Background There is a need for mentoring interventions in which transition‐age youth and young adults with intellectual and/or developmental disabilities (I/DD) participate as both mentors and mentees. Project TEAM (Teens making Environment and Activity Modifications) is a problem‐solving intervention that includes an electronic peer‐mentoring component. Methods Forty‐two mentees and nine mentors with I/DD participated. The present authors analysed recorded peer‐mentoring calls and field notes for mentee engagement, mentor achievement of objectives and supports needed to implement peer mentoring. Results Overall, mentees attended 87% of scheduled calls and actively engaged during 94% of call objectives. Across all mentoring dyads, mentors achieved 87% of objectives and there was a significant relationship between the use of supports (mentoring script, direct supervision) and fidelity. Conclusions Transition‐age mentees with I/DD can engage in electronic peer mentoring to further practice problem‐solving skills. Mentors with I/DD can implement electronic peer mentoring when trained personnel provide supports and individualized job accommodations.