Case Mix Index (CMI)
Case mix index (CMI) is a numeric measure of the average clinical complexity and resource intensity of a facility's patients, derived from diagnosis-related group weights. A higher CMI signals more complex, higher-reimbursing cases and is used in payment, benchmarking, and capacity planning.
What is the case mix index (CMI)?
Case mix index (CMI) is a numeric measure of the average clinical complexity and resource intensity of the patients a facility treats, calculated from the relative weights assigned to diagnosis-related groups. A CMI above the baseline indicates a patient population that is, on average, more complex and resource-intensive than typical.
Because it summarizes complexity in a single figure, CMI offers a quick way to compare the acuity of one facility's caseload against another's or against benchmarks. The measure rises as a facility treats more complicated, higher-weighted cases.
Why does the case mix index matter in the revenue cycle?
A higher case mix index generally signals more complex cases that command higher reimbursement, so CMI is closely tied to expected revenue and is watched in payment and benchmarking. It also helps reveal whether documentation and coding are fully capturing the complexity actually treated.
Beyond payment, CMI informs capacity and resource planning, since a more complex caseload demands more staff time, supplies, and equipment per patient. Tracking CMI helps revenue-cycle and operations teams align reimbursement, coding accuracy, and resource allocation.
- what is case mix index
- cmi meaning
- case mix index definition
- what does cmi stand for
- how is case mix index calculated
- case mix index in healthcare