Costello, Mia

Lead-sponsored a bill proposing that the Legislative Council and the Legislative Budget and Audit Committee, the panels that run legislature business and review state spending, each seat at least one member of the minority caucus instead of one from each major party (House Bill 187).

May 6, 2026Supports Anti-Corruption

Source: akleg.gov · researched July 6, 2026

Costello voted no on the House motion to override the governor's veto of SB 183, which expanded the powers of the Legislative Budget and Audit Committee and the legislative audit division. The override succeeded over her opposition and the act was chaptered as Chapter 1, FSSLA 2025.

August 2, 2025Opposes Anti-Corruption

Source: akleg.gov · researched July 31, 2026

As a state senator Costello prime-sponsored SB 125, which placed legislative members on the board of directors of the Alaska Gasline Development Corporation; the governor vetoed the bill on July 20, 2016 and it did not become law.

July 20, 2016Supports Government Efficiency

Source: akleg.gov · researched July 31, 2026

As a state representative Costello prime-sponsored HB 32, which changed how lines of business are recorded on an Alaska business license; the bill became law as Chapter 110, SLA 2014.

July 31, 2014Supports Government Efficiency

Source: akleg.gov · researched July 31, 2026

Wrote a law letting Alaska's housing agency allow commercial uses inside apartment buildings it owns or finances, and limiting liquor licenses in those buildings (House Bill 50, Chapter 57, 2013).

June 26, 2013Supports Housing Affordability

Source: akleg.gov · researched July 31, 2026

Costello broke with most of her caucus and voted yes on the House motion to override the governor's veto of HB 57, the school funding, class size and classroom communication device bill. The override carried 46-14 and the measure became law as Chapter 5, SLA 2025.

May 20, 2025Supports Public Education Quality

Source: akleg.gov · researched July 31, 2026

Introduced a bill proposing a state tax credit for career and technical education, which the House sent to its Labor and Commerce Committee on May 7, 2025 (House Bill 219).

May 7, 2025Supports Public Education Quality

Source: akleg.gov · researched July 6, 2026

As a state senator, Costello prime-sponsored SB 200 on mandatory physical activity in schools; it became Chapter 40, SLA 2016.

July 18, 2016Supports Public Education Quality

Source: akleg.gov · researched July 6, 2026

Costello voted no on the House motion to override the governor's veto of SB 64, the omnibus elections bill covering voter registration, voting, election administration and campaign contributions; the joint session sustained the veto 38-22.

May 4, 2026Opposes Election Integrity

Source: akleg.gov · researched July 31, 2026

As a state senator, Costello prime-sponsored SB 80 on telecommunications for disabled subscribers; it became Chapter 110, SLA 2018.

September 29, 2018Supports Civil Rights

Source: akleg.gov · researched July 6, 2026

Voted against overriding the governor's veto of a bill changing how highly digital businesses are taxed on income earned in Alaska. The override failed 35-25 in a joint session on January 22, 2026, short of the 45 votes needed (Senate Bill 113).

January 22, 2026Opposes Corporate Accountability

Source: akleg.gov · researched July 31, 2026

Prime-sponsored a law letting Alaska cities charge sales tax on ride-hailing trips and require the ride-hailing company to collect and pay that tax (Senate Bill 14, Chapter 31, SLA 2018).

June 18, 2018Supports Corporate Accountability

Source: akleg.gov · researched July 6, 2026

Prime-sponsored a 2016 law creating an exemption for the offering and sale of certain small securities, letting small businesses raise money from investors under lighter state rules (Senate Bill 126, Chapter 38).

July 18, 2016Opposes Corporate Accountability

Source: akleg.gov · researched July 6, 2026

Costello prime-sponsored HJR 18 urging support for a natural gas project; the Legislature lists the resolution as transmitted to the governor on June 15, 2026.

June 15, 2026Supports Public Infrastructure

Source: akleg.gov · researched July 6, 2026

Across her Senate service Costello chaired the Senate Labor and Commerce Committee in the 29th, 30th and 32nd Legislatures and chaired Senate Transportation in the 31st; in the House she chaired the Finance subcommittees on Commerce, Community and Economic Development and on Natural Resources in the 27th and 28th Legislatures. Her official committee-membership records carry these assignments as of the date verified.

July 31, 2026

Source: akleg.gov · researched July 31, 2026

Costello prime-sponsored HB 278, titled Economic Development: Alaska-Ireland Trade Commission; the Alaska Legislature lists the bill as vetoed by the governor on June 24, 2026.

June 24, 2026

Source: akleg.gov · researched July 6, 2026

As a state senator Costello prime-sponsored SB 75 on commercial vehicle licensing requirements for Alaska drivers; the bill became law as Chapter 19, SLA 2019.

August 16, 2019

Source: akleg.gov · researched July 31, 2026

Costello served as Alaska Senate Majority Leader in the 31st Legislature, holding the post from January 15 to July 8, 2019, as recorded in the Legislative Service block of her official legislature member page.

January 15, 2019

Source: akleg.gov · researched July 31, 2026

As a state senator Costello prime-sponsored SCR 14 establishing the Decoration of Honor Award; the 30th Legislature adopted it as Legislative Resolve 23.

October 8, 2018

Source: akleg.gov · researched July 31, 2026