An insurance plan that is designed to protect you from paying high out-of-pocket costs. It is geared towards patients who are generally healthy and don't need to visit their physician on a regular basis. This plan usually covers hospital stays, x-rays, and surgical expenses. Medicare Part A and Part B does not offer catastrophic coverage but Medicare Part D (prescription drug coverage) does offer it. After you have spent a certain out-of-pocket amount, you will only pay 5% of the cost for each prescription in addition to the monthly plan premium. Medicare private plans may also have catastrophic coverage but the caps may exclude certain high cost services.