LAO warns California prison projections may understate Proposition 36 impact as CDCR updates models

Kathy Jefferson, deputy director of the California Department of Corrections and Rehabilitation’s Office of Research, told the Assembly Budget Subcommittee No. 6 that CDCR’s fall 2025 population projections — produced through June 30, 2025 — show expected decreases in custody and parole populations over the next five years. "We expect a net 5 year decrease of 6.5% for our institution population and a net 5 year decrease of 10.4% for the parole population between June 2025 and June 2030," Jefferson said.

The department said it revised its methodology to incorporate actual admissions data through 06/30/2025 for estimating the impact of Proposition 36, and that it now estimates an average length of stay of roughly 10 months for new admissions attributable to the measure. Jefferson also said certain enhancements tied to Prop 36 cases appear to extend sentence length in some instances by about 1,000 days on average.

Caitlin O'Neil of the Legislative Analyst's Office said the LAO withheld a budget recommendation pending May Revision updates but flagged two concerns for lawmakers. "The Proposition 36 estimates on the prison population may be slightly low," O'Neil said, noting that admissions ramped up in the latter half of the first year of implementation and that, in the first half of the fiscal year, the actual prison population ran about 1% higher than the Administration projected.

O'Neil told the committee that CDCR's June‑30 cut‑off for data meant initial projections relied on the first six months of implementation; additional months of data now show increasing admissions trends that could alter the trajectory. Department of Finance officials said they will continue monitoring the evolving methodology and examine revised numbers at the May Revision.

Why it matters: the committee is weighing budget adjustments that depend on population projections. LAO and CDCR staff both described methodological updates and committed to bringing revised estimates to the May Revision so lawmakers can assess budgetary needs and program impacts.

The hearing included questions from committee members about which Prop 36 offenses are resulting in prison admissions; CDCR said primary admissions fall under the Health and Safety code sections and specific Penal Code provisions identified by the department, and that fewer than 100 early cases involved admissions that extended length of stay via enhancements. The committee asked CDCR to provide a summary of the qualifying offenses and related data for the record.

The subcommittee took no votes and will consider updated projections and data during the May Revision process.