The Risk-standardized Complication Rate (RSCR) following Elective Primary Total Hip Arthroplasty (THA) and/or Total Knee Arthroplasty (TKA) for the Merit-based Incentive Payment System (MIPS) measure is a risk-standardized complication rate for Medicare Fee-for-Service (FFS) beneficiaries aged 65 or older who experienced complications after an inpatient elective primary THA and/or TKA procedure, defined as complications occurring from the date of index admission to 90 days post discharge. The measure attributes complications to MIPS participating clinicians and/or clinician groups, as identified by their National Provider Identifiers (NPIs) and Taxpayer Information Numbers (TINs) and assesses each clinician’s or clinician group’s complication rate.