Episode-based cost measures represent the cost to Medicare for the items and services provided to a patient during an episode of care (“episode”). In all supplemental documentation, “cost” generally means the standardized1 Medicare allowed amount,2 and claims data from Medicare Parts A and B are used to construct the episode-based cost measures. The Renal or Ureteral Stone Surgical Treatment episode-based cost measure evaluates a clinician’s risk-adjusted cost to Medicare for beneficiaries who receive surgical treatment for renal or ureteral stones during the performance period. The cost measure score is the clinician’s risk-adjusted cost for the episode group averaged across all episodes attributed to the clinician. This procedural measure includes costs of services that are clinically related to the attributed clinician’s role in managing care during each episode from 90 days prior to the clinical event that opens, or “triggers,” the episode through 30 days after the trigger.