United Airlines (UA, Chicago O'Hare) plans to retire its B757s "as soon as possible" but will time the phase-out on the return to service of the B737 MAX, Chief Operating Officer Andrew Nocella told journalists, as reported by Reuters.

According to the ch-aviation Commercial Aviation Aircraft Data module, United Airlines currently operates fifty-four B757-200s (23.4 years old on average) and twenty-one B757-300s (17.2 years old on average). The aircraft are deployed predominantly on medium-haul domestic transcontinental routes, as well as to Hawaii from United's hubs in the western US, on secondary transatlantic routes, and on select services to the Caribbean and Latin America.

The airline planned to retire the B757s in parallel with deliveries of the new B737 MAX. However, the plan was put on hold in March when the latter type was grounded. United took deliveries of fourteen B737-9s prior to the grounding and expected to have thirty in its fleet by the end of 2019. It has a further twenty-three B737-9s and 100 B737-10s on firm order from Boeing.