Transgender and gender-nonbinary (trans/GNB) individuals are disproportionally affected by human immunodeficiency virus (HIV), yet they are not adequately represented in HIV research and often underserved in clinical care. By building on community strengths and addressing structural, psychological and biological challenges, we can improve the engagement of trans/GNB people in research and ultimately improve prevention, testing, and care for this population. Here, we review the current state of the science related to HIV for trans/GNB people and discuss next steps to expand research that aims to improve the lives and well-being of trans/GNB persons.