Kosgei comes in as the defending champion after winning in 2018 in 2:18:35 and then winning London in 2:18:20. She is joined by Betsy Saina (2:22:56) and Mexico's Madai Perez (2:22:59). Chumba won Chicago in 2015, but will only be the fourth fastest in the field as Dubai champ Getaneh Molla (2:03:34) and runner-up Herpasa Negasa (2:03:40) lead the way along with previously announced Mo Farah. USA's Amy Cragg, Chris Derrick and Brogan Austin have all withdrawn.