Then, it subsequently remained in the fourth level until 2015 (only split by a one-season spell in the third division), when it achieved promotion with club legend Antonio Iriondo as manager.

On 27 May 2018, Rayo Majadahonda promoted for the first time ever to Segunda División by beating FC Cartagena with a last-minute own goal from Míchel Zabaco, with Iriondo still in charge of the first team.

[5] In the second tier, the club played its home games at Atlético Madrid's Wanda Metropolitano due to the insufficient facilities at the Estadio Cerro del Espino.

[6] As part of the conditions of playing in the fully professional second division, Rayo Majadahonda had a year to establish a Sociedad Anónima Deportiva, a form of public limited company that all its teams must be.

The initial majority shareholder in September 2019 was Alejandro Arribas, a player formed at the club who was still playing professionally for Real Oviedo at the time.