Mia Costello
Alaska State Representative, District 15 since 2010. Lost re-election in 2026; leaves office in January 2027. Ran in 7 elections between 2010 and 2024, winning 6.
Alaska State Representative, District 15Born 1968Teacher
- In office
- 16 yrs
- Since 2010
- Bills became law
- 0
- 10 sponsored, 2025–2026 session
- Votes missed
- 0.0%
- Chamber median 0.6%
- With party
- 91%
- On votes splitting the parties
- Last margin
- −5.0
- Lost 2026
- Elections
- 8
- 2010–2026
Source: Wikidata, congress-legislators and Open States; 99chambers legislative recordsUpdated Oct 27, 2026, 1:52 PM ET
Committees
As of 2026-10.
- Energy Special
- Judiciary
- Rules
Source: Open States committeesUpdated Oct 27, 2026, 9:43 AM ET
Legislation
APPOINTMENTS · Vetoed Jul 2026
LEGISLATIVE COMMITTEES · Failed in committee May 2026
APPOINTMENTS · Failed in committee Apr 2026
BOARDS & COMMISSIONS · Failed in committee Apr 2026
CREDIT · Failed in committee Feb 2026
Source: Open States billsUpdated Nov 6, 2026, 4:22 PM ET
Voting record
Where Costello sits in the Alaska House of Representatives
Costello is closer to the center than 79% of the chamber's Republicans.
Closest: Will Stapp, Justin Ruffridge, Elexie Moore
Source: 99chambers roll-call scalingUpdated Nov 6, 2026, 4:44 PM ET
With Costello’s party
- Votes with the chamber's Republicans91%
- Cosponsorships of the other party's bills21%
Black tick: the average of Republicans in the Alaska House of Representatives.
Source: 99chambers legislative scores from roll calls and cosponsorships
Key votes
Votes chosen for their effect, not their side: Costello’s vote, each party’s majority, and the result. An orange vote differs from most Republicans.
| Date | Bill | Costello | Rep. majority | Dem. majority | Result |
|---|---|---|---|---|---|
| May 20, 2026 | HB 16: An Act requiring a group supporting or opposing a candidate or ballot proposition in a… | No | No | Yes | Passed 21–19 |
| May 19, 2026 | SB 24: An Act relating to tobacco, tobacco products, electronic smoking products, nicotine, and… | Yes | Yes | No | Failed 19–21 |
| May 19, 2026 | SB 174: An Act establishing the Alaska Invasive Species Council in the Department of Fish and… | Yes | No | Yes | Failed 16–23 |
| May 19, 2026 | HB 263: An Act making appropriations for the operating and loan program expenses of state… | No | No | Yes | Passed 21–19 |
| May 17, 2026 | SB 208: An Act relating to industrial hemp; relating to the sale and lease of state land for… | Yes | Yes | No | Failed 19–21 |
Source: 99chambers key votes from Congress.gov, Voteview and Open States roll calls
Career
Offices held, and every time Costello was on a ballot. Filled marks are general elections won; hollow marks are primaries; an orange outline is a loss.
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 | Alaska House of Representatives, District 15 | Lost | D+5.0 | R+2.6 | −7.6 |
| 2024 | Alaska House of Representatives, District 15 | Won | R+6.0 | R+2.6 | +3.4 |
| 2022 | Alaska State Senate, SD-H | Lost | D+3.9 | D+7.2 | +3.3 |
| 2018 | Alaska State Senate, SD-K | Won | R+14.3 | — | — |
| 2014 | Alaska State Senate, SD-K | Won | R+13.3 | — | — |
| 2014 | Alaska State Senate, SD-K (primary) | Won | — | — | — |
| 2012 | Alaska House of Representatives, District 20 | Won | R+41.5 | — | — |
| 2010 | Alaska House of Representatives, District 27 | Won | R+12.5 | — | — |
Source: 99chambers results archive; 2026: Alaska Division of Elections (unofficial)Updated Nov 8, 2026, 7:01 PM ET
Campaign money, 2025–26
- Raised
- $52.1K
- Spent
- $35.2K
Source: Alaska Public Offices Commission filings through Oct 22, 2026Updated Oct 31, 2026, 4:24 PM ET
Campaign committees
Open committees can still raise and spend money.
| Mia Costello State | Active |
Source: Alaska Public Offices Commission filings through Oct 22, 2026Updated Oct 31, 2026, 4:24 PM ET
Seats Costello has held
- Alaska House of Representatives, District 15 · since 2024
- Alaska State Senate, District K · 2014–2022
- Alaska House of Representatives, District 20 · since 2012
- Alaska House of Representatives, District 27 · since 2010
Source: 99chambers results archive
Who Costello has run against
- Denny Wells (D) · 2026 election, lost
- Matt Claman (D) · 2022 election, lost
- Sam Cason (D) · 2018 election, won
- Clare Ross (D) · 2014 election, won
- Michelle Scannell (D) · 2012 election, won
- Robert L. Buch (D) · 2010 election, won
Source: 99chambers results archive; 2026: Alaska Division of Elections (unofficial)
How we know Costello
One person, matched across every source we use.
- Open States ocd-person/aea19844-4572-4086-9462-e50ad3ff4b76
- Wikidata Q6827103
Source: Identity links: Wikidata, congress-legislators, Open States, FECUpdated Oct 27, 2026, 1:52 PM ET