The line is the product of two lines, the former Line 8 from  to Nuevos Ministerios and the former Suburbano (also known as Line S) from  to , this section being named line 10 in the 1980s, and formerly operated by FEVE until the management of Line S was transferred to the Community of Madrid.
The line is formed by merging two existing lines, Line 8 connecting  to Nuevos Ministerios, and Line S (also referred to as Suburbano) linking  to , which was initially labeled as Line 10 in the 1980s and was previously managed by FEVE before being taken over by the Community of Madrid.