Activities of Daily Living (ADL) Assessment

An ADL assessment measures a person's ability to perform basic self-care tasks — bathing, dressing, eating, toileting, transferring, and continence — to determine what help they need and how much. The instrument used depends on the setting: Medicare-certified home health uses the OASIS data set, while state Medicaid HCBS programs use their own functional assessment tools ^[1].

In Medicare-certified home health, ADLs are captured within the Outcome and Assessment Information Set (OASIS), a comprehensive assessment whose M1800-series items score functional status — grooming, dressing upper and lower body, bathing, toilet transferring, toileting hygiene, transferring, ambulation, and feeding. The current version, OASIS-E2, takes effect April 1, 2026. Since January 1, 2025, agencies must collect and submit OASIS on all patients regardless of payer, and all-payer data feeds the Home Health Quality Reporting Program beginning with the CY 2027 program year. OASIS is not collected for patients under 18, patients receiving only maternity services, or patients receiving only personal care, homemaker, or chore services. Medicaid HCBS and personal care programs do not use OASIS. Instead, each state selects a functional assessment tool used to establish level-of-care eligibility, build the person-centered service plan, and, in many states, set the individual's authorized service hours or budget. These instruments most commonly assess ADLs, IADLs, cognition, behavioral health, and general health status; the interRAI suite is the most widely adopted, though many states use homegrown tools built for their populations. CMS has also developed the Functional Assessment Standardized Items (FASI) to move toward standardized HCBS functional data across states. The classic clinical foundations — the Katz Index for ADLs and the Lawton scale for IADLs — underlie most of these tools.

ADL scores are not a clinical formality — they set the money. In Medicare home health, OASIS functional items feed the PDGM functional-impairment level that helps determine the payment for the period, so under-scoring a patient's dependency understates acuity and leaves revenue on the table, while over-scoring invites audit. In Medicaid HCBS, the state's assessment often directly caps the authorized hours in the plan of care, so an inaccurate assessment either short-changes the client's care or exposes the agency to overpayment findings. The all-payer OASIS requirement in effect since January 1, 2025 raises the stakes: assessment errors now propagate across every payer and, from the CY 2027 program year, into publicly reported quality data. Inter-rater reliability is the practical risk to manage — two clinicians scoring the same patient differently is where both revenue leakage and audit exposure originate.