Chain transfer to polymer is a significant process in the polymerization of acrylate-type monomers.1??4 It is well accepted that intramolecular chain transfer to polymer (socalled backbiting) is favored over intermolecular chain transfer to polymer. It has been reported that chain transfer to polymer occurs primarily via a 1,5-hydrogen shift (Scheme S1, Supporting Information).5??7 It is important to note that intramolecular chain transfer to remote positions is also possible, though not favored. The result of chain transfer to polymer is an interesting situation in which two distinct transient radicals coexist in the system. The complexity and challenges posed by the coexistence of two distinct transient radicals in n-butyl acrylate (BA) polymerization becomes apparent in the kinetic description of its controlled radical polymerization. The prime focus of this Communication is to probe the kinetics of BA polymerization mediated by nitroxides, especially the implications on kinetics of the reversible deactivation of the tertiary mid-chain radicals (MCRs).