 Medicare Parts A and B provide no similar OOP spending cap and the exposure of a Medicare Part A and/or B beneficiary to a financial catastrophe is unlimited (but also rare).Once the OOP maximum is reached for an individual under a Part C health plan, the plan pays 100% of medical services for the remainder of the calendar year.That protection has no lifetime maximum, another problem with Medicare Part A which has a lifetime limit on inpatient hospitalization coverage.