1. Completion of an accredited certification training
• Scope: Minimum of 40 hours of didactic education within an ISST-approved program.

• Composition: The training typically consists of 25 hours of theory (didactics) and 15 hours of skills practice (dyadic training).
• Instruction: Training must be led by an ISST-accredited trainer associated with the specific training program.

2. Supervision
Supervision must last at least one year and be conducted by a certified ISST Trainer/Supervisor.
• Standard Level: Minimum of 20 hours of individual supervision (50–60 minutes each).
• Advanced Level: Minimum of 40 hours of individual supervision.
• Recordings: The supervisor must additionally view session recordings (2 hours for Standard, 4 hours for Advanced), which do not count toward the basic supervision hours.

• Self-therapy: ISST recommends some self-experience of Schema therapy as part of the supervision process (max. of 3 sessions for Standard and max. of 6 sessions for Advanced certification).

3. Clinical Practice
• Standard Level: Treating at least 2 patients for a minimum of 25 hours of schema therapy each (total min. 80 sessions). One patient must have a personality disorder diagnosis or significant traits.
• Advanced Level: Treating at least 4 patients for a minimum of 25 hours each (total min. 160 sessions). One patient must have a Borderline Personality Disorder (BPD) diagnosis or strong BPD traits, and the second must have a different personality disorder.

4. Independent Rating of Recordings
The candidate submits recordings of full sessions along with a case conceptualization to an independent certified rater.
• Standard Level: 1 recording rated with an average score of at least 4.0 on the STCRS scale.
• Advanced Level: 2 recordings (each with a different patient) with an average score of at least 4.5 on the STCRS scale.

5. Time Limits and Administration
Deadline: The application for certification must be submitted within 3 years of completing the basic training.