In a comment letter to the Centers for Medicare & Medicaid Services (CMS), Arnold Ventures supports recent efforts to improve payment accuracy in the Medicare Physician Fee Schedule (MPFS). The MPFS determines how clinicians are paid for services provided to the 33 million Americans with traditional Medicare and influences how private insurers pay clinicians. The comments support CMS’ efforts to improve payment accuracy through updates to practice expense methodology and recommend further reforms to improve service valuation using empirical data. The letter also encourages broader structural reforms to strengthen accountable care, including improvements to MSSP benchmarking, and creation of a permanent hybrid primary care payment option within MSSP.