Nonprofit organizations, private foundations, and for-profit corporations interested in shaping public education regularly partner with charter schools in New York. State law allows charter schools to pursue external partners to help meet their fiscal, facilities, operational, and instructional needs. This qualitative study of 10 schools in New York City examines how the relationship between charter school and external partner affects school autonomy and the school's relationships with teachers, parents, and community members. Data were collected through interviews with school staff and representatives of partner organizations, and through observations of meetings, daily school operations, and school-related events. The samples studied suggest that the fiscal and operational burdens of running a charter school necessitate affiliation with an institutional partner. However, partnering brings its own set of problems, particularly unclear authority and accountability. The study reveals that a school's decision-making authority is limited, and its relationships with teachers, parents, and community members can become complicated when issues of authority and accountability are not absolutely clear. The study concludes that when institutional partners do not involve teachers, parents, and community members in creating a vision for the school, the potential for tension among the various stakeholders remains high. (WFA)