Public managers' role in policy change, and particularly in policy formation, has been understudied, especially among middle and lower levels of management. By focusing on street-level management, which occupies the sole highest managerial position in frontline organizations, this study shifts attention to a process during which local street-level implementation adaptations are later formally adopted as a new policy instrument, termed here street-level policy innovation. This research develops an analytical framework derived from a street-level policy innovation in practice drawing from the case of the Free Sidewalk program in Mexico. The framework aids to identify street-level policy innovation by looking at three key processes: (1) The re-design of implementation arrangements to address implementation gaps; (2) The accumulation of evidence for the effectiveness of the newly introduced instrument; and (3) The adoption of the experimented instrument as a formal policy change. Street-level policy innovation echoes the well-established notion of bottom-up innovation in the public sector, however, is triggered by delivery efforts exercised on the ground in an attempt to address local implementation gaps. Alighting the role of frontline organizations as a setting to explore, experience, and experiment with new policy instruments which suggests new theoretical and practical insights into the understudied interstices between policymaking and public management.