PDGM: The Complete Guide to the Patient-Driven Groupings Model

What is PDGM?

The Patient-Driven Groupings Model (PDGM) is the Medicare payment system for home health services, effective January 1, 2020. PDGM removed therapy visit thresholds from the payment calculation and instead bases reimbursement on patient clinical characteristics. Each 30-day period of care is classified across five case-mix variables that combine into a case-mix weight, which is multiplied by the base payment rate to determine the agency's payment.

In practice, PDGM shifted home health revenue away from visit volume and toward accurate diagnosis coding and OASIS documentation. Agencies with strong coding and OASIS accuracy operations capture the reimbursement their clinical work supports; those without leave revenue on the table.

The 5 case-mix variables that determine PDGM payment

Every 30-day period is classified along these five dimensions. The combination produces the case-mix weight for that period.

The 12 clinical groupings

The principal diagnosis reported on the claim assigns the period to one of twelve clinical groupings — for example Musculoskeletal Rehabilitation, Neuro/Stroke Rehabilitation, Wounds, Complex Nursing Interventions, MMTA (Medication Management, Teaching and Assessment) subgroups, Behavioral Health, and others. Groupings carry materially different payment weights, so selecting a principal diagnosis that does not reflect the documented clinical complexity can move a period into a lower-paying grouping.

This is why staying current on ICD-10 updates and specialist coding & OASIS review are the highest-leverage PDGM investments — the grouping decision happens at the coding step.

Functional impairment level

PDGM assigns each period a functional impairment level of low, medium, or high, derived from a set of OASIS items covering grooming, dressing (upper and lower body), bathing, toileting, transferring, and ambulation. Higher documented (and clinically supported) impairment increases the case-mix weight.

• Score to safe capability, not just physical ability — CMS guidance treats unsafe performance as dependency.
• Keep OASIS responses consistent with the visit narrative and the coded diagnoses.
• Re-verify start-of-care scoring; systematic under-scoring at SOC suppresses both revenue and outcome measures.

Comorbidity adjustment

Secondary diagnoses can add a comorbidity adjustment of none, low, or high. A low adjustment applies when a single qualifying comorbidity is present; a high adjustment applies when two or more comorbidities interact within CMS-defined subgroups. Systematically capturing documented chronic conditions — the same discipline that drives HCC risk-adjustment accuracy — is what unlocks the high comorbidity adjustment when it is warranted.

How to optimize revenue under PDGM

PDGM performance is a clinical-operations function, not just a billing one. The agencies that perform best share four habits:

• Specialist coding that selects the principal diagnosis supporting the correct clinical grouping.
• Systematic OASIS review to make functional scoring accurate and defensible.
• Complete secondary-diagnosis capture to earn the comorbidity adjustment.
• Pre-submission denial prevention so clean claims are paid on first pass.

Medeoan delivers these through end-to-end revenue cycle management, coding & OASIS review, and clinical documentation review — the operations that turn accurate documentation into the payment your clinical work supports.

PDGM frequently asked questions