Skip to Main Content


The Outcome and ASsessment Information Set (OASIS) is a group of data elements that:

  • Represent core items of a comprehensive assessment for an adult home care patient; and
  • Form the basis for measuring patient outcomes for purposes of outcome-based quality improvement (OBQI).

The OASIS is a key component of Medicare's partnership with the home care industry to foster and monitor improved home health care outcomes and is proposed to be an integral part of the revised Conditions of Participation for Medicare-certified home health agencies (HHAs) – see the Regulations page on this site.

Most data items in the OASIS were derived in the context of a CMS-funded national research program (co-funded by the Robert Wood Johnson Foundation) to develop a system of outcome measures for home health care.  This program, and the OASIS, have evolved over 10-year developmental period.  The core data items were refined through several iterations of clinical and empirical research.  Other items were added later by a workgroup of home care experts to augment the outcome data set with selected items deemed essential for patient assessment.  The goal was not to produce a comprehensive assessment instrument, but to provide a set of data items necessary for measuring patient outcomes and essential for assessment – which HHAs in turn could augment as they judge necessary.  Overall, the OASIS items have utility for outcome monitoring, clinical assessment, care planning, and other internal agency-level applications.

Below you will find information on:

  • Main Components and General Application
  • Using OASIS Items in Assessment and Care Planning
  • Compliance Requirements
  • OASIS Assessment Reference Sheet