The touring company's success emboldened the Busfields to expand. In 1991, they created the B Street Theatre mainstage, producing plays for adult audiences in Sacramento. The programming was deliberately adventurous -- most productions each season were world, national, West Coast, or regional premieres, not safe revivals of familiar Broadway hits. Sacramento responded. The Sacramento News & Review named B Street the city's Best Live Theatre for fourteen consecutive years. Sacramento Magazine honored it as Best Performing Arts Organization thirteen times. By the time the mainstage hit its stride, approximately 70,000 adults were attending performances each year, drawn by a repertoire that favored the new and the untested over the familiar.

The School Tour remains the backbone of B Street's mission, and its scale is staggering. Twelve performances a week, thirty-eight weeks a year, with an average audience of 450 children per show. The company makes a deliberate effort to reach underserved communities, ensuring that economic barriers do not determine which children experience live storytelling. Beyond performances, B Street runs an annual playwriting festival and contest for students, asking children not just to watch theatre but to create it. The workshops teach literary skills and problem-solving through dramatic writing, and the contest gives young playwrights a public stage for their work. In 2002, B Street added a Family Series -- professional productions designed for school field trips during the week and the general public on weekends, with curriculum materials developed for each show so that teachers can weave the experience into their classrooms.

For years, B Street operated out of modest spaces that couldn't keep pace with demand. That changed when Sutter Medical Center provided a land grant at 27th and Capitol Avenue in midtown Sacramento. The result was The Sofia Tsakopoulos Center for the Arts, which opened in February 2018. Local architect Ron Vrilakas designed the complex as a deliberate contrast to the intimidating formality of many performing arts venues -- the ethos was "come as you are." The Mike & Bobbie Voris Mainstage, a 250-seat thrust-style theatre, anchors the building. Next to it sits the Sutter Theatre for Children, a 365-seat proscenium space -- three times the capacity of the old children's theatre, capable of serving an additional 30,000 young audience members each year. Sutter Children's Hospital stands directly across the street, deepening a partnership that explores what theatre can do for patients and their families.

The Sofia quickly became more than a home for B Street. Its large public lobby, classrooms, open-air courtyard, and on-site restaurant turned the building into a midtown destination that hosts performances, comedy, dance, and musical acts from visiting artists and community organizations every night of the year. B Street's "Upstairs at the B" program gives artists-in-residence a flexible space to curate and create, with production guidance from the company. The conservatory trains adult actors, while the Studio for Young Actors offers year-round education for students ages seven to seventeen, taught by B Street company members with extensive regional and national credits. An intensive ten-month acting internship gives recent college graduates their first professional theatre experience, embedding them in every aspect of the operation from backstage rigging to front-of-house management.