Which are used to calculate reimbursement for hospital-based Medicare outpatient claims?

The correct answer is APCs, which stands for Ambulatory Payment Classifications. APCs are a system used to categorize outpatient services provided by hospitals under the Medicare program. This classification system is specifically designed to determine reimbursement amounts for the various services rendered in an outpatient setting.

APCs group similar services together based on clinical and cost factors, which simplifies the billing process and provides a consistent payment structure for outpatient care. Each APC is assigned a fixed payment rate, allowing hospitals to receive predictable reimbursement based on the services they provide.

In contrast, the other options pertain to different aspects of healthcare reimbursement. DRGs (Diagnosis-Related Groups) are primarily used for inpatient services, categorizing stays into diagnoses to determine payment for hospitals. RBRVS (Resource-Based Relative Value Scale) is used for setting prices for physician services, while RUGs (Resource Utilization Groups) pertains to nursing home services under Medicare. These distinctions clarify why APCs are the proper choice related to outpatient claims specifically within the Medicare framework.