[10] During the offseason, following meetings between head coach Filippo Milano and owner Giuseppe Pezzano, the team re-branded to OSA FC with plans to integrate more Italian talent alongside young American players.

[11][12] The newly branded team finished the 2016 NPSL season first in the Northwest Conference for a second straight year, defeating Portland Spartans FC, 2–1, on July 2.

Prior to the 2015 regular season's start Tacoma played its inaugural match on February 20, 2015 in a qualifier for the 2015 Lamar Hunt U.S. Open Cup, in which they defeated fellow Northwest Conference team and Oregon-based Spartans Futbol Club, 2–1, at Starfire Sports.

[16] On March 22, 2015, In its second match, FC Tacoma beat Southwest Conference representative San Diego Flash, 6–1, at Memorial Stadium (Seattle), and officially qualified for the 2015 U.S. Open Cup.

A week later in the second round, the team played to a second straight penalty kick shootout against United Soccer League side Reno 1868 FC where it lost, 1-1 (3-4).