Background. Elevated distress is common in the context of cancer, which left untreated has psychological and physical health implications. Efficacious interventions exist, such as cognitive behavioral stress management (CBSM), however, multiple access barriers persist (e.g., resource shortages, contextual barriers, privacy concerns). Digitizing treatments may improve access. A double-blind, randomized controlled trial (RESTORE) found those assigned to an app-based version of CBSM experienced significantly greater reductions in anxiety and depression symptoms over 12 weeks versus those assigned to a health education (HE) sham app. However, the long-term benefits of the digitized CBSM program are unknown. Methods. Patients with stage I-III cancer within 6 months of active treatment were recruited nationwide for the RESTORE trial and were subsequently invited to reconsent for a follow-up study that assessed the trial outcomes at 6- and 9-months post-baseline. The primary outcome of change in anxiety symptoms (PROMIS-Anxiety SF) and the top secondary outcome of change in depression symptoms (PROMIS-Depression SF) were analyzed using mixed-effects modeling with repeated measures (weeks 0, 4, 8, 12; months 6, 9). A post-hoc contrast test compared estimated marginal means at 6 and 9 months. Results. Analyses were conducted with the intention-to-treat sample (N=449; age M [SD]=52.44 [11.46]; 81% female; 76% White; 53% breast cancer); n=230 and n=226 provided 6 and 9-month follow-up data, respectively. There were no significant differences (p<.05) between participants only in the main study and those who enrolled in the follow-up study in baseline PROMIS-A/PROMIS-D scores nor demographic variables, with the exception of more females in the follow-up. Patients assigned to CBSM showed greater reductions in anxiety (B=-0.03; p=.018) and depression (B=-0.02; p=.041) symptoms over 9 months (vs HE). At 6 and 9 months, CBSM participants had clinically meaningful lower levels of depression and anxiety symptoms (3-5pt range) compared to HE (estimated marginal means: 6-month PROMIS-A CBSM=54.1 (se=0.93) vs HE=57.2 (se=0.85), p=0.02; 6-month PROMIS-D CBSM=50.6 (se=0.92) vs HE=53.7 (se=0.84), p=0.02; 9-month PROMIS-A CBSM=50.3 (se=1.6) vs HE=55.4 (se=1.4), p=0.01; 9-month PROMIS-D CBSM=46.9 (se=1.5) vs HE=51.9 (se=1.4), p=0.02). Conclusion. Use of digitized CBSM showed anxiety and depression benefits over 9 months, supporting durability of the 10-session self-directed program.