---
type: "Bill"
title: "Public safety."
description: "(1) Existing law, operative as of January 1, 2024, will, in a case in which the party bearing the burden of proof proffers expert testimony regarding medical causation and the party's expert is required as a condition of testifying to opine that causation exists to a reasonable medical probability, allow the party not bearing the burden of proof to offer the testimony of a contrary expert only if the expert can testify that a proffered alternative cause exists to a reasonable medical probability or that a matter cannot meet a reasonable degree of probability in the applicable field, as specified."
jurisdiction: "us/states/ca"
legislature: "California Legislature"
session: "20232024"
identifier: "SB 135"
citation: "California SB 135 (20232024)"
classification: ["bill", "appropriation"]
subjects: ["Public safety"]
status: "enacted"
primary_sponsors: ["Committee on Budget and Fiscal Review"]
version_count: 5
action_count: 20
vote_count: 3
first_action: "2023-01-18"
last_action: "2023-09-13"
source: "openstates"
source_identifier: "ocd-bill/dcd3a1b0-4036-41ba-a044-e35777ab7260"
source_url: "http://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202320240SB135"
source_hash: "6a4a28d4ee6e9136f86b5fd109e6ebaca806241f8d89d8170770518f74820ab2"
vintage: "2026-07-01"
source_snapshot: "https://data.openstates.org/daily/2026-07-01/public.pgdump"
retrieved_at: "2026-07-06"
confidence: "reported"
tags: ["legislation", "bill", "us-ca"]
---

# California SB 135 (20232024) — Public safety.

(1) Existing law, operative as of January 1, 2024, will, in a case in which the party bearing the burden of proof proffers expert testimony regarding medical causation and the party's expert is required as a condition of testifying to opine that causation exists to a reasonable medical probability, allow the party not bearing the burden of proof to offer the testimony of a contrary expert only if the expert can testify that a proffered alternative cause exists to a reasonable medical probability or that a matter cannot meet a reasonable degree of probability in the applicable field, as specified.

## Version chain

The bill's text revisions, in order — the diff chain from filing to enrollment.

1. **01/18/23 - Introduced** (filed) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240SB135&version=20230SB13599INT)
2. **08/28/23 - Amended Assembly** (committee substitute) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240SB135&version=20230SB13598AMD)
3. **09/13/23 - Chaptered** (committee substitute) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240SB135&version=20230SB13596CHP)
4. **SB135** (committee substitute) — [source](http://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202320240SB135)
5. **09/13/23 - Enrolled** (enrolled) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240SB135&version=20230SB13597ENR)

## Votes

- 3rd Reading SB135 B. & F.R. — **29–8** (pass) · upper
- Unfinished Business SB135 B. & F.R. (Skinner) Concurrence — **31–8** (pass) · upper
- SB 135 Budget and Fiscal Review Senate Third Reading By TING — **58–16** (pass) · lower

## Sponsors

- Committee on Budget and Fiscal Review — primary (person)

## Timeline

The legislative action history — every referral, reading, and vote.

- **2023-01-18** Introduced. Read first time. To Com. on RLS. for assignment. To print. `introduction, reading-1`
- **2023-01-19** From printer. May be acted upon on or after February 18.
- **2023-01-25** Referred to Com. on B. & F.R. `referral-committee`
- **2023-03-16** Withdrawn from committee. (Ayes 28. Noes 8. Page 357.)
- **2023-03-16** Ordered to second reading.
- **2023-03-20** Read second time. Ordered to third reading. `reading-1, reading-2`
- **2023-03-27** Read third time. Passed. (Ayes 29. Noes 8. Page 497.) Ordered to the Assembly. `passage, reading-1, reading-3`
- **2023-03-27** In Assembly. Read first time. Held at Desk. `reading-1`
- **2023-03-30** Referred to Com. on BUDGET. `referral-committee`
- **2023-08-28** From committee with author's amendments. Read second time and amended. Re-referred to Com. on BUDGET. `amendment-passage, committee-passage, reading-1, reading-2, referral-committee`
- **2023-09-06** Assembly Rule 96 suspended.
- **2023-09-06** Withdrawn from committee. (Ayes 61. Noes 17. Page 2953.)
- **2023-09-06** Ordered to second reading.
- **2023-09-07** Read second time. Ordered to third reading. `reading-1, reading-2`
- **2023-09-08** Read third time. Passed. (Ayes 58. Noes 16. Page 3102.) Ordered to the Senate. `passage, reading-1, reading-3`
- **2023-09-08** In Senate. Concurrence in Assembly amendments pending.
- **2023-09-11** Assembly amendments concurred in. (Ayes 31. Noes 8. Page 2569.) Ordered to engrossing and enrolling. `amendment-passage, committee-passage-favorable`
- **2023-09-12** Enrolled and presented to the Governor at 11:30 a.m.
- **2023-09-13** Approved by the Governor. `executive-signature`
- **2023-09-13** Chaptered by Secretary of State. Chapter 190, Statutes of 2023. `became-law`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/dcd3a1b0-4036-41ba-a044-e35777ab7260`. Confidence: reported (aggregated from official California legislature records).