When considering group health insurance schemes there is generally confusion because, while some people say that group health insurance plans are not allowed to refuse you cover on the basis of your present health or your previous medical history, others argue that they are allowed to refuse cover in the case of pre-existing medical conditions.

The reality is that you may not be refused membership of a group health insurance plan solely as a result of you present health, including any disability that you might have, or as a result of your previous medical history.

Nonetheless, both employers and insurance companies are allowed to ask you if you have any pre-existing medical conditions when you join a plan or, if you submit a claim during your first year of coverage, to look back to see if you have a prior history of the condition which gives rise to the claim.

If a pre-existing condition is reported or discovered the employer or insurance company may not simply refuse you coverage under a group plan but may require an exclusion period for coverage of that particular pre-existing condition. This said, there are both federal and state laws that limit the exclusions that employers and insurance companies are permitted to place on their group health schemes.

Group health insurance schemes may not apply pre-existing condition exclusions as a result of genetic information or for pregnancy. Furthermore, exclusions are not permitted in the case of newborns, newly adopted children or children placed for adoption.

In general terms, pre-existing condition exclusions are only permitted for conditions that are diagnosed within the 6 months before joining a group health scheme for which you have been given (or been recommended to receive) treatment. This 6 month period is normally referred to as the 'look back' period.

When a pre-existing condition exclusion period is imposed it may not generally exceed 12 months and you have to receive credit for any previous continuous creditable coverage. In this case cover is considered to be continuous if it is not interrupted by a break of more than 63 days in a row. Almost all private and government sponsored health coverage is considered to be creditable and this will include such things as Medicare, Medicaid, Indian health insurance, student health insurance, individual health insurance, VA coverage, military health coverage, foreign national coverage and more.

If an employer imposes a waiting period for individuals to enter a plan, or an HMO imposes a similar affiliation period, these may not be counted in determining a break in continuous coverage. Further, pre-existing condition exclusion periods must take account of the waiting or affiliation period with the exclusion period starting on the same day as the waiting or affiliation period.

When moving between group schemes then your new plan administrator may examine your previous plan to calculate any credit towards a pre-existing condition exclusion period for your new plan. This may mean for example that if your new plan offers cover that was not provided under your previous plan then exclusion periods may be imposed for pre-existing conditions that were not covered before but that are covered under your new plan.

One final point to note is that you must be given appropriate notice of any exclusion period in writing and the group plan administrator must help you to obtain a certificate of creditable coverage from your former plan if you want him to do so.