ExpertGlossary

A pre-existing condition is a health problem that you already have when you apply for insurance.

If you have a pre-existing condition, an insurer can refuse to cover treatment connected to that problem for a period of time. That period is often the first six months, but may be for the entire term of your policy.

Insurers can also deny you coverage entirely because of a pre-existing condition. And they can end a policy if they discover a pre-existing condition that you did not report, provided you knew it existed when you applied for your policy.

However, if you're insured through your employer's plan and switch to a job that also provides health insurance, the new plan must cover you regardless of a pre-existing condition.