In 1994, after years of teaching privately, Rossi established Youth Advancement through Music & Art (YATMA, a nonprofit) in Seattle, WA. As executive director he partnered with such diverse organizations as Harborview Medical Center, the Seattle Art Museum, Seattle Children’s Home, and Langston Hughes Cultural Center to deliver after school arts mentoring to over 1,500 challenged youth. YATMA received substantial foundation support, including the Bill and Melinda Gates Foundation and numerous other national and local funders.

In 2000, Rossi replicated YATMA at Parsons Child & Family Center in Albany, NY, a therapeutic treatment facility with a focus on Post Traumatic Syndrome Disorder (PTSD) where YATMA services were designated as a component of the clients’ Therapeutic Treatment Plan.

In 2004, YATMA received a grant from the National Endowment for the Arts (NEA) to develop his best practice after school program within St. Anne Institute in Albany, a residential treatment facility for adjudicated young women. At this time, YATMA changed its name to EMTAH (Educational Mentoring through the Arts & Humanities).

After these years of research and active collaboration with other professionals in the field, Rossi took a sabbatical to create the Arts Mentoring Toolkit that includes SETS: Student Evaluation & Tracking System, the first evaluation software specifically designed for after school programs, and Venturing Together: Empowering Students to Succeed, the primer on his educational approach. In 2008 he and his wife Mary-Helen founded Merge to disseminate these materials.

Bill and Mary-Helen then relocated to the Philadelphia exurbs to integrate all of Rossi's best practice program components. While there, Rossi further developed his community building model, trained other educators in the Strengths-Based Mentoring Approach, implemented an after-school program for challenged youth, and collaborated with the county's workforce development program to engage their students.

An interesting side note: Bill is a creative learner who as a child was put at risk by teachers who deemed him unable to learn, and a prime example of the natural resources in our communities that so often go undeveloped. Were it not for a music teacher who steadily mentored him for years Bill might have gone the dead-end route of so many others like him, but this one person gave him a new perspective on life and the confidence that he had the inner intelligence and power to self-educate. And so he did.

His journey into self-education led him into a spiritual practice he's maintained since the late 1960s which includes meditation and contemplation leading to self-understanding. Rossi attributes the effectiveness of his approach to this practice.