A method of programming a non-volatile memory device may include performing a first programming operation including applying a program voltage to a memory cell and verifying the memory cell using a first verification voltage. A perturbation pulse may be applied to the memory cell to facilitate thermalization of charges in the memory cell if the memory cell passes the verification using the first verification voltage. The memory cell may be verified using a second verification voltage greater than the first verification voltage after the perturbation pulse is applied.