A blade outer air seal assembly includes a seal segment that has a base portion that extends between a first circumferential side and a second circumferential side and from a first axial side to a second axial side. A first wall is axially spaced from a second wall. The first and second walls extend from the base portion to an outer wall to define a circumferentially extending seal passage. A carrier has a platform. A portion of the platform is within the seal passage. A radially extending first hook protrudes from the platform and is configured to engage with a support structure.