The construction of it was planned through a public-private partnership program between the Makati City Government and a private consortium headed by Philippine Infradev Holdings.

[1] In 2015, the National Economic and Development Authority approved the construction of the Makati-Pasay-Taguig Mass Transit System Loop, which would have been a 20-kilometer-long underground railway from Bonifacio Global City to Taft Avenue.

The proponents have stated that they may divert the subway towards the Philippine National Railways Buendia station or the Mile Long property in Legazpi Village instead.

[12] In July 2019, soil testing related to the subway completed as the Philippine Infradev and Makati LGU has signed a joint venture agreement for the project[13] As of October 2019, the plan to move the terminus of the line to the Mile Long property being redeveloped by the national government along Amorsolo Street has been finalized.

[14] In a disclosure to the stock exchange, the Philippine Infradev wholly owned subsidiary, Makati City Subway Inc. (MCSI) has received the term sheet from Megaworld.

Philippine Infradev Holdings, Inc. received an Environmental Compliance Certificate (ECC) from the Department of Environment and Natural Resources (DENR) and is looking to commence works before the year 2020.

On May 14, 2021, the first of five tunnel boring machine was received by the Philippine Infradev Chairman Ren Jinhua in Shanghai, China from its manufacturer in a simple ceremony.

[22] With Makati losing ten barangays to Taguig in a territorial dispute between the two cities in 2023, the subway alignment will need to be reworked because its depot and a few stations were in the affected areas.

[23] In an interview with the Philippine Daily Inquirer, Makati mayor Abigail Binay mentioned that there have been talks with the private proponents on planning on a different transportation initiative as the subway project is no longer viable to proceed.

[24] In August 2024, Isla Lipana-PwC partner Zaldy D. Aguirre, Philippine Infradev Holdings's independent auditor reported a P44 billion impairment loss in 2023.

In the aftermath of the 2019 elections, Antonio Tiu, President of Philippine Infradev has stated that he is open to initiating and entering a similar partnership deal with Makati's neighboring cities for the expansion of the subway system.