The current context of standards-based reform has positioned regional service centers (RSCs), intermediary governmental agencies that support state policy implementation in local districts, as a critical source of professional development (PD). In this article, we ask how a governing body that districts often interact with during challenging reform processes manages maintain strong relationships with district and school staff, and thus maintain their image as trustworthy experts on standards implementation. We explore these questions using data from 108 interviews of state, district, and regional administrators in education agencies in Ohio, Texas, and California over a three-year period. We illustrate that by providing districts with (a) differentiated support specific to their unique needs, (b) materials and tools consistent with state content standards, and (c) expertise in supporting students with disabilities and English learners in standards-based environments, RSC staff become, in the words of one state leader, the state's trusted "boots on the ground." [For the corresponding grantee submission, see ED616594.]