occur during the 30-day period following an inpatient discharge of such an individual. (II) Expenditures that are with respect to return emergency room visits of an individual that occur during the 15-day period following an inpatient discharge of such an individual. (III) Such other expenditures as may be specified by the Secretary. (iii) Additional definitions (I) Applicable DRG For purposes of clause (i)(I), the term applicable DRG means a diagnosis-related group (including, as applicable, a sub-categorization of a diagnosis-related group) for which there is a reasonable expectation that the pattern of post-acute care expenditures is stable and predictable based on the reason for the initial discharge. (II) Post-acute care episode period (aa) In general For purposes of clause (i), the term post-acute care episode period means, with respect to an initial discharge of an individual and subject to item (bb), the period consisting of the 30-day period that begins with the date of such initial discharge. (bb) No overlap of periods For purposes of this subsection, an individual may not be considered, at any one time, to be within more than one post-acute care episode. (6) Selection of methods for identifying potentially-avoidable outcomes and method of risk adjustment (A) Methods for identifying potentially-avoidable outcomes The Secretary shall select a methodology for identifying potentially-avoidable complications and a methodology for identifying potentially-avoidable readmissions, and shall specify the circumstances under which such complications and such readmissions would be considered potentially avoidable. Each such methodology shall meet the following criteria: (i) The methodology shall provide— (I) in the case of potentially-avoidable complications, a comprehensive identification of all conditions that could reasonably be considered a complication of care that meets the requirements under paragraph (5)(A) to be included as a potentially-avoidable complication