"The New York City Department of Probation (DOP)-the second largest probation department in the country-is advancing a process to infuse evidence-based policies and practices (EBPP) throughout the organization ... What is significant for the purpose of this story is that the Federal agencies were able to thoughtfully, strategically, respectfully, and effectively apply the right dosage of technical assistance to the moving train in a way that made the most of the investment and the capacity that BJA and NIC had to marshal for the city" (p. 3-4). This brief explains how the NYC DOP Adult Operations Division partnered with the U.S. Bureau of Justice Assistance (BJA) and the National Institute of Correction (NIC) to create an organizational culture within the division that was committed to using evidence-based practices. Lessons learned from this collaboration are also covered. This document is comprised of six sections: what the BJA and NIC technical assistance providers worked on with DOP, and how their work fit with other pilot programs, initiatives, and philanthropic support; what is unique about DOP from the perspective of Federal agencies that engage in technical assistance with local agencies; what is unique about what the partners brought to the table, what kind of technical assistance approach they developed together, and how it was managed and delivered; how the Federal agencies’ technical assistance advanced DOP’s EBPP goals; where New York City’s DOP evidence-based practice work is taking the department; and conclusion--what the rest of the field can learn from the DOP, BJA, and NIC technical assistance collaborative partnership, and why it does matter.