Using case studies of four schools in three districts, this article explores how leadership is distributed in districts and asks about the role of teacher leaders. It proposes that teacher leaders and districts can share three leadership tasks: procuring and distributing materials, monitoring improvement, and developing people. The district and teacher leaders play complementary roles. How effective teacher leaders are at people development will depend on the time they have, the knowledge they have, and their monitoring responsibility. These conditions depend partly on administrative support, indicating districts may have more opportunity to influence teaching practice than past research had indicated. (Contains 2 tables and 2 footnotes.)