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Expression Logical Model (ELM) Issue Impacting eCQMs for the 2020 Performance Period

The Centers for Medicare & Medicaid Services (CMS) is providing information on an issue that impacts only the Expression Logical Model (ELM) files of three eligible clinician electronic clinical quality measure (eCQM) scoring and affects the 2020 performance period only.


An issue has been identified in the Expression Logical Model (ELM) for three eCQMs published with the 2019 Annual Update for use in the 2020 performance period. ELM is a machine-readable representation of an eCQM’s logic that allows implementers to directly incorporate measure logic into their systems. The issue relates to how the ELM handles missing timing values during the evaluation of measure logic.

Impacted Measures

  • CMS128v8 Anti-depressant Medication Management
  • CMS146v8 Appropriate Testing for Children with Pharyngitis
  • CMS56v8 Functional Status Assessment for Total Hip Replacement

Potential Impact

For users who implement ELM directly for measure calculation, this issue has the potential to impact measure scoring when certain time values are not present in the input data. The erroneous evaluation may result in an increase or decrease of cases that fall in the measure population that contains the affected logic.


CMS has published updated measure packages to correct the ELM files for the three impacted eCQMs. Each file contains annotations to identify changes. No other files within the packages have been changed. The new packages include patched versions of the ELM content contained within these JSON and XML files:

  • AntidepressantMedicationManagement-8.3.001 JSON
  • AntidepressantMedicationManagement-8.3.001 XML
  • AppropriateTestingforChildrenwithPharyngitis-8.2.001 JSON
  • AppropriateTestingforChildrenwithPharyngitis-8.2.001 XML
  • FunctionalStatusAssessmentforTotalHipReplacement-8.1.001 JSON
  • FunctionalStatusAssessmentforTotalHipReplacement-8.1.001 XML

The new packages are available on the Electronic Clinical Quality Improvement (eCQI) Resource Center. Providers or vendors who directly consume ELM to calculate eCQMs should review the updated files to determine if system updates are warranted. All impacted systems whose users report any of the three impacted measures should update their systems. Additional details and measure specific information can be reviewed in the ONC eCQM Known Issues Tracker.

For More Information

Last Updated: May 24, 2023