OASIS (Outcome and Assessment Information Set)
OASIS is the standardized comprehensive assessment tool required for all Medicare and Medicaid home health patients, used to classify patients for PDGM payment, calculate Home Health Compare quality measures, and track functional outcomes.
What is OASIS?
OASIS-E, the current version effective January 2023, is a standardized 100+ item assessment instrument that home health agencies must complete for all Medicare and Medicaid patients at defined assessment time points: start of care, resumption of care after an inpatient stay, recertification, discharge, and transfer to an inpatient facility. OASIS items are organized into M-items (clinical record items covering grooming, dressing, ambulation, and other ADLs such as M1800 Grooming and M1810 Dress Upper Body) and GG items (functional ability items covering mobility and self-care). The GG items are particularly important because they directly drive PDGM functional impairment level classification — low, medium, or high — which determines the HIPPS payment code for each 30-day payment period. Beyond payment, OASIS data is the sole source of information for Home Health Compare quality measures publicly reported by CMS, including improvement in ambulation, improvement in bathing, improvement in pain interference with activity, and the potentially avoidable hospitalization rate. Because OASIS is simultaneously the payment driver, quality measure source, and care planning foundation, coding accuracy is financial and clinical-critical — errors in GG items can shift a patient to a lower PDGM payment group with no mechanism for correction after the assessment window closes.
Why It Matters for Healthcare Analytics
OASIS coding errors have a direct and immediate financial consequence through PDGM misclassification, and a delayed but equally consequential quality impact through inaccurate Home Health Compare scores. Tracking HIPPS code distribution, identifying patients at risk of functional classification downgrades, and monitoring outcome improvement rates by clinician provides the analytical foundation for both revenue optimization and quality improvement.
How Vizier Tracks OASIS
Upload your OASIS assessment data, then ask "What is our HIPPS code distribution and which functional impairment levels are most common by clinical grouping?" — Vizier analyzes OASIS coding patterns, identifies GG item outliers that may indicate undercoding, and benchmarks your functional outcome improvement rates against national Home Health Compare data.