Уведомление о прекращении действия договора медицинского страхования.

"Он лучше выдумать не мог".

Let's say you get insurance through your job for 9 months, and then when you leave your job you immediately purchase an individual policy that has a preexisting condition exclusion period of 12 months. In this case, you can use your 9 months of prior creditable coverage to shorten your preexisting condition exclusion period to 3 months. If your prior creditable coverage had been longer than 12 months, you would not have had to wait through a preexisting condition exclusion period at all.

You will lose all of your creditable coverage if you have a lapse in coverage of 63 days or more - which is why it is to your advantage to stay continuously covered. In the example above, if you left your job but waited 4 months before buying your individual policy, you would have to wait through the entire 12 month preexisting condition exclusion period no matter how many months of creditable coverage you had.

Federal law states that almost all kinds of health insurance coverage are creditable, including group health coverage, individual policies, HMOs, Medicare, and Medicaid. Health plans that only cover specific medical conditions like cancer are not creditable.

Термин "гарантированное страховое покрытие" распространён, достаточно погуглить. Правда, не совсем уверен, что это именно то.

--------------------------------------------------
Note added at 4 час (2009-08-22 18:57:22 GMT)
--------------------------------------------------

Не сертификат уведомляет, а, вероятно, в сертификате указывается (делается отметка, например) о прекращении гарантированного страхового покрытия. Сertificate of creditable coverage - не термин, а эвфемизм.

Certification of Creditable Coverage is a statement showing your dates of coverage. This statement acts as a "receipt" and is automatically given to any covered person by an insurer