket cap: $2,100 for the year.
• Part D maximum deductible: $615.
• The old coverage gap ("donut hole") is gone as of 2025; Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread your drug costs across the year in monthly installments if you choose.
• IRMAA income-based surcharges on Part B and Part D start above $109,000 for a single filer in 2026.

How the dates interact — three quick scenarios

• Turning 65 in Houston. Your Initial Enrollment Period and your 6-month Medigap Open Enrollment window are your cleanest shot at either path. Decide before that Medigap window closes.
• Already on Medicare Advantage and thinking about switching. AEP (Oct. 15 – Dec. 7) or the MA Open Enrollment Period (Jan. 1 – March 31) let you change plans or return to Original Medicare — but adding Medigap afterward may require passing health questions in Texas.
• On Original Medicare with Medigap and curious about Advantage. You can move during AEP. Just understand that coming back to the same Medigap plan later isn't guaranteed.