Optional State Assessment (OSA)

Effective October 1, 2023 when the revised MDS version 1.18.11 is implemented, Pennsylvania will begin using the Optional State Assessment (OSA) for payment purposes. The payment connection is for the determination of the Resource Utilization Groups (RUGs) which will continue to be used for the calculation of the Medicaid Case Mix Index (CMI) for Medicaid reimbursement. CMS will no longer support the RUG classifications after September 30, 2023 but Pennsylvania has not obtained legislative approval to switch from RUGs to PDPM for Medicaid CMI calculation.


The OSA will be completed as a stand alone assessment in correlation with all PPS and OBRA assessments except discharge assessments. It will be submitted with these assessments and must have the same assessment reference date (ARD) as the assessment it is being completed with. The OSA manual can be found on the CMS MDS webpage and in the attachment.


Minimum Data Set (MDS) 3.0 Resident Assessment Instrument (RAI) Manual | CMS