From AmeriCorps*VISTA Rules and Restrictions:
During a term of service, members live at the economic level of the people they serve. The member living allowance is at the poverty level. A member may not receive any additional monetary compensation beyond the standard allowances for services rendered as an AmeriCorps VISTA member. A member also may not accept any benefit from the sponsoring organization or the community served that relates to the AmeriCorps VISTA assignment without approval from the Corporation State Office where the AmeriCorps VISTA member is assigned. Members are expected to serve the community, not themselves.

Members remain available for service, without regard to regular working hours, at all times during the member's service, except for periods of approved leave. As a result, employment is not permitted during AmeriCorps VISTA service, and you may not be absent from the project without approval from the sponsoring organization or supervisor. With the approval of the Corporation State Office, you may be involved in personal activities and creative pursuits, as long as these activities do not interfere with your service and hours of work.