This proposed rule would update the prospective payment rates for inpatient rehabilitation facilities (IRFs) for federal fiscal year (FY) 2020. As required by the Social Security Act (the Act), this proposed rule includes the classification and weighting factors for the IRF prospective payment system’s (PPS) case-mix groups (CMGs) and a description of the methodologies and data used in computing the prospective payment rates for FY 2020. We are proposing to rebase and revise the IRF market basket to reflect a 2016 base year rather than the current 2012 base year. Additionally, we are proposing to replace the previously finalized unweighted motor score with a weighted motor score to assign patients to CMGs and remove one item from the score beginning with FY 2020 and to revise the CMGs and update the CMG relative weights and average length of stay values beginning with FY 2020, based on analysis of 2 years of data (FY 2017 and FY 2018). We are proposing to update the IRF wage index to use the concurrent FY inpatient prospective payment system (IPPS) wage index beginning with FY 2020. We are soliciting comments on stakeholder concerns regarding the appropriateness of the wage index used to adjust IRF payments. We are proposing to amend the regulations to clarify that the determination as to whether a physician qualifies as a rehabilitation physician (that is, a licensed physician with specialized training and experience in inpatient rehabilitation) is made by the IRF. For the IRF Quality Reporting Program (QRP), we are proposing to adopt two new measures, modify an existing measure, and adopt new standardized patient assessment data elements. We also propose to expand data collection to all patients, regardless of payer, as well as proposing updates related to the system used for the submission of data and related regulation text.