Healthcare Insights
Hospitals with the highest case mix index
A hospital’s case mix index (CMI) reflects the complexity of its patient population and the associated resources needed for their care.
What does a high CMI mean?
Many factors influence hospital case mix index such as a patient’s condition or overall health prior to their hospital stay, their diagnoses, and any procedures they may need during the course of their care.
Patients are classified into Medicare severity diagnosis-related groups (MS-DRGs) depending on case complexity and medical needs. The Definitive Healthcare HospitalView product uses the average of MS-DRG weights across inpatient claims to calculate a CMI.
Higher CMIs often result in higher reimbursement rates for hospitals. The Centers for Medicare and Medicaid Services (CMS) uses their own CMI calculations based on MS-DRGs and DRGs to determine reimbursement for Medicare and Medicaid beneficiaries.
For example, many of the top 20 hospitals on the list below specialize in spinal surgery, general or orthopedic surgery, or the heart, which can involve complicated patient procedures. Because they treat the most complex cases with potentially higher risk, the hospital may be reimbursed at a higher rate.
What is the national average case mix index for hospitals?
Definitive Healthcare calculates a case mix index value for more than 5,800 U.S. hospitals in our HospitalView product. The average CMI is 1.84, with a range of values from 0.56 to 5.89.
The following table lists the 20 highest case mix index hospitals. Results in this analysis are sourced from the Medicare Cost Report (MCR) and reflect the most recent 12-month interval tracked in our database. Only hospitals with more than 15 beds are included in the analysis.
| Rank | Definitive ID | Hospital name | City | State | Case mix index | Explore dataset |
|---|---|---|---|---|---|---|
| 1 | 4010 | Surgery Specialty Hospitals of America | Pasadena | TX | 5.89 | Explore |
| 2 | 1070377 | ARH Advanced Care - Kentucky River | Hazard | KY | 5.10 | Explore |
| 3 | 552489 | Nebraska Spine Hospital | Omaha | NE | 4.91 | Explore |
| 4 | 274123 | OrthoColorado Hospital | Denver | CO | 4.51 | Explore |
| 5 | 3332 | HPI Northwest Surgical Hospital | Oklahoma City | OK | 4.29 | Explore |
| 6 | 3321 | Oklahoma Spine Hospital | Oklahoma City | OK | 4.06 | Explore |
| 7 | 1756 | The Spine Hospital of Louisiana at the NeuroMedical Center (FKA the Neuromedical Center Surgical Hospital) | Baton Rouge | LA | 3.99 | Explore |
| 8 | 3744 | Ascension Saint Thomas Hospital for Specialty Surgery (FKA the Hospital for Spinal Surgery) | Nashville | TN | 3.86 | Explore |
| 9 | 1100 | Northwest Specialty Hospital | Post Falls | ID | 3.86 | Explore |
| 10 | 6419 | Akron Childrens Hospital | Akron | OH | 3.82 | Explore |
| 11 | 3901 | Baylor Scott & White the Heart Hospital Baylor - Plano | Plano | TX | 3.80 | Explore |
| 12 | 764511 | Baylor Scott & White the Heart Hospital - Denton | Denton | TX | 3.78 | Explore |
| 13 | 1317 | St Vincent Heart Center of Indiana | Carmel | IN | 3.75 | Explore |
| 14 | 553371 | Methodist Hospital for Surgery | Addison | TX | 3.69 | Explore |
| 15 | 4164 | Northwest Hills Surgical Hospital (AKA Austin Surgery Center) | Austin | TX | 3.68 | Explore |
| 16 | 329 | Fresno Surgical Hospital | Fresno | CA | 3.66 | Explore |
| 17 | 3364 | Tulsa Spine & Specialty Hospital | Tulsa | OK | 3.64 | Explore |
| 18 | 1018238 | Legent Orthopedic Hospital Carrollton | Carrollton | TX | 3.62 | Explore |
| 19 | 955051 | West Chase Houston Hospital (FKA Altus Houston Hospital) | Houston | TX | 3.58 | Explore |
| 20 | 1287 | Parkview Ortho Hospital | Fort Wayne | IN | 3.57 | Explore |
Fig. 1 Data is from the Definitive Healthcare HospitalView product and sourced from the Medicare Cost Report. Accessed October 2025.
Which hospitals have the highest case mix index?
Surgery Specialty Hospitals of America in Pasadena, Texas, and ARH Advanced Care in Hazard, Kentucky, have CMIs of 5.89 and 5.10 respectively, the highest among U.S. hospitals. Both hospitals specialize in complex procedures.
CMI for the top 20 hospitals on the list above ranges from 3.10 to 5.89, with an average CMI of 3.60.
How do CMI and acuity relate to one another?
Patient acuity is a measure of the severity of a patient’s illness or medical condition. It is used to triage patients and prioritize treatments. While CMI measures the average complexity of a facility’s entire patient population, acuity refers to the condition of a single patient.
As a measure of patients’ resource needs, CMI is directly correlated with acuity: A hospital that serves higher acuity patients will have a higher CMI than hospitals serving lower acuity patients.
How can CMI be used for identifying healthcare sales and marketing prospects?
Healthcare sales and marketing teams can use CMI to identify prospective customers for engagement. Organizations selling medical equipment, supplies, or technology designed to support complex or emergent care, for instance, may find success targeting facilities with higher CMIs.
Alternatively, particularly low CMIs at facilities designed to serve trauma patients or other typically complex populations may indicate the under-documentation of patient needs. Technology and consulting organizations focused on claims capture and medical documentation may target facilities with low CMIs and frame their offerings as opportunities to improve billing accuracy and reimbursement rates.
Learn more
CMIs are one of just hundreds of data points our clients leverage for their sales and marketing efforts. Read about some of the medtech use cases we support.
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