Postfabricated beams, that is, newly constructed beams in an existing structural system, provide an effective remedial solution to the serviceability and strength problems in an existing floor system and the discontinuities and irregularities in the seismic-force-resisting system of a structure, mostly caused by design and construction errors or intended omissions of certain members. The purpose of this study is to develop new techniques for postfabrication of these beams and connecting the postfabricated beams to the existing columns and slab. In this respect, an experimental study was planned and a total of 16half-scale specimens, including 3 monolithic (slab, columns, and beams cast monolithically) specimens and 13 specimens with postfabricated beams, were tested under monotonic vertical loads. The longitudinal reinforcement ratio of the postfabricated beam and the connection techniques of the postfabricated beam to the surrounding columns and slab constituted the test parameters. The tests indicated that the specimens with postfabricated beams were able to reach the strength and behavior of the monolithic specimens.