Do I need both Part A and Part B to buy a Medicare supplement policy in Texas?

Yes. The Texas Department of Insurance says you must have both Medicare Part A and Part B to buy a Medicare supplement policy. Your six-month open enrollment period itself is tied to when you enroll in Part B.

When does a Medigap policy start after I apply?

Medicare says a Medigap policy generally begins the first of the month after you apply. You can ask for a different effective date. If you are replacing coverage, line up the dates so you are not left without a policy.

Can an agent sell me a Medigap policy while I'm still in a Medicare Advantage plan?

Only if you are switching back to Original Medicare. Medicare says it is illegal for someone to sell you a Medigap policy while you have a Medicare Advantage Plan otherwise. Your Medigap coverage can't start until your Medicare Advantage coverage ends.

How are Medigap premiums set, and where do I find current prices?

Companies price Medigap policies in one of three ways: community-rated, issue-age-rated, or attained-age-rated. Premiums change over time, so check current rates with Medicare.gov's Medigap policy search or the Texas Department of Insurance list of companies. An agent or a HICAP counselor can explain which pricing method a policy uses.

I'm on Medicare before 65 because of a disability. Does that time count toward a waiting period later?

It can. Medicare's guide says Part A and Part B count as creditable coverage. If you have had Medicare for more than 6 months before you turn 65, that may remove a pre-existing condition waiting period when you buy a policy during your open enrollment period at 65.

How do I check that a Medicare supplement agent is licensed in Texas?

The Texas Department of Insurance says to verify agent and company licenses through its Help Line at 800-252-3439. Every agent listed on MeetBrokers holds a state license that you can verify by National Producer Number.

Medigap Open Enrollment Period: How the 6-Month Window Works

The Medigap Open Enrollment Period is a one-time, 6-month window that starts the first month you have Medicare Part B and you're 65 or older. During those 6 months, an insurance company can't turn you down or charge you more because of your health, though some policies can make you wait up to 6 months before covering a pre-existing condition. This guide explains when your window starts, what it protects, the guaranteed issue rights you may have later, and the Texas rules that apply.

Key takeaways

Your Medigap Open Enrollment Period lasts 6 months, starts with Part B at 65 or older, and does not repeat.
During the window, companies can't refuse to sell you any Medigap policy they offer, can't use medical underwriting, and can't charge more for pre-existing conditions.
If you delay Part B because you or your spouse is still working with group coverage, your window starts later, when you sign up for Part B.
After the window, you may be denied a policy based on your health unless you have a guaranteed issue right, such as losing certain coverage.
The version of Texas HB 2516 that passed does not create an annual birthday window for switching Medigap plans. Ask TDI or HICAP whether any switching rights apply to you. Texas does have special rules for people under 65 with a disability, ESRD, or ALS.

When does the Medigap open enrollment period start and end?

Under federal law, your Medigap Open Enrollment Period starts the first month you have Medicare Part B and you're 65 or older. It lasts 6 months. If your Part B starts in March and you're already 65, your window runs March through August.

Medicare says this window can't be changed or repeated, and unlike the fall Medicare Open Enrollment Period, it doesn't come back every year. If you're under 65 and on Medicare because of a disability, see the section on Texas rules for people under 65, because TDI gives you a second window after you turn 65.

The Texas Department of Insurance (TDI) describes the same thing for Texas. The Medicare supplement open enrollment period is six months and begins when you enroll in Part B.

What does Medigap open enrollment protect you from?

During your Medigap Open Enrollment Period, Medicare says an insurance company:

Can't refuse to sell you any Medigap policy it offers
Can't use medical underwriting to accept or deny you
Can't charge you more because of pre-existing health problems

Outside this window, things change. You may pay more and have fewer policy choices. The company is also allowed to deny you a policy if you don't meet its medical underwriting rules.

Can a policy still make you wait for a pre-existing condition?

In some cases, yes. Even during open enrollment, a Medigap company can refuse to cover your out-of-pocket costs for a pre-existing condition for up to 6 months. This is the pre-existing condition waiting period. The company can only exclude conditions that were treated or diagnosed within the 6 months before the policy starts. That is called the look-back period.

You can avoid the wait if you've had at least 6 months of continuous prior creditable coverage. That coverage only counts if you had no break longer than 63 days.

During any waiting period, Original Medicare still covers the condition for Medicare-covered services. You pay the Medicare coinsurance or copayment yourself.

In Texas, TDI says a company may require a waiting period of up to six months during open enrollment, unless you qualify for Medicare because of end-stage renal disease (ESRD) or ALS.

Is it the same as the October 15 to December 7 open enrollment?

No. TDI says the annual Medicare open enrollment period, October 15 to December 7, doesn't apply to Medicare supplement plans. The table shows how the windows differ.

