River Valley is primarily funded like traditional public schools (also referred to as district schools). The funding formula for district schools includes two major components: a foundation rate, set by the State, and an above-foundation  rate. The above-foundation rate is set by city/town municipalities when they determine their budgets and the budgets of their public school system. (It is typically funded through local real estate tax revenue.) District schools receive the foundation funding from the State of Massachusetts, plus receive the above-foundation amount set by the local town governmental agency. Together, these two amounts constitute the per pupil tuition rate. The per pupil tuition rate follows the student when a child attends a public Commonwealth charter school.

Unlike district schools, charter schools do not qualify for state building assistance and will often meet their facilities costs through their operating budgets and through fundraising efforts. In addition to the per pupil funding, charter schools also receive a per pupil facility stipend (dependent annually on the State Budgeting process).

The River Valley Charter School Foundation, a 501(c)3 organization, has been established for the purpose of raising funds for the school. This work is carried out through the Development Committee of the Board of Trustees. The Development Committee holds an annual appeal as well as other fundraising efforts. The RVCS Foundation grants funds back to the school to cover costs associated with field trips, Montessori materials, music and art programming, and other educational projects.