A blade outer air seal assembly includes a support structure. A blade outer air seal has a plurality of segments that extend circumferentially about an axis and mounted in the support structure. At least two of the segments have a first wall circumferentially spaced from a second wall. A base portion extends from the first wall to the second wall. A recess is arranged in at least one of the first wall and the second wall. An intersegment seal is arranged between the at least two segments. The intersegment seal has a circumferentially extending portion and a radially extending tab. The radially extending tab extends into the recess to define at least two cavities within the recess.