How many days does Medicare cover the full cost in a skilled nursing facility under Part A?

Medicare Part A provides coverage for skilled nursing facility care, but this is only after certain conditions are met, such as a qualifying hospital stay of at least three days. Once admitted to a skilled nursing facility, Medicare covers the full cost for the first 20 days of care. This coverage includes necessary medical services and treatments provided in a skilled nursing facility, helping to ensure that beneficiaries receive proper rehabilitation and supportive care after a hospital stay.

After the initial 20-day period, if further skilled nursing care is required, Medicare may cover an additional days up to a maximum of 100 days, but starting from day 21, costs increase significantly. So, in the context of Medicare's coverage, the focus is on the first 20 days being fully covered, making this the correct answer. The options representing days beyond this duration do not reflect the correct period for full Medicare coverage in a skilled nursing facility.