[7] [8][9] Infeld originally intended to pursue graduate school at Georgetown University for the 2012–2013 academic year; however, she was not feeling fully invested in her graduate program, and with her college coach Chris Miltenberg and many training partners moving elsewhere, she decided to turn pro joining Kimbia Athletics (officially announced October 2012)[10] and move to Portland, Oregon to work under coach Jerry Schumacher at the Bowerman Track Club.

[4] After taking months off, she was beginning to progress with her career again, but in December 2014, she suffered another stress fracture of the sacrum; this time on the right side.

[19] At the 2015 Beijing World Championships on August 24, Infeld kicked hard for the bronze medal in the 10,000 m, catching a slowing Huddle at the line.

[22] On February 20, 2016, Infeld finished third in the Millrose Games women's indoor 5000 meters in 15:00.91, behind Betsy Saina and Molly Huddle.

Infeld's fellow team member, Molly Huddle, was well ahead and had one of her best performances establishing a PR of 30:13 and placing 6th.

[26] As a preparation for the 2017 USA Outdoor Track and Field Championships, Infeld participated part way through the Payton Jordan Invitational 10,000m held on May 5.

[31][32][33] In preparation for the World Championships, Infeld travelled to St. Moritz Switzerland to train and also competed in two events during her stay in Europe.

[35][36] At the 2017 World Championships in London on August 5, Infeld placed 6th where she led the USA team in a time of 31:20.45, establishing another PR in the 10,000m despite the leaders starting off with a significantly slow first 3k.

Infeld succeeded, falling just short of only one of those competitors in the local pack, Susan Krumins, who also surpassed Infeld at the end in the Huesden Belgium 5000 m. The remaining runners had a significant lead ahead of the local pack starting at 6k, which included Almaz Ayana who lapped all competitors except the three who placed behind her.

[39] Four days later, on September 10, at the 5th Avenue Mile held on the roads in New York City, Infeld placed 17th in a very competitive field in an official time of 4:31 (rounded up; 4:30.3 unofficially).

[40][41] Infeld started her 2018 season with a win at the 2018 USA Cross Country Championships in 33:18.7 (3:19.9/km), followed by Molly Seidel in 33:22.1, Stephanie Bruce in 33:34.1, her teammate Courtney Frerichs 33:55.1, Emily Durgin in 33:56.9, and Susan Tanui in 34:39.0; the six qualified for Team USA at 2018 NACAC Cross Country Championships in La Libertad, El Salvador on February 17, 2018.

On June 26, 2021, on an unusually warm day, Infeld ran the 10,000-meter final of the Olympic trials finishing in eighth place with a time of 32:19.

33:18.7[56] Beginning April 2018, and for three years thereafter (with the exception of 16 months within that time starting September/October 2018 after a protection order[57]), Infeld was stalked, which resulted in her fear, stress, and the hiding of her location.

[57] The harasser was eventually arrested and charged in June 2021 by a U.S. Attorney with felony cyberstalking and interstate violation of a protection order.