Two or more formats for Power Headroom (PH) and maximum transmit power (Pcmax), and corresponding mapping tables, are defined. For example, both 6-bit and 7-bit PH and Pcmax formats are defined. In many cases, particularly when operating in the higher frequency FR2 range, a 7-bit PH or Pcmax may be required to adequately convey power headroom information. Numerous trigger criteria are defined which may indicate that one or the other format is preferred. The format selection must be communicated to the network, and subsequent Power Headroom Reports (PHR) will utilize the selected format.