Co‐construction theory suggests adolescents use digital communication to address developmental challenges. For a sample of 214 ethnically diverse adolescents, this research used direct observation to investigate the frequency, content, and timing of texting with parents, peers, and romantic partners through grades 9–12. Analyses showed that texting frequency follows a curvilinear trajectory, peaking in eleventh grade. Adolescents discussed a range of topics, predominantly with peers. Communication with parents was less frequent, but consistent over time. Approximately 45‐65% of adolescents communicated with romantic partners, texting heavily and about topics similar to those discussed with peers. Texting may help adolescents navigate key developmental challenges of adolescence—the establishment of autonomy, intimate peer relationships, romantic relationships, and self‐identity.