Stepping into a skilled nursing facility administrator role means learning a payment model that decides how much the facility gets paid for every Medicare resident. That model is PDPM, the Patient-Driven Payment Model, and it runs on clinical characteristics rather than therapy minutes. If you are new to SNF billing, PDPM is where a lot of the revenue is won or lost. So let’s break down how it works and what a new administrator needs to know.

What PDPM Replaced & Why

Before PDPM, SNF payment under Medicare Part A was driven mostly by how many therapy minutes a resident received. The more therapy, the higher the payment. That setup rewarded volume of therapy over the actual needs of the patient.

PDPM changed the basis of payment. Instead of paying for therapy minutes, it pays based on the resident’s clinical picture, their diagnoses, and their care needs. The idea is to pay for the patient in front of you, not the number of therapy sessions logged. For a new administrator, the takeaway is that accurate clinical information now drives the money.

The Components That Set the Payment

PDPM does not produce one number. It builds the daily payment from separate components, each scored on its own.

The Five Case-Mix Components

The daily rate combines physical therapy, occupational therapy, speech-language pathology, nursing, and non-therapy ancillary components. Each one is classified based on the resident’s characteristics, and each adds to the total. A resident with heavy nursing needs and light therapy classifies differently than one with the reverse, and the payment reflects that.

The Non-Case-Mix Piece

On top of the case-mix components sits a flat non-case-mix amount that covers costs like room and board, the same for every resident. This part does not change with the patient’s condition.

The Primary Diagnosis Drives Everything

Under PDPM, the resident’s primary diagnosis is the starting point, and getting it right matters more than almost anything else in SNF billing.

The primary diagnosis, coded in ICD-10, maps the resident into a clinical category that shapes the therapy components. Pick the wrong primary diagnosis or code it loosely, and the resident lands in the wrong category, which throws off the payment. This is where new administrators see revenue slip, because the coding sits with staff who may not know how much rides on it.

Capture the Whole Clinical Picture

PDPM rewards documenting everything about the resident that affects care. Comorbidities, conditions, and services all feed the components, especially the non-therapy ancillary piece, which is driven by the resident’s other conditions. Miss them in the documentation and the facility gets paid less than the care costs.

The MDS Is Where It All Comes Together

The Minimum Data Set, or MDS, is the assessment that feeds PDPM. The data on the MDS is what classifies the resident into each component.

Accuracy on the 5-Day Assessment

The 5-day MDS assessment sets the classification for the stay, so accuracy there carries through the whole episode. A rushed or thin assessment locks in a low classification that costs the facility across every day of the stay. Training the MDS staff and reviewing assessments before they lock is one of the highest-value things a facility can do.

The Payment Changes Over the Stay

One feature that surprises new administrators is that PDPM does not pay the same amount every day.

The therapy and non-therapy ancillary components adjust over the course of the stay. The physical and occupational therapy payment tapers down the longer the resident stays. The non-therapy ancillary payment starts higher in the first few days, when costs tend to be highest, then drops. This variable per diem schedule means the facility earns more early and less later, which affects how you think about the timing of a stay.

Where SNF Billing Goes Wrong Under PDPM

A few mistakes cost facilities the most.

Wrong or loose primary diagnosis. This is the big one, since the primary diagnosis sets the clinical category and the therapy components.

Missed comorbidities. Conditions not captured on the MDS mean a lower non-therapy ancillary score and less payment.

Late or inaccurate MDS. The assessment drives the payment, so errors and delays here hit every day of the stay.

Ignoring the interrupted stay rule. When a resident leaves and returns within a set window, PDPM treats it as one continued stay rather than a new one. Miss this and the billing is wrong.

What a New Administrator Should Focus On

The revenue under PDPM comes down to a few habits.

Get the coding right. Make sure the staff coding the primary diagnosis know how much it drives the payment, and build a review step.

Document the full picture. Capture every comorbidity and condition on the MDS, since they feed the components.

Watch the assessment schedule. The MDS deadlines and accuracy are where the payment is set, so treat them as a priority.

Know the stay rules. The variable per diem and the interrupted stay rule change the math, so build them into how the facility plans and bills.

The Last Word

PDPM pays a skilled nursing facility based on the resident’s clinical needs, built from five case-mix components plus a flat base. The primary diagnosis and the MDS drive the classification, the payment tapers over the stay, and the non-therapy ancillary piece rewards capturing the resident’s full condition. For a new administrator, the lesson is that SNF billing under PDPM is a clinical documentation game as much as a billing one. Get the diagnosis right, document the whole patient, keep the MDS accurate and on time, and the payment follows. Treat the coding as an afterthought, and the facility leaves money on the table every single day of every stay.