---
type: "Bill"
title: "Revise zoning laws related to ADUs"
description: "Revise zoning laws related to ADUs"
jurisdiction: "us/states/mt"
legislature: "Montana Legislature"
session: "2023"
identifier: "SB 528"
citation: "Montana SB 528 (2023)"
classification: ["bill"]
subjects: ["Housing", "Local Government (see also: City Subjects; County Subjects)", "Planning and Development", "Property", "Revenue", "Local"]
status: "enacted"
primary_sponsors: ["Greg Hertz"]
version_count: 10
action_count: 51
vote_count: 11
first_action: "2023-01-02T16:46:24+00:00"
last_action: "2023-05-18T15:44:39+00:00"
source: "openstates"
source_identifier: "ocd-bill/2c6aacb5-5e78-4535-a4d8-19cbc9f8419a"
source_url: "https://bills.legmt.gov/#/bill/20231/LC4384"
source_hash: "3e3e5afc0028838a17e370f2d4ddefc5e5794a46ddf3678bdcd4401a064d162e"
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-mt"]
---

# Montana SB 528 (2023) — Revise zoning laws related to ADUs

## Version chain

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

1. **SB0528.001.001_Amendments-in-Context_final-condensed.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13259)
2. **SB0528.001.001_Amendments-in-Context_final-full.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13256)
3. **SB0528.002.001_Amendments-in-Context_final-full.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13257)
4. **SB0528.002.002_Amendments-in-Context_final-full.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13258)
5. **SB0528.002.003_Amendments-in-Context_final-condensed.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13261)
6. **SB0528.002.003_Amendments-in-Context_final-full.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13260)
7. **SB0528_1.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13264)
8. **SB0528_2.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13263)
9. **SB0528_3.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13265)
10. **SB0528_X.pdf** (committee substitute) — [source](https://api.legmt.gov/docs/v1/documents/getContent?documentId=13262)

## Votes

- (S) 3rd Reading Passed — **32–18** (pass) · upper
- (S) Committee Executive Action--Bill Passed — **7–2** (pass) · upper
- (H) Tabled in Committee — **16–0** (pass) · lower
- (H) Taken from Table in Committee — **9–2** (pass) · lower
- (S) 2nd Reading Motion to Amend Carried — **34–15** (pass) · upper
- (S) 3rd Reading Passed as Amended by House — **48–1** (pass) · upper
- (S) 2nd Reading Passed as Amended — **31–18** (pass) · upper
- (H) Committee Executive Action--Bill Concurred as Amended — **9–7** (pass) · lower
- (H) 2nd Reading Concurred — **83–17** (pass) · lower
- (S) 2nd Reading House Amendments Concurred — **47–3** (pass) · upper
- (H) 3rd Reading Concurred — **85–14** (pass) · lower

## Sponsors

- Greg Hertz — primary (person)

