Objectives: Older adults with mental health problems may benefit from psychotherapy; however, their perceived need for treatment in relation with rates of non-utilization of outpatient psychotherapy as well as predisposing, enabling, and need factors proposed by Andersen’s Model of Health Care Utilization that account for these differences warrants further investigation.Method: We used two separate cohorts (2014 and 2019) of a German weighted nationwide telephone survey of German-speaking adults with N=12,197 participants. Across the two cohorts, 12.9% (weighted) reported perceived need for treatment for mental health problems and were selected for further analyses. Logistic Generalized Estimation Equations (GEE) was applied to model the associations between disposing (age, gender, single habiting, rural residency), enabling (education, general practitioner visit, general health status) non-utilization of psychotherapy (outcome) across cohorts in those with need for treatment (need factor).Results: In 2014/2019, out of 6,087/6,110 participants, 11.8%/14.0% reported perceived need for treatment due to mental health problems, which reflects a significant increase in prevalence from 2014 to 2019. Of those who reported perceived need for treatment, 36.4%/36.9% did not see a psychotherapist – where rates of non-utilization of psychotherapy were vastly higher in the oldest age (59.3/52.5%; 75+) category, than in the youngest (29.1/10.7%; 18-25 years). Concerning factors associated with non-utilization, multivariate findings indicated participation in the cohort of 2014 (OR 0.94), older age (Age 55-64 OR 1.02, Age 65-74 OR 1.47, Age 75+ OR 4.76), male gender (OR 0.83), lower educational status (OR 0.84), rural residency (OR 1.38), single habiting (OR 1.37), and seeing a GP (OR 1.39) to be related with non-utilization of psychotherapy; general health status was not significantly associated with non-utilization when GP contact was included in the model.Conclusion: There is a strong age effect in terms of non-utilization of outpatient psychotherapy. Individual characteristics of both healthcare professionals and patients and structural barriers may add to this picture. Effective strategies to increase psychotherapy rates in those older adults with unmet needs for treatment are required.