California Code, Revenue and Taxation Code - RTC § 18857

(a) An individual may designate on the tax return that a contribution in excess of the personal income tax liability, if any, be made to the Mental Health Crisis Prevention Voluntary Tax Contribution Fund, which is established by Section 18857.1. That designation is to be used as a voluntary contribution on the tax return.

(b) The contributions shall be in full dollar amounts and may be made individually by each signatory on a joint return.

(c) A designation shall be made for any taxable year on the original return for that taxable year and once made is irrevocable. If payments and credits reported on the return, together with any other credits associated with the taxpayer's account, do not exceed the taxpayer's liability, the return shall be treated as though no designation has been made.

(d) The Franchise Tax Board shall revise the form of the return to include a space labeled the “Mental Health Crisis Prevention Voluntary Tax Contribution Fund” to allow for the designation permitted. The form shall also include in the instructions information that the contribution may be in the amount of one dollar ($1) or more and that the contribution shall be used to fund the Crisis Intervention Team program that trains peace officers to assist, and engage safely with, persons living with mental illness.

(e) A deduction shall be allowed under Article 6 (commencing with Section 17201) of Chapter 3 of Part 10 for any contribution made pursuant to subdivision (a).

(f) Notwithstanding any other law, a voluntary contribution designation for the Mental Health Crisis Prevention Voluntary Tax Contribution Fund shall not be added on the return until another voluntary contribution designation is removed or space is available, whichever occurs first.