To amend title XVIII of the Social Security Act with respect to the work geographic index for physician payments under the Medicare program, and to revise the phase-in of clinical laboratory test payment changes under such program.

HR 6366 delays certain Medicare payment adjustments for physicians and clinical laboratories. It extends the effective year for the "work geographic index" (which sets physician payment rates by location) from 2024 to 2025. The bill also shifts the timeline for implementing reduced Medicare payments for clinical lab tests, moving the phase-in period from 2024-2026 to 2025-2027 and adjusting the reporting years for private payor rate data. These changes directly affect Medicare payments to physicians and clinical laboratories under the Social Security Act. The bill makes technical adjustments to existing payment rules without altering the overall structure of Medicare reimbursement.