Z-Code documentation of Social Determinants of Health Among Medicaid Beneficiaries, 2016-2022

Social determinants of health are important drivers of health-related social needs (HRSN), affecting health outcomes and health disparities. Medicaid beneficiaries have a high burden of HRSN. Z-codes were incorporated in the 10th revision of the International Classification of Diseases in 2015 to document HRSN in electronic health records and claims. This study characterized trends in Z-codes documented in Medicaid claims nationally from 2016 to 2022.

Medicaid claims data from the 2016-2022 Transformed Medicaid Statistical Information System Analytic Files were analyzed in 2024-2026. States with unusable data in the study period (MD, MS, RI, TN) were excluded. An indicator was created for Z-code use in any diagnosis code field in all service settings, and categorized Z-code claims by Z-code subtype (Z55-Z65, e.g., problems with housing). The percentage of Medicaid beneficiaries with any Z-code claim, overall and stratified by state, and the percentage of claims with each Z-code subtype overall over time were calculated.

The percentage of beneficiaries with a Z-code claim was 1.15% in 2016 and 1.66% in 2022. In 45 of 46 included states, the percentage of Medicaid beneficiaries with a Z-code claim was <5% across years. Among Z-code claims, problems with housing and economic circumstances were the most documented HRSNs, ranging from 36.8% to 66.3% of Z-code claims across years.

Z-codes for HRSN were rarely used in 2016-2022 Medicaid claims across 46 states with usable data, underrepresenting HSRN in this population. Limited use in claims may be driven by lack of reimbursement for Z-codes.