One of the biggest successes of the Affordable Care Act was the removal of pre-existing exclusions. No longer could insurance companies deny or charge more if you had pre-existing conditions. Since 25% of Americans have some form of chronic illness, this was a game-changer.
Many people believe that this applies to all types of health insurance. It may surprise many seniors (most of which have one or more pre-existing conditions) that this is not always the case. If you are turning 65 soon or just turned 65, please read this carefully:
What this means is that if you sign up for a Medi-Gap policy within 6 months of your 65th birthday, pre-existing conditions do not apply. But if you sign up for a Medi-Gap policy after that "open enrollment period", then the insurer can base your eligibility and costs on pre-existing conditions.
It is up to each insurer to decide. So if you miss the deadline, you should check on the policy benefits carefully when you choose such a plan.
(Note: this does not apply to original Medicare or Medicare Advantage plans which do not discriminate against pre-existing conditions.)