The Sarmiento Line route connecting to Once Station is one of the most heavily used and is about to change drastically. Over the next six months, trains on the Sarmiento Line will no longer run to the Once terminal, and during that period, the temporary terminus will be at Caballito Station.
This change in the Sarmiento Line’s route from Once to Caballito is due to infrastructure renovation work, but it will clearly change your daily routine, your travel times, and obviously your budget as well if you commute between the western suburbs and downtown Buenos Aires. It’s not the same to transfer from Balvanera and Plaza Once as it is from Caballito.
The change to the Sarmiento Line: What you need to know now that it no longer goes to Once
What you need to keep in mind if this news comes as a surprise is that
for the time being, the Sarmiento Line will terminate at Caballito instead of Once. You will lose direct access to Subway Line A and the transfers at Balvanera.
This temporary suspension of service is due to a tender launched by Trenes Argentinos Infraestructura to modernize the section connecting Once with Caballito
When do the works and service reductions begin?
The opening of the bid envelopes is scheduled for July 20, 2026.
The winning companies will be announced after that date. From there, an official six-month period begins to determine the final schedule for when construction will begin. In conclusion, the Once Terminal won’t stop operating right away, but once the change begins, it will last six months. You should plan ahead and start thinking about how you’ll get to school or work from Caballito.
If you commute every day from Moreno, Merlo, Morón, or Ramos Mejía, getting to Once is your direct gateway to Buenos Aires, and connecting from there to multiple subway and bus lines is very easy. Since your trip will now end at Caballito, your routine changes drastically. Plan ahead for how you’ll get around and how much you’ll have to spend to make up for the lack of access from Once.