We present models for the ultrawideband (UWB) channel delay profile in indoor environments, based on the processing of two large sets of measured data. Both measurement sets are for a center frequency of 5 GHz, but the bandwidths are very different-1.25 GHz and 6 GHz. We model both line-of-sight (LOS) and nonline-of-sight (NLOS) paths, and do so for both single-family homes and commercial buildings. Also, we consider both the profile at a receiver point, which we call the multipath intensity profile (MIP), and the locally spatially averaged profile, which we call the power delay profile (PDP). For both cases, we find that the profile for NLOS paths can be modeled as a decaying exponential times a noise-like variation with lognormal statistics and that, for LOS paths, the profile has the same form plus a strong component at the minimum delay. The model consists of statistical descriptions of the parameters of these functions, including the effects of transmit-receive (T--R) distance and of variations from building to building. We show simulation results for a few cases to demonstrate that the model accurately predicts key properties of the measured channels, such as the distribution of rms delay spread.