Professor Gonzales uses large, nationally representative surveys to monitor health disparities and to measure the impact of federal and state policy changes on health outcomes for LGBTQ+ populations.

Originating in an era without large-scale data on sexual orientation or gender identity (SOGI), Professor Gonzales' research started with studying same-sex couples in census data. Then, as national surveys began collecting SOGI data, his research explored new and groundbreaking topics in LGBTQ+ health.

Professor Gonzales also conducts research examining the impacts of the Affordable Care Act (ACA) and other health care reforms on vulnerable populations, including low-income families, racial and ethnic minorities, and populations living with mental illness. Collaborating with other scholars, Professor Gonzales has documented that public health insurance expansions through Medicaid increased health insurance coverage and reduced out-of-pocket medical spending for low-income families and individuals, particularly for individuals living with mental illness or psychological distress.

A third theme of Professor Gonzales' research focuses on disparities in health care and the social determinants of health (SDoH) among vulnerable children, youth, and adolescents. Building on top of his LGBTQ+ health research, he developed and led new explorations on access to care for children with LGBTQ parents. He has also researched how the social determinants of health (SDoH) and adverse childhood experiences (ACEs) affect health outcomes among children in the United States.