Altogether, 39.7%( n=119) could be considered sexual minority at one or more time points based on identity and/or behavior 16.3%( n=49) reported shifts in sexual identity. This study examined different methods of accounting for sexual orientation in a cohort study of 300 homeless and unstably-housed women followed every 6 months over 3 years. Sexual orientation has been linked to certain health conditions, yet quantifying sexual orientation in longitudinal studies is challenging.