Window	When it happens	How often	What it means for Medigap
Medigap Open Enrollment Period	6 months starting the first month you have Part B and are 65 or older	Once	Companies must sell you any policy they offer, with no medical underwriting (a pre-existing condition waiting period of up to 6 months may still apply)
Medicare Open Enrollment Period	October 15 to December 7	Every year	Doesn't apply to Medicare supplement plans
Federal guaranteed issue rights	Set by situation, often up to 63 days after coverage ends	Only when a qualifying event happens	You can buy certain policies with no health-based denial or pricing
Texas guaranteed issue right	63 days from coverage ending or the notice date, whichever is later	Only when a qualifying event happens	Certain plans, with no pre-existing condition waiting periods

Our open enrollment dates guide lists other Medicare windows side by side.

What if you delay Part B because you're still working?

If you or your spouse is still working and you have employer or union group coverage, you may decide to wait to sign up for Part B. When that coverage ends, you can sign up for Part B without a late enrollment penalty. Your Medigap Open Enrollment Period starts then.

Here's an example. Linda turns 65 while she still has coverage through her job, so she waits on Part B. She retires at 67. If her Part B starts July 1, her Medigap window runs July through December. Her health at 67 doesn't stop her from buying any policy a company offers during those months.

The mistake to avoid

Signing up for Part B while you still have job-based coverage starts the clock anyway. Medicare says your window lasts 6 months from Part B even if you still have employer coverage. If you don't plan to buy Medigap yet, that early enrollment can use up your window.

Talk with your benefits office before you decide. Our guide to the Part B late enrollment penalty explains how delaying Part B works, and the turning 65 Medicare checklist walks through the months in order.

What are guaranteed issue rights after the window closes?

Guaranteed issue rights, also called Medigap protections, let you buy certain Medigap policies in limited situations outside open enrollment. When you have one, the company must sell you a policy, must cover all pre-existing conditions, and can't charge you more because of health problems.

Federal guaranteed issue situations

Medicare's guide lists these situations:

Your Medicare Advantage plan ends or changes. The plan leaves Medicare, stops giving care in your area, or makes a significant network change, or you move out of its service area. This applies only if you switch to Original Medicare. You can apply as early as 60 days before coverage ends and no later than 63 days after.
Employer coverage that pays after Medicare is ending. This includes retiree, COBRA, or union coverage. Apply no more than 63 days after the latest of the coverage end date, the date on the notice, or the date on a claim denial.
Your Medigap company goes bankrupt, or your coverage ends through no fault of your own. Apply no more than 63 days after coverage ends.
A company didn't follow the rules or misled you. This covers leaving a Medicare Advantage Plan or dropping Medigap for that reason. Apply no more than 63 days after coverage ends.

How the Texas guaranteed issue right works

In Texas, TDI says the guaranteed issue right lasts 63 days from the date coverage ends or the date of the notice that it will end, whichever is later. Companies can't impose pre-existing condition waiting periods. TDI adds that people who lose Medicaid because of a change in their finances also have a guaranteed issue right.

Which plans you can buy depends on your situation. TDI lists these for Texas:

First eligible on or after January 1, 2020, at 65 or older or with ESRD or ALS: Plans A, B, D, G (including high-deductible G), K, or L
First eligible before January 1, 2020, at 65 or older or with ESRD or ALS: Plans A, B, C, F (including high-deductible F), K, or L
Under 65 with a disability: Plan A

The federal guide lists a different set for most federal situations. Ask TDI or a counselor which list fits your case.

Keep proof that your coverage ended

Save letters, notices, emails, claim denials, and the postmarked envelope. You may need to include them with your Medigap application to prove your guaranteed issue right.

Can you try Medicare Advantage and come back to Medigap later?

Sometimes. Medicare calls these trial rights.

You joined at 65. If you joined a Medicare Advantage Plan or PACE when you were first eligible for Part A at 65, and you switch to Original Medicare within the first year, you can buy any Medigap policy sold in your state. Apply up to 60 days before or no more than 63 days after your coverage ends.
You dropped Medigap for Medicare Advantage for the first time. If you've been in the plan less than a year, you can get your old Medigap policy back if the same company still sells it.

Trial rights may last an extra 12 months in certain circumstances. Outside a trial period, Medicare warns that if you drop Medigap to join a Medicare Advantage Plan, in most cases you may not be able to get the same policy, or any Medigap policy, back. Our Medicare Advantage vs. Medigap guide compares the two paths, and how to switch Medicare Advantage plans covers those windows.

Can you switch Medigap plans, and did Texas HB 2516 add a birthday rule?

Switching during your window

TDI says Texans can use open enrollment rights more than once during the six-month period. For example, you can cancel a policy you bought and buy any other Medicare supplement policy.

