Thumb reconstruction aims to restore the cardinal thumb traits and actions including mobility, stability, sensibility, length, and appearance. The level of thumb loss is divided into thirds: distal (tip to interphalangeal [IP] joint), middle (IP joint to metacarpal neck), and proximal (metacarpal neck to carpometacarpal joint). Distal third reconstruction usually requires only soft tissue restoration. Many options exist for middle third reconstruction, including increasing thumb ray length (metacarpal lengthening, osteoplastic reconstruction, toe transfer) and increasing relative length (phalangization). Proximal third reconstruction is best accomplished with toe transfer, pollicization, or on-top plasty (pollicization of a damaged index finger).