OASIS-E1

OASIS-E1 was deliberately small in scope. The headline addition was O0350, which asked whether the patient's COVID-19 vaccinations were up to date, mirroring an item already collected in other post-acute care settings. CMS also removed legacy items that had lost their purpose after the 2020 move to PDGM, since the model no longer paid based on episode timing responses or projected therapy visit counts collected on the assessment. Item intents, skip patterns, and guidance manual conventions otherwise carried forward from OASIS-E largely intact, which kept retraining needs modest.

CMS uses periodic OASIS revisions to keep the instrument aligned with the Home Health Quality Reporting Program and with standardized items collected across post-acute care settings under the IMPACT Act. OASIS-E, effective in 2023, was the major overhaul that introduced cross-setting sections like GG, C (cognition), and D (mood). OASIS-E1 was a cleanup release: add a required public health item, drop dead weight, and synchronize with the data specifications used in iQIES. Agencies should expect this cadence to continue, with small version bumps between larger redesigns.

OASIS-E2 took effect April 1, 2026 and is the current version. Relative to E1, it replaced M0069 (Gender) with A0810 (Sex), replaced the A1250 transportation item with A1255, and removed O0350, the COVID-19 vaccination item E1 had introduced. The applicable version is determined by the assessment date, so assessments completed before April 1, 2026 remain valid E1 records. Agencies do not go back and convert them.

E1-era assessments remain part of your quality history and audit trail:

• Keep E1 records retrievable in their original form for surveys, ADRs, and audits
• Expect quality measures to bridge versions; CMS maps comparable items across releases
• When trending internal dashboards across April 2026, annotate the version change
• Retire E1-specific training materials so new hires learn only current-version conventions