With the ever increasing demands in higher data rate, there is a growing interest in exploiting the millimeter wave (mmWave) spectrum for future access communications. Aiming at characterizing the mmWave indoor propagation channel, a wideband measurement campaign using directional antennas has been conducted at 73 GHz in New York City in an office-type environment. In addition, ray-tracing using a database with the same environment has been performed to predict channel parameter statistics in conjunction with the measured data. A preliminary 3GPP-like 3D mmWave indoor channel model is proposed including the distance-dependent elevation model. The estimated channel characteristics such as delay spread and angular spread are validated with the measurements. The proposed channel model can be used in simulating mmWave indoor communications in office-type environments using multi-input multi-output (MIMO) antenna arrays.