Successful growth of 1.3 and 1.55 mu m GaInAsP/InP multiquantum well lasers directly on a distributed feedback (DFB) grating substrate using all solid-source molecular beam epitaxy was demonstrated. A 1.12 mu m wavelength GaInAsP planarization layer with a nominal thickness of 500-650 Angstrom was first grown on the DFB gratings at an elevated temperature to create a smooth surface for subsequent layer growth. Transmission electron micrograph showed smooth interfaces after the growth of this GaInAsP planarization layer. Low threshold current density and high quantum efficiency were obtained from these index-coupled DFB lasers.