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OASIS Data Sets

Background and Updates

Effective January 1, 2017, OASIS-C2 is the current version of the OASIS data set.  It was developed from OASIS-C1/ICD-10 to accommodate new data being collected for the Home Health Quality Reporting Program in support of the IMPACT Act. The OASIS-C2 data item set was approved by the Office of Management and Budget (OMB) on December 9, 2016 and will be implemented on January 1, 2017. The materials related to previous versions of the OASIS can be found in the Archives section of this site.

August 4, 2017

OASIS-C2 2018 Guidance Manual Available

The 2018 guidance manual for the OASIS-C2 version of the OASIS data set is available in the Downloads section below and on the OASIS User Manuals webpage. This version corrects errata from the previous version and contains clarifications about the One Clinician Rule. The effective date is January 1, 2018.

July 25, 2017

Supplemental HH QRP materials described in the CY 2018 HH PPS Notice of Proposed Rule Making (NPRM) have been posted. The following documents can be found in the “Downloads” section:

  • Testing of Standardized Function Assessment Items Summary CY18 HH PPS Rule
  • Proposed Data Elements to be Removed from OASIS on January 1, 2019

November 08, 2016

A corrected version of the OASIS C-2 Item Set, correcting 2 minor typos on page 3 of the all time points version, has been posted on the OASIS Item Set page. The document can be found in the Downloads section.


  • The OASIS-C2 is scheduled for implementation on January 1, 2017.
  •  The version includes three new standardized items (M1028, M1060, GG0170c), along with modification to and renumbering of select medication and integumentary items to standardize with other post-acute settings of care (M1311, M1313, M2001, M2003, and M2005).
  •  The lookback period and item number was changed in five items (M1500, M1510, M2015, M2300 and M2400).
  •  Formatting changes were made throughout the document to convert multiple check boxes to a single box for data entry, where responses are mutually-exclusive, and to change the numbering for pressure ulcer staging from Roman to Arabic numerals.
  •  The complete set of OASIS-C2 data items can be found in the Downloads section below.

OASIS and Medicare Home Health PPS

The most current information about Home Health PPS and use of OASIS can be found on the Home Health PPS web page via the link in the “Related Links” section below.