Delta Air Lines has incorporated 163 Boeing 737-900ERs into its fleet, with 33 of these aircraft previously operated by Lion Air. Due to the urgency in integrating these planes, Delta did not retrofit them immediately. As a result, these planes lack inflight entertainment and WiFi connectivity, unlike the rest of Delta's fleet. The aircraft also feature only 12 first-class seats compared to Delta's standard layout of 20.
The first of these planes joined Delta's fleet in December 2022, and retrofitting efforts have been gradual. The airline initially ordered the 737-900ER from Boeing in 2011 as part of a strategy to replace older models like the Boeing 757 and Airbus A320s. The new aircraft offered improved fuel efficiency and were among the first in Delta’s fleet to feature the Boeing Sky Interior.
Delta began receiving its initial batch of -900ERs in March 2013, with several deliveries following throughout that year. By June 2019, an additional order for 20 more planes was completed. In July 2021, Delta announced acquiring used Airbus A350s and additional 737-900ERs due to an unexpected recovery from the COVID-19 pandemic.