PreK–12.

Merrell's Strong Kids is not a single program, but a lineup of five age-specific social-emotional learning courses developed by a team of education and mental health specialists to span a child's entire time in school: from the preschool level through senior year. It is built around competencies that align with the CASEL model: understanding one's own emotions, managing anger and stress, resolving conflicts with peers, and building relationships.

The program helps children recognize and understand their emotions, cope with anger and anxiety, build relationships with peers, and act with more confidence in difficult situations. The developers view these skills as a foundation for broader success — not only personal and social, but also academic, such as improved school performance.

The idea is for it to be a "fun and simple way" to teach children social-emotional competence — an accessible, engaging format rather than a heavyweight theoretical program. Instead of talking about feelings, the program provides concrete, practiced skills that fit into a regular school schedule without requiring special teacher training or additional infrastructure.

Each of the five programs in the series runs for 12 weeks. One session lasts about 20 minutes and can be split into shorter segments if needed.

An exact, current figure is not listed on the official website.

An exact list of countries or regions of distribution is not specified on the official website, brookespublishing.com.

The program's primary language is English. The official website does not directly indicate any other localized languages.

The program is included in the CASEL Program Guide registry with a status of Promising.

A 2010 quasi-experimental study of 106 students in grades 3–4 (northwestern United States) found increased knowledge and use of SEL skills and positive coping strategies, with the effect persisting for another 2 months after the program ended.

A 2014 quasi-experimental study of 614 students in grades K–6 (western United States, Title I schools) found a reduction in internalizing behaviors (loneliness, depressive symptoms) as rated by teachers.