As of my last knowledge update in September 2021, the U.S. Army Service Uniform (ASU) has replaced the Army Dress Blues as the standard service uniform for the U.S. Army. The ASU includes different variations for different occasions, such as the blue service uniform, which is intended for more formal events.
The transition to the ASU was a gradual process, and the wear-out date for the green Class A and B uniforms (Dress Greens) was September 30, 2015. Soldiers are expected to wear the ASU for ceremonial and official functions. However, it’s essential to note that uniform regulations can be subject to updates and changes, so it’s recommended to check the latest information from official U.S. Army sources for the most current guidelines.