Question: is mass effect andromeda set after mass effect 3

Answer: No, Mass Effect: Andromeda begins in 2185, between the events of Mass Effect 2 and Mass Effect 3. The four Citadel Council races and the Quarians are planning to populate new home worlds in the Andromeda Galaxy as part of a strategy called the Andromeda Initiative. Each race sends 20,000 citizens on a one-way, 600-year journey to Andromeda aboard their own transportation vessel, called an Ark, and selects a leader, known as a Pathfinder. Once the races arrive, they help build the Nexus, a space station that serves as a center of government and diplomacy, a living area, as well as a base of operations for the Pathfinders.