An expandable fusion device (1000, 1000v) for implantation between two adjacent vertebrae, the device comprising: an actuator (500, 500v) comprising a drive feature and a longitudinal axis; a wedge assembly having a distal wedge and a proximal wedge and coupled to the actuator, the wedge assembly providing a width expansion of the device; a ramp assembly having a distal ramp and a proximal ramp and slidably coupled with the wedge assembly, the ramp assembly providing a height expansion of the device; an upper endplate assembly having a first endplate and a second endplate and slidably coupled with the ramp assembly; a lower endplate assembly having a third endplate and a fourth endplate and slidably coupled with the ramp assembly; a width comprising an external width of at least one of the upper endplate assembly and the lower endplate assembly; and, a height comprising an external distance between the upper endplate assembly and the lower endplate assembly; wherein, the device is configured such that actuation of the drive feature by a first number of actuations in a first actuation direction increases the width without increasing the height; actuation of the drive feature by a second number of actuations beyond the first number of actuations in the first actuation direction increases at least one of the height and the width; the distal wedge and the proximal wedge move toward one another and slide on the ramp assembly when actuating the drive feature; resulting in a width expansion; and, only after the width expansion that occurs as the distal wedge and the proximal wedge move toward one another and slide on the ramp assembly, the distal ramp and the proximal ramp then start moving toward one another when actuating the drive feature, resulting in a delayed height expansion. an actuator (500, 500v) comprising a drive feature and a longitudinal axis; a wedge assembly having a distal wedge and a proximal wedge and coupled to the actuator, the wedge assembly providing a width expansion of the device; a ramp assembly having a distal ramp and a proximal ramp and slidably coupled with the wedge assembly, the ramp assembly providing a height expansion of the device; an upper endplate assembly having a first endplate and a second endplate and slidably coupled with the ramp assembly; a lower endplate assembly having a third endplate and a fourth endplate and slidably coupled with the ramp assembly; a width comprising an external width of at least one of the upper endplate assembly and the lower endplate assembly; and, a height comprising an external distance between the upper endplate assembly and the lower endplate assembly; wherein, the device is configured such that actuation of the drive feature by a first number of actuations in a first actuation direction increases the width without increasing the height; actuation of the drive feature by a second number of actuations beyond the first number of actuations in the first actuation direction increases at least one of the height and the width; the distal wedge and the proximal wedge move toward one another and slide on the ramp assembly when actuating the drive feature; resulting in a width expansion; and, only after the width expansion that occurs as the distal wedge and the proximal wedge move toward one another and slide on the ramp assembly, the distal ramp and the proximal ramp then start moving toward one another when actuating the drive feature, resulting in a delayed height expansion.