In 2003, Martín Insaurralde was elected as a councillor in the municipal council of Lomas de Zamora, under the electoral list led by Jorge Rossi as mayor.

[1][5] On 27 October 2009, Rossi resigned his post for personal reasons, and Insaurralde replaced him as a caretaker mayor,[6] as a consequence of his being the top of the electoral list, and so the first in the line of succession.

[8][9] Insaurralde also won the primary elections in August 2011 with a large margin, obtaining 62.73% of the vote, against 10.2% for the nearest candidate from the Popular Union.

[10] Insaurralde focused on infrastructure during his first term, calling it a "revolution of works", and describing the resultant costs as "not a spend, [but] an investment".

[18][5] Days later, on 26 June, the list he headed received support from the mayors of 78 municipalities of Buenos Aires,[19][20] and from the governor of the province, Daniel Scioli.

[26] Insaurralde resigned his post as a member of the Chamber of Deputies to return as a candidate for mayor of Lomas de Zamora in the 2015 Argentine general election.

[33] As part of this programme, nine new recycling centres were built across the municipality,[34] and a scheme was set up to provide school pupils with bicycles to incentivise physical activity.

He replaced Carlos Bianco as part of a cabinet reshuffle following the governing Frente de Todos' defeat in the 2021 primary elections.