One feature of most individual medical insurance policies is the exclusion of pre-existing conditions.

This term refers to any illness or physical condition that existed before the effective date of the policy and one that the applicant did not disclose when applying for the policy. An existing condition must be noted on the application to be excluded by a rider or a waiver. All medical costs incurred due to a preexisting condition will not be covered by the medical policy. The exclusion is only applicable for a limited time. After the time limit has passed, all pre-existing conditions will be covered in full, as they are not considered to be "pre-existing" any longer. Group health insurance plans recognize preexisting conditions as any condition for which a participant has received treatment during the three months prior to the effective date policy.