A practice by insurers of giving a low rate on health insurance to a low-risk small group or individual, then raising the rates when the insured start filing claims.
A physical or mental condition which has been discovered before an individual applies for health insurance. Insurers often deny insurance to individuals with certain preexisting conditions, or invoke a waiting period, or reject a group unless such individuals are excluded. Health care reform efforts today insist that there be no exclusion of individuals for such conditions.