Hospital-Acquired Condition (HAC)

What is a Hospital-Acquired Condition?

A HAC is a condition that CMS has determined to be reasonably preventable through evidence-based care and that was not present on admission (POA). CMS refuses to pay the higher DRG rate that would apply if the condition were the reason for admission. The HAC Reduction Program, established by the ACA, penalizes the bottom-performing 25% of IPPS hospitals by HAC score with a 1% reduction applied to all Medicare DRG payments for that fiscal year. The composite HAC score has two domains: Domain 1 (AHRQ Patient Safety Indicator-90 composite, weighted 35%) and Domain 2 (CDC NHSN healthcare-associated infection measures — CLABSI, CAUTI, SSI, MRSA bacteremia, and C. difficile — weighted 65%). The POA indicator on each ICD-10 diagnosis code is critical: if a condition was POA, it is excluded from HAC calculations. Never Events (a subset of HACs) such as wrong-site surgery, retained surgical items, and air embolism receive $0 Medicare reimbursement for any resulting care.

Why It Matters for Healthcare Analytics

A 1% Medicare DRG payment reduction across an entire hospital can represent millions of dollars for large facilities. Tracking HAC score components — SIR (Standardized Infection Ratio) for each NHSN measure and PSI-90 composite performance — against national and peer benchmarks is essential for avoiding the penalty. Equally critical is POA documentation accuracy: a condition incorrectly coded as not POA artificially inflates your HAC event count.

How Vizier Tracks HACs

Upload your discharge and infection surveillance data, then ask "What is our HAC Reduction Program score trend by domain this year?" — Vizier calculates domain scores, compares them to the penalty threshold, and identifies which HAI measure is contributing most to your risk.