When you switch during open enrollment, Medicare says you get a 30-day free look and pay both premiums for the month you have both policies. TDI also says you can return a policy within 30 days for a full refund.

Switching after your window

In most cases, you have no federal right to switch Medigap policies outside your 6-month window unless you have a guaranteed issue right. A company may use your health history to decide.

Does Texas HB 2516 create a birthday rule?

You may have heard of a "birthday rule." The enacted text of Texas HB 2516 has no annual birthday enrollment window. A 60-day birthday window appeared only in the bill as first introduced, and it was not in the version that passed. Ask TDI or HICAP whether any switching rights apply to you.

What are the Texas rules if you're under 65?

Federal law generally doesn't require companies to sell Medigap to people under 65. Medicare's guide lists Texas among the states that require at least one policy for people under 65. If you already have Part B, you still get a Medigap Open Enrollment Period when you turn 65.

Under 65 with a disability (not ESRD or ALS)

TDI says you get a six-month open enrollment period starting when you enroll in Part B, but it applies only to Plan A. You get another open enrollment period during the first six months after you turn 65.

Under 65 with ESRD or ALS

HB 2516, the Chris Larkin ALS Act, requires insurers to offer the same Medicare supplement coverage to under-65 enrollees with ESRD or ALS. The six-month enrollment period begins the first day of the first month of Part B enrollment. Insurers can't use underwriting, a waiting period, or a pre-existing condition exclusion. The law applies to plans issued or renewed on or after September 1, 2025.

TDI says these enrollees can buy any available plan during open enrollment. Companies charge the same rate as a 65-year-old for Plans A, B, and D, and up to twice the age-65 rate for other plans.

HB 2516 also gave Texans under 65 who were already in Part B because of ESRD or ALS as of June 20, 2025, a one-time chance to apply between December 1, 2025, and June 1, 2026, as TDI Bulletin B-0010-25 explains. That main window has passed. But if you asked for an application during that time and it wasn't available, the law gives you six months from the date it becomes available. Ask TDI or HICAP whether this applies to you.

Can you still buy Plan C or Plan F?

Only if you were eligible for Medicare before January 1, 2020. Plans C and F aren't available to people new to Medicare on or after that date. If you were eligible earlier but didn't enroll, you may still be able to buy them. People newly eligible can buy Plans D and G instead.

A step-by-step timeline for your Medigap window

Before Part B starts. Decide when to enroll in Part B. If you have job-based coverage, check with your benefits office first.
Mark your 6 months. Count from the first month you have Part B and are 65 or older.
Compare policies. Use Medicare.gov's Medigap policy search or the TDI company list for current rates. Companies price policies as community-rated, issue-age-rated, or attained-age-rated, and premiums change.
Check your prior coverage. Note whether you've had 6 months of creditable coverage with no gap over 63 days, so you know if a waiting period could apply.
Apply inside the window. A policy generally begins the first of the month after you apply, unless you ask for another date.
Review within 30 days. Use the free look period if the policy isn't right.

Common mistakes to avoid

Missing the window. It doesn't come back, and later a company may deny you based on health.
Enrolling in Part B early while working. That starts your 6 months even if you're not ready to buy.
Assuming the fall enrollment period covers Medigap. TDI says it doesn't.
Dropping Medigap for Medicare Advantage after your trial period. You may not get a policy back.
Canceling your old policy before the new one is in force. Keep your old policy during the new policy's 30-day free look. You'll pay both premiums for the month you have both.
Throwing away coverage notices. They can prove a guaranteed issue right.

Where can you get free help with Medigap in Texas?

HICAP. The Texas Health Information, Counseling and Advocacy Program is the state's free SHIP counseling program. Reach it through the Texas Medicare Help Line at 800-252-9240. Counselors explain Medigap benefits and comparisons and serve Medicare beneficiaries of any age.
TDI. Verify agent and company licenses through the TDI Help Line at 800-252-3439. See how to verify a Texas insurance agent license.
Medicare. Call 1-800-MEDICARE with questions about Part B and your enrollment dates.

For a wider look at state rules, read Medicare in Texas.

What to do next

A licensed agent can help you compare Medigap policies during your window or check whether you have a guaranteed issue right. Review how to choose a Medicare agent before you meet with one.

MeetBrokers is free to use. Every listed agent holds a state license that anyone can verify by National Producer Number. Profiles marked "unclaimed" come from public licensing records. Browse licensed Medicare agents in Texas or Medicare agents in other states.

When you're ready, you can request help from a licensed Medicare agent in Texas. Your request goes only to the agent you choose. MeetBrokers is not connected with or endorsed by the U.S. government or the federal Medicare program.