We observe that stimulated emission from inhomogeneously pumped quantum well laser diodes is shifted down in energy compared with the subband transition energy. Measured spontaneous emission spectra show that this stimulated emission is due to band‐to‐band transitions shifted by renormalization at high injected carrier densities, and we suggest that this same mechanism explains reported observations of stimulated emission from inhomogeneously photopumped structures which previously have been interpreted as evidence for longitudinal optic (LO) phonon participation. We show that LO phonon participation cannot account for the photon energy of stimulated emission from conventional homogeneously pumped quantum well laser diodes.