PDPM “Case Mix Creep” and the Future of Reimbursement

For years, PDPM has been viewed as a more clinically accurate reimbursement model for skilled nursing facilities (SNFs). But in the FY 2027 proposed rule, CMS is raising a more pointed question:

Is PDPM reflecting patient acuity, or documentation behavior?

This question sits at the center of what CMS is calling potential “case mix creep.”

What CMS Is Observing

Since PDPM’s implementation, CMS has tracked notable increases in certain diagnosis categories, including:

• Malnutrition

• Swallowing disorders

• Depression

At the same time, CMS notes that increases in case mix indices appear to outpace what would be expected based solely on changes in patient population health status.

In simple terms, CMS is questioning whether coding practices, not just patient complexity, are influencing payment levels.

Why Now?

CMS is not just observing trends, it is signaling intent to evaluate whether PDPM needs recalibration.

The concern is straightforward: If documentation practices shift faster than actual patient acuity, payment models may drift away from intended design. That creates pressure on system integrity.

Implications for SNFs

If CMS moves forward with adjustments, providers could see:

• Changes in PDPM case-mix weights

• Increased audit activity targeting high-acuity coding patterns

• Greater emphasis on documentation justification for clinical conditions

• Potential recalibration of payment assumptions across categories

This is not about compliance alone—it is about reimbursement stability.

Operational Reality Behind the Data

Most providers are not “overcoding” intentionally. Instead, this issue often reflects:

• Improved clinical recognition of conditions

• Better documentation training post-PDPM

• Increased awareness of PDPM-driven reimbursement impact

• Variability in coding interpretation across organizations

Regardless of cause, CMS is now signaling that consistency and validation matter more than ever.

Where This Is Heading

The inclusion of “case mix creep” in a formal request for information is significant. It means CMS is actively gathering input before potential policy adjustments.

That typically precedes:

• Model refinement

• Weight recalibration

• Increased validation processes

Strengthening Documentation for What’s Ahead

As CMS evaluates whether PDPM reflects true patient acuity, the pressure on documentation accuracy and coding consistency will continue to increase.

This is where interdisciplinary alignment and structured documentation practices become critical, not only for compliance, but for reimbursement stability.

Organizations that invest in these areas now will be best positioned as policy and payment models continue to evolve.

Jennifer Napier is the practice director at Engage Consulting, a consulting firm that partners with post-acute leaders to solve complex clinical and regulatory challenges. With more than 19 years of experience in long-term and post-acute care, her expertise includes MDS, reimbursement, quality, compliance, and audit-related strategy.