An image forming apparatus includes an intermediate transfer unit, a secondary transfer unit, and a positioner. The intermediate transfer unit includes an intermediate transferor to bear an image. The secondary transfer unit includes a secondary transfer member to transfer the image borne by the intermediate transferor to a medium. The positioner positions the secondary transfer unit with respect to the intermediate transfer unit. The positioner includes a first member and a second member. The first member is disposed in the intermediate transfer unit. The second member is attachable to and detachable from the secondary transfer unit.