Sexual and gender minoritized (SGM) adolescents negotiate their outness in various social contexts as they navigate a heteronormative system. For many SGM adolescents, outness is associated with peer victimization, while for others, it is associated with increased feelings of connectedness. To support SGM adolescents in their outness journey, researchers and practitioners often use various tools to measure outness. Specifically, the outness inventory (OI) is the oldest and most widely used outness measure to date. However, while the OI appears to be a vigorous inventory to measure outness among SGM adults, it has never been validated with an SGM adolescent population. This study tests the psychometric defensibility of the OI among an SGM adolescent population. Results provide evidence that a two-structure model of outness to family and world, represents the social contexts in which SGM adolescents negotiate outness.