TX HB1641

Prohibits health maintenance organizations (HMOs) and insurers from using extrapolation—a mathematical technique that estimates audit results for a larger group of claims based on a sample—when auditing physicians or providers

Requires any payment adjustments (additional payments to providers or refunds to HMOs/insurers) to be based on actual overpayments or underpayments, not extrapolated estimates

Exempts government health benefit plans from the extrapolation prohibition, including the child health plan program (CHIP), children's health benefits plans, and Medicaid programs including managed care

Applies only to audits under physician or provider contracts entered into or renewed on or after September 1, 2025

Takes effect September 1, 2025