Story in Mass Effect Andromeda is covered on this page.
The game takes place in the Andromeda Galaxy, "far away from and long after the events of the original trilogy," and is "very much a new adventure." The primary protagonist is a human called Ryder. Unlike Commander Shepard, Ryder has yet to achieve "hero status" prior to the start of the game, and will undergo a narrative arc more akin to the traditional hero's journey. While the male and female Commander Shepards are different versions of the same character, male and female Ryders are different characters said to canonically exist as they are twin siblings traveling to Andromeda with their family, including their N7 father. If a player selects the female Ryder, the male Ryder would be somewhere else in the universe and vice versa. However, the non-selected Ryder will not be a squadmate. The fate and whereabouts of the mother Ryder will also be addressed.
The Ryder twins are named Scott and Sara by default. Their father is Pathfinder Alec Ryder.
The Ryders will be onboard the Hyperion, an Ark starship that has been sent to Andromeda as part of the Andromeda Initiative to find a new home for humanity. A coalition of races from the Milky Way are also present in the journey to Andromeda, distributed among four other Arks and led by the flagship Nexus, the Citadel analogue.
Known returning races from the franchise include asari, krogan, turians, and salarians. Species from the Milky Way not present in the expedition may be included in future installments. Introducing in this game are the kett, an organic native alien race covered in bone armor. They are the main antagonists in the Andromeda galaxy and their culture is very militaristic. Another introduced race is the angara.
Although there will be little to no reference to characters from the original trilogy, a few cameos are expected, but there will be no crew members from the previous games returning. Choices made in the original trilogy may be recognized, but will not be the main focus of the game. Player choices related to the ending of Mass Effect 3 will not be acknowledged nor will a canon ending be selected. The original trilogy is said to provide a "foundational background," but it is intended that Andromeda be accessible for players who haven't played the original trilogy.