The Deaconess Billings Clinic Psychiatric Center, built in 1987, was designed to accommodate the increased demand for long-term psychiatric care in a less institutional environment than the hospital. Constructed on a full-city block immediately adjacent to the hospital complex, the 47,000 sf building is a single-story structure with a partial basement.

Linked to the main hospital with a skybridge over the street, the floor plan has a tic-tac-toe configuration which provided maximum exterior exposure for windows while reducing the massing of the building in response to the residential neighborhood surrounding it. The plan was design for a mix of patients including secure, closed, and open adults and closed and open adolescents. From the administrative entrance at the northwest corner of the building, patients and guests are escorted to either the adult or adolescent areas via the central corridor system while maintaining a separation of patients types. The main corridors have a series of cross-corridor doors which can increase or decrease the number of patient rooms within a particular segment of the building as the population fluctuates.

Common facilities designed for use by all patients include a gymnasium, a swimming pool, and a cafeteria. The central courtyard provides a secure outdoor activity area as well.

The building is constructed with a slab-on-grade floor, steel frame wall and roof structure and is non-combustible throughout. The exterior was clad with aluminum metal panels over a granite veneer base. The roof is a single-ply membrane punctuated by skylights over the nurse stations at the corridor intersections.