A retainer clip for a compression post includes a retainer body defining a first lateral body end, a second lateral body end opposite the first lateral end, a retainer opening formed through the retainer body and positioned between the first and second lateral body ends, and a retainer tab extending into the retainer opening; and a substantially J-shaped ledge grip extending from the first lateral body end, the ledge grip defining a curved portion and a planar portion, the curved portion coupled to the first lateral body end, the planar portion extending from the curved portion distal to the first lateral body end, the planar portion extending beneath the retainer body.