The "Reforming and Enhancing Sustainable Updates to Laboratory Testing Services Act of 2025," or RESULTS Act, seeks to ensure long-term stability for Medicare beneficiary access to clinical diagnostic laboratory tests. It proposes significant changes to how Medicare determines payment rates for these tests, primarily by improving the accuracy and feasibility of data collection from private payors. A central provision involves shifting the responsibility for collecting private payor data for certain tests to an independent entity. Specifically, for "widely available non-ADLT clinical diagnostic laboratory tests" (common tests that are not advanced), starting January 1, 2028, the Secretary of Health and Human Services must contract with a qualifying independent claims data entity . This entity, a national nonprofit, will provide applicable information from its qualifying comprehensive claims database , which must contain at least 50 billion claims from over 50 private payors and meet strict criteria for representativeness, data validation, and privacy. This aims to ensure a more robust and accurate reflection of market rates. The bill updates the definition of "applicable information" to focus on final payment rates , explicitly excluding denied, appealed, erroneous, or recouped payments, thereby enhancing data quality. It also modifies the calculation of the weighted median of private payor rates to incorporate this new data source. To prevent payment disruptions, the legislation establishes a default mechanism: if the Secretary cannot contract with an independent entity or if data is unavailable, payment for widely available non-ADLTs will be adjusted by the Consumer Price Index. For "non-widely available non-ADLT clinical diagnostic laboratory tests" lacking reported data, payment will be determined through "cross-walking" to comparable tests or a "gapfilling" process. The bill also mandates that the Secretary publicly explain payment rates, including supporting data, to improve transparency. Furthermore, it revises the annual payment reduction limits, extending the 10% cap until 2028 and setting a 5% cap for 2029 and subsequent years, aiming to provide more predictable payment adjustments.