This year’s filing deadline for candidates running for the U.S. House of Representatives in Arizona was March 23, 2026.

This year has the second-fewest number of candidates running for the U.S. House since 2014. Twenty-seven candidates — 16 Democrats and 11 Republicans — are running for Arizona’s nine congressional districts. That’s three candidates per district. There were 4.2 candidates per district in 2024, 4.4 in 2022, 3.8 in 2020, 4.2 in 2018, 3.4 in 2016, and 2.8 in 2014.

In total, six primaries — four Democratic and two Republican — are contested this year. In total, there were eight contested primaries in 2024, nine in 2022, 10 in 2020, 10 in 2018, 11 in 2016, and five in 2014.

However, only one incumbent — Rep. Greg Stanton (D-4th) — is running in a contested primary. There was one incumbent in a contested primary in 2024, three in 2022, none in 2020, two in 2018, one in 2016, and none in 2014.

Two districts are open this year because the districts’ incumbents — Reps. David Schweikert (R-1st) and Andy Biggs (R-5th) — are both retiring to run for governor of Arizona. There were two open districts in 2024, one in 2022, none in 2020, two in 2018, two in 2016, and one in 2014.

One of the open districts — the 1st Congressional District — has attracted the most candidates. Seven candidates — four Democrats and three Republicans — are running for the district. The other district — the 5th Congressional District attracted the second-most candidates. Five candidates — three Democrats and two Republicans — are running for the district.

The 3rd Congressional District is guaranteed to Democrats because no Republicans will appear on the ballot. Democrats filed to run in all nine districts, meaning none are guaranteed to Republicans.

Arizona is holding U.S. House primaries on July 21, 2026.

In Arizona, primary election winners are determined via plurality vote, meaning that the candidate with the highest number of votes wins even if they did not win an outright majority of votes cast.