Identifying Medicare Beneficiaries Accessing Transgender-Related Care in the Era of ICD-10

The study purpose was to describe trends in the size and demographics of the population of transgender Medicare beneficiaries identified using International Classification of Diseases (ICD) Clinical Modification codes over time. We also assessed how the change from ICD, Ninth Revision (ICD-9) diagnosis codes to ICD, 10th Revision (ICD-10) diagnosis codes in October 2015 has affected the ability to identify transgender beneficiaries within claims data. We used Medicare Fee-for-Service claims within the Centers for Medicare & Medicaid Services Chronic Conditions Data Warehouse from 2010 through 2016 to identify transgender beneficiaries. We linked these data to Medicare enrollment records to study demographic trends. Within the Medicare program, the number of beneficiaries identified as transgender through claims data in each year has increased from 2088 beneficiaries in 2010 to 10,242 beneficiaries in 2016 (a 390% increase). The highest numbers of transgender beneficiaries were identified in 2015 and 2016, which coincide with the change to ICD-10. Similarly, more beneficiaries were identified as transgender in the 12 months after the change to ICD-10 (N = 8733) than in the 12 months before (N = 4857). Given that a first and critical step to better understand and eliminate health disparities and deliver culturally competent care is to identify and characterize the population of interest, this study provides an innovative view into how the change to the ICD-10 coding system affects the ability to study a transgender cohort within Medicare claims data.