Medigap Open Enrollment: Avoid These Costly Mistakes When Signing Up

If you’re enrolling in Medicare, understanding the Medigap Open Enrollment Period is crucial for getting the best coverage without medical underwriting. This six-month window gives you guaranteed access to a Medicare supplemental plan (Medigap) without health questions or rate increases due to pre-existing conditions. Missing this period could mean higher costs—or worse, being denied coverage altogether. Here’s what you need to know to make the right decision.

1. What Is the Medigap Open Enrollment Period?

The Medigap Open Enrollment Period begins the first month your Medicare Part B coverage starts and lasts for six months.

Why This Matters

• During this window, insurance companies cannot deny you coverage or charge you higher premiums based on health conditions.
• After this period, you must medically qualify to enroll in a Medigap plan, which means answering health questions and risk being denied.

Once this window closes, your options become more limited—so timing is everything.

2. Benefits of Choosing a Medigap Policy

Medigap policies help cover out-of-pocket costs that Medicare doesn’t pay, such as deductibles and co-pays. Here’s why they’re a preferred option:

Low out-of-pocket costs – The only out-of-pocket cost with a Plan G Medigap policy is the $257 Part B deductible (2025).

No provider networks – Medigap works with any doctor nationwide who accepts Medicare, offering flexibility and portability.

No referrals needed – Unlike Medicare Advantage plans, you don’t need a primary care doctor’s approval to see a specialist.

No pre-authorizations – You and your doctor decide on treatments, not the insurance company.

Lifetime coverage – As long as you keep paying your premium, your policy won’t be canceled.

3. When Should You Enroll in Medicare Part B?

Your Medigap Open Enrollment Period depends on when you sign up for Medicare Part B. Here are the key enrollment periods:

Initial Enrollment Period (IEP)

• Begins three months before your 65th birthday and lasts until three months after.
• Your Part B coverage starts on the first day of your birth month (unless you delay enrollment).

Special Enrollment Period (SEP)

• For those covered by active employer health insurance, delaying Part B is penalty-free.
• Once employer coverage ends, you have 8 months to enroll in Part B and 6 months to enroll in Medigap without medical questions.

General Enrollment Period (GEP)

• Runs January 1 – March 31 each year.
• Coverage begins the following month, but late enrollment penalties may apply.

4. What Happens If You Miss the Medigap Open Enrollment Period?

After the six-month window, insurance companies can deny your application or charge higher premiums based on your health. Here’s what to expect:

Medical Underwriting – You must answer 30+ health questions and disclose current medications.

Risk of Denial – Carriers can reject your application based on pre-existing conditions.

Higher Premiums – If accepted, you may face higher monthly costs due to medical history.

If you don’t qualify for Medigap after missing your open enrollment period, your only alternative may be a Medicare Advantage (Part C) plan—which comes with network restrictions, pre-authorizations, and higher out-of-pocket costs.

5. How to Avoid Medigap Enrollment Mistakes

Don’t Delay Signing Up for Part B – Your Medigap Open Enrollment Period depends on when your Part B coverage begins.

Work With an Independent Medicare Broker – Some agents may push Medicare Advantage plans for higher commissions. A trusted, independent broker will explain all options.

Verify Medigap Plan Options – Compare Plan G, Plan N, and high-deductible options to find the best fit for your health needs and budget.

Plan Ahead – If you’re delaying Medicare due to employer coverage, mark your calendar to enroll in Medigap as soon as you retire.

Final Thoughts: Secure Your Medigap Coverage While You Can

Missing your Medigap Open Enrollment Period could cost you thousands in out-of-pocket expenses or even leave you without coverage. If you’re approaching Medicare eligibility or leaving employer coverage, act fast to lock in affordable, comprehensive Medigap benefits without medical underwriting.

Have questions about your Medigap options? Comment below! I’d love to hear about your experience and help you navigate your Medicare choices.