In the United States Army, Marine Corps, Air Force and Space Force, colonel () is the most senior field grade military officer rank, immediately above the rank of lieutenant colonel and just below the rank of brigadier general. It is equivalent to the naval rank of captain in the other uniformed services. By law, an officer previously required at least 22 years of cumulative service and a minimum of three years as a lieutenant colonel before being promoted to colonel. With the signing of the National Defense Authorization Act of 2019 (NDAA 2019), military services now have the authorization to directly commission new officers up to the rank of colonel. The pay grade for colonel is O-6.