Under-Documentation of Z-Codes in Hospitalizations of Homeless Shelter Users in New York City

To assess documentation of social risk International Classification of Diseases, 10th Revision (ICD-10) Z-codes among hospitalized homeless shelter users in New York City (NYC).

Cross-sectional analysis of hospitalizations among individuals experiencing homelessness using 2019 statewide administrative data from New York.

New York Statewide Planning and Research Cooperative System (SPARCS) inpatient discharge data linked to NYC homeless shelter addresses. Hospitalizations were identified by matching geocoded discharge addresses to shelter locations (n = 13,105).

Among 13,105 hospitalizations, 27% had at least one Z-code documented and 23% included a homelessness Z-code. In adjusted analyses accounting for hospital-level clustering, documentation was highest for mental and behavioral health hospitalizations and lowest for maternal health admissions. Documentation was lower among women, younger patients, racial and ethnic minority groups, privately insured patients, and patients treated in private nonacademic hospitals.

Z-code documentation among hospitalized individuals experiencing homelessness is low and varies across clinical, demographic, and institutional groups. Improving documentation completeness is important as reimbursement and equity-focused policies increasingly rely on accurate Z-code capture.