Final answer:
The Truth in Lending Act (TILA) requires healthcare providers to specify charges in writing and identify the interest as an annual rate.
Step-by-step explanation:
The act that requires the healthcare provider to specify charges in writing and to identify the interest to be charged as an annual rate is the Truth in Lending Act (TILA). TILA is a federal law designed to protect consumers in credit transactions by requiring lenders to provide certain key information about loans, including the cost of credit and the annual percentage rate (APR). In the context of healthcare, TILA applies to healthcare providers who offer financing options to patients.