Is there a best time to enroll in a Medicare supplement plan?

  • By
  • medicareresources.org Contributor
  • February 28, 2018

Q: Is there a best time to enroll in a Medicare supplement plan?

A: Yes. The best time to enroll is during your Medigap open enrollment period, a six-month window of time that begins on the first day of the month that you are aged 65 and are enrolled in Medicare Parts A and B.

During this period, a private insurance company that offers Medigap coverage can not:

  • refuse to sell you any Medigap policy it offers
  • make you wait for your coverage to take effect (except under certain circumstances); or
  • charge you additional fees for your coverage because of your medical history.

Even if you enroll during your initial enrollment period, a private Medigap insurer may refuse (for up to six months) to pay your out-of-pocket expenses if you have a pre-existing health issue. If your pre-existing condition was diagnosed or treated within six months prior to the date your Medigap supplemental coverage was to begin, the insurance company can make you wait six months before covering your out-of-pocket expenses.

But if you had creditable coverage before enrolling in Medigap, without a gap in coverage of more than 63 days, the pre-existing condition waiting period will be reduced by the number of months that you had creditable coverage. So if you had continuous coverage for six or more months before enrolling in Medigap, you won’t have a pre-existing condition waiting period. The rules can be confusing, so don’t hesitate to talk to a representative of the Medigap private insurance company for clarification.

Buying a Medigap plan after your enrollment initial window closes

After your six-month open enrollment window, Medigap plans are medically underwritten in nearly every state, meaning that if you apply for coverage outside of your open enrollment window, you can be declined or charged more based on your medical history (New York and Connecticut are the exceptions; Medigap plans in those states are available year-round, without medical underwriting).

There are also some limited special enrollment periods for Medigap coverage, including

  • Moving out of your plan’s service area
  • Losing a group or retiree plan that has been paying secondary to Medicare
  • The Medigap or Medicare Advantage plan you’re on leaves Medicare or stops offering coverage in your area, or you leave the plan because they didn’t follow Medicare’s rules.
  • You enrolled in a Medicare Advantage plan when you first became eligible for Medicare, and are utilizing your “trial right” to switch to Original Medicare within 12 months of purchasing the Medicare Advantage plan (this only applies the first time you join Medicare Advantage).
  • You were previously enrolled in Original Medicare plus a Medigap plan, and dropped them in order to enroll in Medicare Advantage, and decided within 12 months that you wanted to switch back. You’ll be limited to switching back to your original Medigap plan, unless it’s no longer available. In that case, you’ll be able to pick a different Medigap plan. But although people can switch back and forth between Original Medicare and Medicare Advantage every year, the option to have guaranteed-issue access to Medigap in this scenario is limited — it only applies the first time you’re switching back to your old Medigap plan, and only if you do so within 12 months of leaving the Medigap plan.

Louise Norris is an individual health insurance broker who has been writing about health insurance and health reform since 2006. She has written dozens of opinions and educational pieces about the Affordable Care Act for healthinsurance.org. Her state health exchange updates are regularly cited by media who cover health reform and by other health insurance experts.