[2][3] The second phase, composed of a three-station extension towards the main square of Quilicura, which was inaugurated on September 25, 2023 with a total project cost of US$378 million.

Criticism of this delay led finally to the announcement of a new Line 3 construction project by the Chilean government on October 5, 2010.

This will provide access to the hospital itself, to Eulogio Sánchez Airport (better known as Tobalaba Airfield), and to the commune of La Reina, and close to Peñalolén.

Three more stations are scheduled to be open in 2023,[11] in the commune of Quilicura on the north; however, the expansion to Hospital Militar in La Reina was again dismissed.

On January 22, the president Piñera announced that the Hospital Militar station will be constructed after the Lines 7, 8 and 9, are completed in 2028.