The bargaining sessions scheduled for late April are meant to set a framework for union contracts around the country.
Both sides said they had reached a breakthrough after two years of organizing and bargaining battles.
The union Workers United has organized roughly 400 stores, but is locked in a bitter bargaining fight with the coffee chain.
Union stores are excluded from the company's North America Barista Championship. The union calls it part of a broader pattern of retaliation.
The request for an investigation could test how aggressively the Biden administration will push for employers to reveal their spending against unions.
Unionized workers at Amazon, Starbucks, Trader Joe’s and REI have accused their employers of refusing to bargain. “That's absolutely part of their strategy."
Judges have ruled in more than 30 cases that Starbucks violated workers' rights, and more decisions are in the pipeline.
“I feel like if you’ve got the ability to watch out for someone, that you should,” Shane Spicer said.
Starbucks just became the latest company to take its workers' union to court because of its name and imagery.