Hospital Case Mix Data Specification Manuals

The Hospital Case Mix Data Specification Manuals provide information on the data file format, data specifications, data element definitions, and quality standards that data submitters must follow when submitting Case Mix files to CHIA.

• The FY2026 Redline Hospital Outpatient Observation Data Specifications are linked below. There are no changes to the HIDD and EDD specification manuals for 2026. CHIA hosted a webinar on to review the proposed changes. See the webinar presentation for more information. 
   - FY2026 Case Mix Updates Webinar (PDF) | PPT
  
  
• Both the FINAL FY2025 versions and the Redline FY2025 versions of the Hospital Case Mix Data Specifications for Hospital Inpatient Discharge Data (HIDD), Hospital Emergency Department, and Hospital Outpatient Observation are available below. CHIA hosted a webinar on May 16, 2024 to review the proposed changes. See the FY 2025 Case Mix Updates Webinar presentation (PDF) | PPT

• Other documentation including Transfer Organization ID listings, and Payer Sources Codes are also available for reference.

New!  FY2026 Hospital Redline Case Mix Data Specifications
(OOD Only)

(published Wednesday, April 9, 2025)

• Redline Hospital Outpatient Observation Data Specifications (PDF) | Word

FY2025 Hospital FINAL Case Mix Data Specifications

(published Wednesday, June 12, 2024)

• FINAL Hospital Inpatient Discharge Data Specifications (PDF) | Word

• FINAL Hospital Emergency Department Data Specifications (PDF) | Word

• FINAL Hospital Outpatient Observation Data Specifications (PDF) | Word

FY2025 Hospital Redline Case Mix Data Specifications

(published Monday, April 29, 2024)

• Redline Hospital Inpatient Discharge Data Specifications (PDF) | Word

• Redline Hospital Emergency Department Data Specifications (PDF) | Word

• Redline Hospital Outpatient Observation Data Specifications (PDF) | Word

Associated Case Mix Documentation for the Hospital Case Mix Data Specifications

• Transfer Organization ID (ORG ID) List (Excel)
  (Updated January 2025)
  
  
  
• CDC Ethnicity Codes (PDF)

• Payer Type and Payer Source Codes (Excel)
  (Includes all information from FY21- FY25).