---
type: "Bill"
title: "Relating to: admissibility of expert witness testimony."
description: "Relating to: admissibility of expert witness testimony."
jurisdiction: "us/states/wi"
legislature: "Wisconsin Legislature"
session: "2025"
identifier: "SB 459"
citation: "Wisconsin SB 459 (2025)"
classification: ["bill"]
subjects: []
status: "enacted"
primary_sponsors: ["Feyen", "Marklein", "Wanggaard", "Wimberger"]
version_count: 1
action_count: 26
vote_count: 1
first_action: "2025-10-02T05:00:00+00:00"
last_action: "2026-03-09T05:00:00+00:00"
source: "openstates"
source_identifier: "ocd-bill/ec808298-1dbd-4151-b171-7460df1f646b"
source_url: "https://docs.legis.wisconsin.gov/2025/proposals/reg/sen/bill/sb459"
source_hash: "a4a7f02754d93414a0a4da8d065a568b3bd843684ec4ed0731f98382961ef7ed"
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-wi"]
---

# Wisconsin SB 459 (2025) — Relating to: admissibility of expert witness testimony.

## Version chain

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

1. **Bill Text** (committee substitute) — [source](https://docs.legis.wisconsin.gov/document/proposaltext/2025/REG/SB459)

## Votes

- Report passage recommended by Committee on Judiciary and Public Safety, Ayes 8, Noes 0 — **8–0** (pass) · upper

## Sponsors

- Feyen — primary (person)
- Marklein — primary (person)
- Wanggaard — primary (person)
- Wimberger — primary (person)

## Timeline

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

- **2025-10-02T05:00:00+00:00** Introduced by Senators Wanggaard, Feyen, Marklein and Wimberger; cosponsored by Representatives B. Jacobson, Kreibich, Moses, Murphy, Mursau, O'Connor, Penterman, Piwowarczyk, Tittl, VanderMeer, Wittke and Duchow `introduction`
- **2025-10-02T05:00:00+00:00** Read first time and referred to Committee on Judiciary and Public Safety `reading-1, referral-committee`
- **2025-10-22T05:00:00+00:00** Public hearing held
- **2025-11-12T06:00:00+00:00** Executive action taken
- **2025-11-12T06:00:00+00:00** Report passage recommended by Committee on Judiciary and Public Safety, Ayes 8, Noes 0 `committee-passage-favorable`
- **2025-11-12T06:00:00+00:00** Available for scheduling
- **2025-11-14T06:00:00+00:00** Placed on calendar 11-18-2025 pursuant to Senate Rule 18(1)
- **2025-11-18T06:00:00+00:00** Read a second time `reading-2`
- **2025-11-18T06:00:00+00:00** Ordered to a third reading `reading-3`
- **2025-11-18T06:00:00+00:00** Rules suspended to give bill its third reading
- **2025-11-18T06:00:00+00:00** Read a third time and passed `passage, reading-3`
- **2025-11-18T06:00:00+00:00** Ordered immediately messaged
- **2025-11-19T06:00:00+00:00** Received from Senate `receipt`
- **2026-01-16T06:00:00+00:00** Read first time and referred to committee on Rules `referral-committee`
- **2026-01-20T06:00:00+00:00** Placed on calendar 1-22-2026 by Committee on Rules
- **2026-01-22T06:00:00+00:00** Rules suspended to withdraw from calendar and take up `withdrawal`
- **2026-01-22T06:00:00+00:00** Read a second time `reading-2`
- **2026-01-22T06:00:00+00:00** Ordered to a third reading `reading-3`
- **2026-01-22T06:00:00+00:00** Rules suspended
- **2026-01-22T06:00:00+00:00** Read a third time and concurred in `passage, reading-3`
- **2026-01-22T06:00:00+00:00** Ordered immediately messaged
- **2026-01-22T06:00:00+00:00** Received from Assembly concurred in `receipt`
- **2026-01-28T06:00:00+00:00** Report correctly enrolled `enrolled`
- **2026-03-05T06:00:00+00:00** Presented to the Governor on 3-5-2026 `executive-receipt`
- **2026-03-09T05:00:00+00:00** Report approved by the Governor on 3-6-2026. 2025 Wisconsin Act 92 `executive-signature`
- **2026-03-09T05:00:00+00:00** Published 3-7-2026 `became-law`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/ec808298-1dbd-4151-b171-7460df1f646b`. Confidence: reported (aggregated from official Wisconsin legislature records).