This report focuses on the Lanterman Act, a California law that gives individuals with substantial intellectual and developmental disabilities (I/DD) the right to the services and supports they need to live in community-based settings that foster their independence and community inclusion. This report draws on caselaw, administrative opinions, and other legal sources to develop a working definition of the scope of the Lanterman Act entitlement.  It begins by defining two overarching principles that that the Act encompasses, needs-based individualization and cost effectiveness, and then proposes a doctrinal framework for resolving tensions between the two when they conflict.