Democratic Rep. Kyrsten Sinema has filed nominating petitions to quality for the ballot as she prepares to seek re-election in Arizona's 9th Congressional District.
Sinema filed the petitions Wednesday at the Arizona Secretary of State's office in Phoenix.
The first-term congresswoman will face one of two Republicans considered front-runners in the party's August primary.
Former Arizona State and NFL quarterback Andrew Walter and retired U.S. Air Force pilot Wendy Rogers are vying for the GOP nomination.
Sinema said she knows her district is one of the most competitive in the country but is confident voters will support her.