A bone fastener comprising: a head assembly including a receiver defining an implant cavity and a plurality of adjacent grooves (34, 42, 64), which includes a first, a second and a third groove (34, 64, 42) that are circumferentially disposed with an inner surface of the receiver and along a longitudinal axis thereof, wherein the second groove has a larger diameter relative to the first groove and the third groove and is disposed between the first groove and the third groove, and the first groove is positioned at a distal end of the receiver; a first ring expandable between a contracted orientation and an expanded orientation and configured for disposal within the first groove in the contracted orientation or within the second groove in the expanded orientation; a second ring expandable between a contracted orientation and an expanded interference orientation and configured for disposal within the third groove in the contracted orientation or within the second groove in the expanded interference orientation; a set screw assembly including a shaft configured to penetrate tissue and a head, and a crown disposed within the implant cavity and having a distal face engageable with the second ring to dispose the second ring adjacent the first ring, wherein the bone fastener is configured so that, when the head assembly is assembled with the screw shaft assembly, the head of the screw shaft assembly engages with the receiver causing the first ring to translate in a first direction from the first groove into the second groove such that the first ring is positionable and allowed to expand into the second groove in the expanded orientation, and when the head translates further into the receiver, the first ring passes over the head and resiliently contracts about the head within the second groove to provisionally capture the screw shaft assembly; wherein the bone fastener is further configured so that, after provisional capture of the screw shaft assembly, when the crown is manipulated in a second direction opposite the first direction, an end surface of the crown engages the second ring such that the second ring translates from the third groove into the second groove and resiliently expands into the second groove to the expanded interference orientation, and engages the first ring driving the first ring from the second groove into the first groove, wherein the second ring is oriented for abutting and/or contracting engagement with the first ring to resist and/or prevent translation of the first ring from the first groove into the second groove, thereby fixing the screw shaft assembly with the head assembly. a head assembly including a receiver defining an implant cavity and a plurality of adjacent grooves (34, 42, 64), which includes a first, a second and a third groove (34, 64, 42) that are circumferentially disposed with an inner surface of the receiver and along a longitudinal axis thereof, wherein the second groove has a larger diameter relative to the first groove and the third groove and is disposed between the first groove and the third groove, and the first groove is positioned at a distal end of the receiver; a first ring expandable between a contracted orientation and an expanded orientation and configured for disposal within the first groove in the contracted orientation or within the second groove in the expanded orientation; a second ring expandable between a contracted orientation and an expanded interference orientation and configured for disposal within the third groove in the contracted orientation or within the second groove in the expanded interference orientation; a set screw assembly including a shaft configured to penetrate tissue and a head, and a crown disposed within the implant cavity and having a distal face engageable with the second ring to dispose the second ring adjacent the first ring, wherein the bone fastener is configured so that, when the head assembly is assembled with the screw shaft assembly, the head of the screw shaft assembly engages with the receiver causing the first ring to translate in a first direction from the first groove into the second groove such that the first ring is positionable and allowed to expand into the second groove in the expanded orientation, and when the head translates further into the receiver, the first ring passes over the head and resiliently contracts about the head within the second groove to provisionally capture the screw shaft assembly; wherein the bone fastener is further configured so that, after provisional capture of the screw shaft assembly, when the crown is manipulated in a second direction opposite the first direction, an end surface of the crown engages the second ring such that the second ring translates from the third groove into the second groove and resiliently expands into the second groove to the expanded interference orientation, and engages the first ring driving the first ring from the second groove into the first groove, wherein the second ring is oriented for abutting and/or contracting engagement with the first ring to resist and/or prevent translation of the first ring from the first groove into the second groove, thereby fixing the screw shaft assembly with the head assembly.