republic-os/legislation/us/states/ca/20232024/ab-1646.md

---
type: "Bill"
title: "Physicians and surgeons: postgraduate training: guest rotations."
description: "Existing law, the Medical Practice Act, establishes the Medical Board of California within the Department of Consumer Affairs and sets forth its powers and duties relating to the licensure and regulation of the practice of medicine by physicians and surgeons."
jurisdiction: "us/states/ca"
legislature: "California Legislature"
session: "20232024"
identifier: "AB 1646"
citation: "California AB 1646 (20232024)"
classification: ["bill"]
subjects: ["Physicians and surgeons", "guest rotations", "postgraduate training"]
status: "enacted"
primary_sponsors: ["Stephanie Nguyen"]
version_count: 8
action_count: 26
vote_count: 6
first_action: "2023-02-17"
last_action: "2023-09-27"
source: "openstates"
source_identifier: "ocd-bill/9d86631e-a1c1-49de-a928-58aea90ccf39"
source_url: "http://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202320240AB1646"
source_hash: "6057c274c63ed0fe07347d5e47d977b0a473d8acdb7439d04afe045d4d0e7939"
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 AB 1646 (20232024) — Physicians and surgeons: postgraduate training: guest rotations.

Existing law, the Medical Practice Act, establishes the Medical Board of California within the Department of Consumer Affairs and sets forth its powers and duties relating to the licensure and regulation of the practice of medicine by physicians and surgeons.

## Version chain

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

1. **02/17/23 - Introduced** (filed) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240AB1646&version=20230AB164699INT)
2. **03/23/23 - Amended Assembly** (committee substitute) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240AB1646&version=20230AB164698AMD)
3. **04/27/23 - Amended Assembly** (committee substitute) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240AB1646&version=20230AB164697AMD)
4. **08/30/23 - Amended Senate** (committee substitute) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240AB1646&version=20230AB164696AMD)
5. **09/08/23 - Amended Senate** (committee substitute) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240AB1646&version=20230AB164695AMD)
6. **09/27/23 - Chaptered** (committee substitute) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240AB1646&version=20230AB164693CHP)
7. **AB1646** (committee substitute) — [source](http://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202320240AB1646)
8. **09/18/23 - Enrolled** (enrolled) — [source](https://leginfo.legislature.ca.gov/faces/billPdf.xhtml?bill_id=202320240AB1646&version=20230AB164694ENR)

## Votes

- Do pass. — **12–3** (pass) · lower
- Do pass, but first be re-referred to the Committee on [Appropriations] — **9–3** (pass) · upper
- AB 1646 Stephanie Nguyen Assembly Third Reading — **61–13** (pass) · lower
- 3rd Reading AB1646 Stephanie Nguyen et By Atkins — **31–7** (pass) · upper
- AB 1646 Stephanie Nguyen Concurrence in Senate Amendments — **64–15** (pass) · lower
- Do pass as amended and be re-referred to the Committee on [Appropriations] — **13–3** (pass) · lower

## Sponsors

- Stephanie Nguyen — primary (person)
- Aguiar-Curry — principal coauthor (person)

## Timeline

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

- **2023-02-17** Read first time. To print. `reading-1`
- **2023-02-18** From printer. May be heard in committee March 20.
- **2023-03-23** Referred to Com. on B. & P. `referral-committee`
- **2023-03-23** From committee chair, with author's amendments: Amend, and re-refer to Com. on B. & P. Read second time and amended. `amendment-introduction, amendment-passage, reading-1, reading-2`
- **2023-03-27** Re-referred to Com. on B. & P. `referral-committee`
- **2023-04-26** From committee: Amend, and do pass as amended and re-refer to Com. on APPR. (Ayes 13. Noes 3.) (April 25). `amendment-introduction, amendment-passage, committee-passage, referral-committee`
- **2023-04-27** Read second time and amended. `amendment-passage, reading-1, reading-2`
- **2023-05-01** Re-referred to Com. on APPR. `referral-committee`
- **2023-05-10** From committee: Do pass. (Ayes 12. Noes 3.) (May 10). `committee-passage, committee-passage-favorable`
- **2023-05-11** Read second time. Ordered to third reading. `reading-1, reading-2`
- **2023-05-18** Read third time. Passed. Ordered to the Senate. (Ayes 61. Noes 13. Page 1593.) `passage, reading-1, reading-3`
- **2023-05-18** In Senate. Read first time. To Com. on RLS. for assignment. `reading-1`
- **2023-05-31** Referred to Com. on B., P. & E. D. `referral-committee`
- **2023-06-19** From committee: Do pass and re-refer to Com. on APPR. (Ayes 9. Noes 3.) (June 19). Re-referred to Com. on APPR. `committee-passage, committee-passage-favorable, referral-committee`
- **2023-08-14** From committee: Be ordered to second reading pursuant to Senate Rule 28.8. `committee-passage, reading-2`
- **2023-08-15** Read second time. Ordered to third reading. `reading-1, reading-2`
- **2023-08-30** Read third time and amended. Ordered to second reading. `amendment-passage, reading-1, reading-3`
- **2023-08-31** Read second time. Ordered to third reading. `reading-1, reading-2`
- **2023-09-08** Read third time and amended. Ordered to second reading. `amendment-passage, reading-1, reading-3`
- **2023-09-11** Read second time. Ordered to third reading. `reading-1, reading-2`
- **2023-09-12** Read third time. Passed. Ordered to the Assembly. (Ayes 31. Noes 7. Page 2653.). `passage, reading-1, reading-3`
- **2023-09-12** In Assembly. Concurrence in Senate amendments pending.
- **2023-09-13** Senate amendments concurred in. To Engrossing and Enrolling. (Ayes 64. Noes 15. Page 3414.). `amendment-passage, committee-passage-favorable`
- **2023-09-21** Enrolled and presented to the Governor at 3:30 p.m.
- **2023-09-27** Approved by the Governor. `executive-signature`
- **2023-09-27** Chaptered by Secretary of State - Chapter 257, 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/9d86631e-a1c1-49de-a928-58aea90ccf39`. Confidence: reported (aggregated from official California legislature records).