Methods, systems, and devices for power backoff techniques for modulation schemes are described. A user equipment (UE) may receive an indication of a constellation distribution parameter and a modulation scheme to be used by the UE for an uplink message on an uplink channel. The UE may determine an uplink transmission power based at least in part on the indicated constellation distribution parameter and the indicated modulation scheme. The UE may transmit the uplink message using the indicated modulation scheme according to the determined uplink transmission power. In some examples, the UE may transmit a report indicating a power headroom parameter and an output power parameter based at least in part on the constellation distribution parameter.