The present invention provides a spinal implant for placement between adjacent processes of the human spine. In some embodiments the spinal implant includes a spacer and one or more retention members. In some embodiments, the retention members are fixed relative to the spacer and in other embodiments the retention members are deployable from a first or compact or stowed position to a second or expanded or deployed position. In some embodiments the spacer is expandable from a first size to a second size. In some embodiments the spacer has a tapered body.