A zoom lens has, in order from an object side, a focusing unit including a focusing lens group moving for focusing, a variable magnification unit including at least two variable magnification lens groups moving while changing a mutual interval for variable magnification, an aperture stop, and an image forming unit including an image forming lens group. The image forming unit consists of, in order from the object side, an M1 lens group, an M2N lens group, and an M3 lens group. The M2N lens group is replaceable with an M2E lens group that enlarges an image forming magnification. The M2E lens group satisfies predetermined conditional expressions (1) to (4).