How does USCIS make decisions around promotions?

USCIS, like other federal agencies, has a few different mechanisms for promotions. Depending on the position you’re hired into you may be eligible for grade increases up to the maximum level in the announcement. You are also likely eligible for step or quality step increases (QSI). For the most part, aside from the QSI each of these are automatic in accordance with law & agency regulations as long as you meet the time requirements and have acceptable performance. In certain conditions these may not be automatic. The schedule for step increases is available online and is uniform across much of the government. Aside from grade and step increases you are also eligible to apply to promotion opportunities once you have the time in grade and met the requirements for the new position. You apply to these promotions/positions like any other.