Medicare involves several enrollment periods, two main ways to receive coverage, and important differences between federal rules and Texas insurance protections. A mistake can be costly—or can limit your options later. These ten issues are worth checking before a decision. This is a general educational checklist, not a substitute for guidance specific to your situation.
1. Assuming everyone should enroll in Part B immediately at 65
Part B enrollment timing depends on your circumstances, including whether you or your spouse are still working and whether coverage is based on that current employment. Employer size and other factors matter. Some people qualify for a Special Enrollment Period; others face gaps or penalties if they delay. Start with When Should You Start Medicare? and check Medicare.gov’s enrollment guide.
2. Confusing Medicare Annual Open Enrollment with Medigap Open Enrollment
The October 15–December 7 period generally lets people change Medicare Advantage and Part D coverage for the following year. It does not ordinarily guarantee the right to buy a new Medigap policy. The federal Medigap Open Enrollment Period generally lasts one time for six months beginning at age 65 or older with Part B. Learn about 2027 Open Enrollment.
3. Expecting a Texas Medigap birthday rule
Texas has no general annual birthday-rule window automatically allowing every Medigap member to change insurers without underwriting. Some other states do. Check the Texas-specific explanation: Does Texas Have a Medigap Birthday Rule?
4. Canceling a Medigap policy before replacement coverage is secure
Outside certain protected circumstances, a new company may evaluate your health and decline an application. Get the replacement policy approved, verify effective dates and understand the free-look period before ending current coverage. See what to do after a Medigap rate increase.
5. Assuming you can always return to Medigap after Medicare Advantage
Leaving Medicare Advantage for Original Medicare does not automatically guarantee eligibility to buy a Medigap policy. Certain trial and guaranteed-issue rights may apply, but they are specific and time-limited. This is an important factor when comparing coverage paths. Compare both approaches.
6. Treating a $0 Medicare Advantage premium as zero cost
A plan with a $0 additional monthly premium may still involve the Part B premium, copays, deductibles, drug costs and significant out-of-pocket exposure. Read the $0 Medicare Advantage explanation.
7. Checking an insurer’s network but not the exact plan
Medicare Advantage participation can differ among plans offered by the same company and can change from year to year. Confirm your doctor, hospital and pharmacy for the specific plan and coverage year. For a broader comparison use Medicare Plan Compare.
8. Forgetting to compare prescription drug coverage each year
Formularies, covered drug tiers, pharmacy arrangements and prescription costs can change. Compare your medications against the plans actually offered in your county for the year in question; consider how the Part D benefit applies to you.
9. Ignoring long-term Medigap premium affordability
Medigap benefits are generally standardized by plan letter, but insurers can charge different premiums and increase them over time. A low starting rate is only one part of the decision. Compare plan design, pricing method, discounts, company information and your ability to keep coverage. See Texas Department of Insurance: Medicare supplement guide.
10. Trusting an official-looking postcard or unverified agent
A mailer that looks governmental does not necessarily come from Medicare or Texas. Verify insurance professionals with the Texas Department of Insurance, and never give your Medicare number or financial details to an unexpected caller. Find official assistance on our resources page and use TDI’s license and company verification tools.
A practical starting order
If you are new to Medicare, begin with the Parts of Medicare, then enrollment timing, then coverage options. If you already own a Medigap policy, start with the switching and premium-increase guides.
Primary references: Medicare.gov; Texas Department of Insurance: Medicare supplement guide; Medicare.gov: Medigap enrollment and shopping; Texas Department of Insurance.
Official sources and editorial information
This guide is general education, not a personal recommendation or a promise of eligibility. Insurance protections vary by situation. Confirm the rules that apply to you directly with Medicare or the Texas Department of Insurance.
Research sources checked November 10, 2026. Publisher: Casey Pattison, Texas Insurance License #1215622; NPN #7619490. To report an error, email contact@txpolicy.com. Please do not send private health or insurance information.
