The concourse is part of a nearly $4 billion project to replace terminals C and D at the airport.
The new terminal features 37 gates across four concourses.
There's also a new Delta Sky Club with a Sky Deck.
Delta operates more than 275 peak-day departures from its LaGuardia hub and is celebrating 50 years serving the airport.
The work also includes dual taxi lanes to reduce wait times and larger gate areas.
WATCH: Delta opens new concourse at LaGuardia
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