Final answer:
Medicare Part A pays some of the hospital charges but does not cover the full cost. Patients are responsible for deductible charges and copayments.
Step-by-step explanation:
Medicare Part A pays some of the hospital charges for individuals who are eligible for Social Security benefits. However, it does not cover the full cost. Patients are responsible for a deductible charge and copayments. In the given scenario, Dr. Coccidioides sent a bill to Medicare for the $135 owed by Mr. Robinson. Medicare Part A will pay a portion of this bill, but the exact amount depends on the deductible and copayment amounts.