Revenue for the Mental Health Services Act (MHSA), also known as Proposition 63, is generated from a 1% personal income tax on income in excess of $1 million. County's are given a monthly allocation based on unreserved and unspent revenue received in the State’s Mental Health Trust Fund for the MHSA. The methodology of the distribution to each County is determined by the Department of Health Care Services and is reviewed annually.

Counties are responsible for allocating MHSA funds by component. Pursuant to Welfare and Institutions Code 5892 (a) and (b), the distribution of funds by MHSA component is as follows:

1. Innovation will receive 5% of the total funding
2. Prevention and Early Intervention (PEI) will receive 20% of the balance
3. Community and Supports Services (CSS) will receive the remaining amount.

Annually, up to 20% of the average amount of funds allocated for the past five years may be transferred from CSS to prudent reserve, Workforce, Education and Training (WET), and Capital Facilities and Technological Needs (CFTN) .