An instrument sterile adapter (310) couples a surgical instrument (120) and an instrument carriage (130). The instrument sterile adapter (310) includes an instrument plate (430) that provides a first surface to receive the surgical instrument (120) and a latch plate (400) joined to the instrument plate (430). The latch plate (400) includes a second surface to receive the instrument carriage (130) and latch structures. Each latch structure has a carriage latch arm (410) that extends away from the second surface of the latch plate (400) and an instrument latch arm (405) joined to the carriage latch arm (410). The instrument latch arm (405) extends through the instrument plate (430) and away from the first surface of the instrument plate (430). A connecting member (425) flexibly connects the carriage latch arm (410) and the instrument latch arm (405) to a remainder of the latch plate (400). The connecting member (425) may be perpendicular to the latch arms (405). The latch arms (405) may engage fixed locking surfaces in the instrument carriage (130) and the surgical instrument (120).