Traffic declined at Marylebone station from the mid-20th century, particularly after the GCML closed. By the 1980s, it was threatened with closure, but was reprieved because of commuter traffic on the London to Aylesbury Line (a remaining part of the GCML) and from . In 1993 the station found a new role as the terminus of the Chiltern Main Line. Following the privatisation of British Rail, the station was expanded with two additional platforms in 2006 and improved services to . In 2015 services began between Marylebone and via a new chord connecting the main line to the Oxford to Bicester Line and an extension to following in 2016. As of 2020, it is the only main London terminus without any electrified National Rail services.