The Fermilab 200 MeV Linac is scheduled to be upgraded to a 400 MeV Linac beginning in the Spring of 1993 [1]. We have designed beam diagnostics for the accelerator to expedite the commissioning and to facilitate the long‐term reliability of the machine. These diagnostics include: stripline beam position monitors, resistive wall‐current monitors, X‐Y‐U wire scanners, and various velocity and/or phase measurement devices, including bucnh‐length detectors fashioned after the work at the INR in Moscow [2]. This paper will discuss these devices and our plans fot the commissioning of the new Linac using these diagnostics.