RepublicanIn office since Nov 2024

Mike Costlow

Missouri State Representative, District 108 since 2024. Re-elected in 2026. Next on the ballot in 2028.

Missouri State Representative, District 108

Official website Wikipedia

In office: 1 yr; Since 2024
Bills became law: 0; 50 sponsored, 2025–2026 session
Last margin: +7.5; Won 2026
Next election: 2028; Nov 7, 2028

Source: Wikidata, congress-legislators and Open States; 99chambers legislative recordsUpdated Oct 27, 2026, 1:52 PM ET

Committees

As of 2026-10.

Children and Families
Education
General Laws
Tax Reform Special
Utilities

Source: Open States committeesUpdated Oct 27, 2026, 9:43 AM ET

Legislation

2025–2026 session · 50 sponsored · 0 became law

BillIntroCmteHouseSenateLaw

HB 1730 Modifies provisions relating to firearm suppressors
BUSINESS AND COMMERCE · Failed in the Senate May 2026

HB 2658 Modifies provisions relating to electronic communications
BUSINESS AND COMMERCE · Failed in the Senate Apr 2026

HB 3351 Creates provisions for detachment from a water district for certain customers in certain circumstances
UTILITIES · Failed in the House Apr 2026

HB 1728 Modifies provisions governing city-county library boards of trustees in St. Charles County
CITIES, TOWNS, AND VILLAGES · Failed in the House Apr 2026

HB 2808 Establishes the offense of permitting, encouraging, aiding, or causing a minor to commit an offense
CHILDREN AND MINORS · Failed in the House Apr 2026

Source: Open States billsUpdated Nov 6, 2026, 4:22 PM ET

Career

Offices held, and every time Costlow was on a ballot. Filled marks are general elections won; hollow marks are primaries; an orange outline is a loss.

20242025202620272028Missouri House of Representatives, District 108

Source: 99chambers results archive (MEDSL, Klarner, state election offices)

Elections

Margin against the seat’s presidential baseline: how the seat voted for president in the same or nearest year.

Year	Race	Result	Margin	Seat	+/−
2026	Missouri House District 108	Won	R+7.5	R+21.6	−14.1
2024	Missouri House of Representatives, District 108	Won	R+27.0	—	—

Source: 99chambers results archive; 2026: civicAPI (unofficial)Updated Nov 8, 2026, 7:01 PM ET

Seats Costlow has held

Missouri House of Representatives, District 108 · since 2024

Source: 99chambers results archive

Who Costlow has run against

Stephen Scott (D) · 2026 general, won
Susan Shumway (D) · 2024 election, won

Source: 99chambers results archive; 2026: civicAPI (unofficial)

How we know Costlow

One person, matched across every source we use.

Open States ocd-person/c08a9151-fdfe-4da9-97c2-5536ed96f255
Wikidata Q133180314

Source: Identity links: Wikidata, congress-legislators, Open States, FECUpdated Oct 27, 2026, 1:52 PM ET