A medical condition that a person has before
becoming covered by a new health insurance plan. Insurers can refuse to cover
people for preexisting conditions. Often there is a waiting period before insurance
becomes effective, which may allow preexisting conditions to be discovered.
Typically this situation is bypassed in the case of a job change; preexisting
conditions are not an issue because the employer’s plan is obligated to cover
employees whether they have a preexisting condition or not.