We describe the electrochemical α-amidoalkylation of γ-lactams based on transition-metal-free cross-coupling via hydrogen atom transfer. The highly selective hydrogen atom transfer process allows for a broad substrate scope including both inter- and intramolecular reactions. Also, the construction of quaternary centers was realized by a double hydrogen atom transfer protocol to afford spirocycles. Detailed mechanistic studies including experimental and computational studies are provided to support the reaction pathway.