Objective: To examine state variation in credentialing requirements for peer support specialists (PSSs) providing Medicaid-covered substance use disorder services.

Methods: A systematic search identified PSS credentialing requirements in 40 states. Requirements were analyzed across 10 credentialing components, including education, training, work experience, examinations, and certification maintenance.

Results: Credentialing requirements varied widely across states. Most required lived experience with substance use (95%), a high school diploma or equivalent (85%), and an examination (95%). Training requirements ranged from 30 to 80 hours, work experience requirements from 40 to 1,000 hours, and continuing education requirements from 8 to 40 hours. Certification periods and fees also differed substantially.

Conclusions: Significant variation exists in state PSS credentialing standards, highlighting the need for greater transparency, evaluation, and harmonization to support workforce development and service delivery.