## Timeline

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

- **2023-05-18T15:44:39+00:00** Chapter Number Assigned `became-law`
- **2023-05-17T16:30:00+00:00** (S) Signed by Governor `executive-signature`
- **2023-05-11T22:00:00+00:00** (S) Transmitted to Governor `executive-receipt`
- **2023-05-11T20:30:00+00:00** (H) Signed by Speaker `passage`
- **2023-05-05T19:30:00+00:00** (S) Signed by President `passage`
- **2023-05-04T20:06:45+00:00** (S) Returned from Enrolling
- **2023-05-04T16:32:00+00:00** (C) Printed - Enrolled Version Available `enrolled`
- **2023-05-02T18:40:04+00:00** (S) Sent to Enrolling
- **2023-05-01T23:58:00+00:00** (S) 3rd Reading Passed as Amended by House `passage, passage, reading-3, reading-3`
- **2023-05-01T23:15:00+00:00** (S) Scheduled for 3rd Reading `reading-3`
- **2023-05-01T20:57:00+00:00** (S) 2nd Reading House Amendments Concurred `amendment-amendment, amendment-passage, reading-2, reading-2`
- **2023-05-01T19:00:00+00:00** (S) Scheduled for 2nd Reading `reading-2`
- **2023-04-28T23:38:06+00:00** (H) Returned to Senate with Amendments
- **2023-04-28T20:03:00+00:00** (H) 3rd Reading Concurred `passage, reading-3`
- **2023-04-28T19:00:00+00:00** (H) Scheduled for 3rd Reading `reading-3`
- **2023-04-27T17:38:00+00:00** (H) 2nd Reading Concurred `reading-2, reading-2`
- **2023-04-27T16:00:00+00:00** (H) Scheduled for 2nd Reading `reading-2`
- **2023-04-24T19:59:00+00:00** (H) Committee Report--Bill Concurred as Amended
- **2023-04-24T19:41:05+00:00** (C) Printed - New Version Available
- **2023-04-21T18:00:00+00:00** (H) Committee Executive Action--Bill Concurred as Amended
- **2023-04-21T17:19:00+00:00** (H) Taken from Table in Committee
- **2023-04-20T21:00:00+00:00** (H) Tabled in Committee `amendment-deferral`
- **2023-04-13T21:00:00+00:00** (H) Hearing
- **2023-04-05T20:10:57+00:00** (H) First Reading `reading-1`
- **2023-04-05T19:24:33+00:00** (H) Referred to Committee `referral-committee`
- **2023-04-04T22:28:05+00:00** (S) Transmitted to House
- **2023-04-04T20:20:00+00:00** (S) 3rd Reading Passed `passage, reading-3`
- **2023-04-03T17:58:00+00:00** (S) 2nd Reading Passed as Amended `reading-2, reading-2`
- **2023-04-03T17:50:00+00:00** (C) Printed - New Version Available
- **2023-04-03T17:49:00+00:00** (S) 2nd Reading Motion to Amend Carried `reading-2`
- **2023-03-30T19:24:00+00:00** (S) Committee Report--Bill Passed `committee-passage`
- **2023-03-30T18:54:00+00:00** (C) Amendments Available
- **2023-03-29T21:00:00+00:00** (S) Committee Executive Action--Bill Passed `committee-passage`
- **2023-03-27T21:00:00+00:00** (S) Hearing
- **2023-03-24T14:56:17+00:00** (S) Referred to Committee `referral-committee`
- **2023-03-22T19:39:00+00:00** (S) First Reading `reading-1`
- **2023-03-22T19:10:26+00:00** (C) Introduced Bill Text Available Electronically
- **2023-03-22T18:09:11+00:00** (S) Introduced
- **2023-03-20T16:03:11+00:00** (C) Draft Ready for Delivery
- **2023-03-20T13:44:03+00:00** (C) Executive Director Final Review
- **2023-03-20T13:43:58+00:00** (C) Draft Ready for Delivery
- **2023-03-17T22:44:03+00:00** (C) Draft in Assembly
- **2023-03-17T21:40:23+00:00** (C) Executive Director Review
- **2023-03-17T20:42:10+00:00** (C) Bill Draft Text Available Electronically
- **2023-03-17T20:42:09+00:00** (C) Draft in Final Drafter Review
- **2023-03-17T15:27:47+00:00** (C) Draft in Input/Proofing
- **2023-03-17T14:45:39+00:00** (C) Draft to Drafter - Edit Review
- **2023-03-15T14:59:03+00:00** (C) Draft in Edit
- **2023-03-15T14:50:31+00:00** (C) Draft in Legal Review
- **2023-03-01T16:25:08+00:00** (C) Draft to Requester for Review
- **2023-01-02T16:46:24+00:00** (C) Draft Request Received `receipt`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/2c6aacb5-5e78-4535-a4d8-19cbc9f8419a`. Confidence: reported (aggregated from official Montana legislature records).