The implementation of evidence-based psychotherapies often requires significant commitments of time and expense from mental health providers. Psychotherapy protocols with rapid and efficient training and supervision requirements may have higher levels of uptake in publicly funded clinics. Family-focused therapy (FFT) is a 4-month, 12-session treatment for bipolar and psychosis patients consisting of psychoeducation, communication training, and problem-solving skills training. In a pilot randomized trial, we compared two methods of training community clinicians in FFT: (a) high intensity (n = 24), consisting of a 6-hour in-person didactic workshop followed by telephone supervision for every session with training cases; or (b) low-intensity training (n = 23), consisting of a 4-hour online workshop covering the same material as the in-person workshop followed by telephone supervision after every third session with training cases. Of 47 clinician participants, 18 (11 randomly assigned to high intensity, 7 to low) enrolled 34 patients with mood or psychotic disorders (mean age 16.5 ± 2.0 years; 44.1% female) in an FFT implementation phase. Expert supervisors rated clinicians' fidelity to the FFT manual based on taped family sessions. We detected no differences in fidelity scores between clinicians in the two training conditions, nor did patients treated by clinicians in high- versus low-intensity training differ in end-of-treatment depression or mania symptoms. Levels of parent/offspring conflict improved in both conditions. Although based on a pilot study, the results suggest that low-intensity training of community clinicians in FFT is feasible and can result in rapid achievement of fidelity benchmarks without apparent loss of treatment efficacy.