Yes, you can absolutely change altitude while receiving VFR Flight Following from Air Traffic Control (ATC) in 2026, but the protocol depends on the airspace. In most "Class E or G" (uncontrolled or general) airspace, you are still flying under Visual Flight Rules (VFR), meaning you are ultimately responsible for your own terrain and traffic separation; however, it is a high-value peer-to-peer "best practice" to inform the controller by saying, "Requesting altitude change to [New Altitude]." This allows the controller to update your "data block" on their radar screen and better predict potential traffic conflicts. If you are in Class B or C airspace, you are under more direct control and must receive a specific clearance before changing altitude. Generally, unless the controller has told you to "Maintain [Altitude]," your altitude is "at your discretion," but keeping the "partnership" with ATC strong by communicating your intentions ensures the highest level of safety and situational awareness for you and other aircraft in the vicinity.