Obamacare requires companies with more than 50 employees to offer health insurance to those who work 30 hours per week or more.
The coffee shop chain already offers health insurance to part-time workers clocking 20 hours per week or more.
"Other companies have announced that they won't provide coverage for spouses; others are lobbying for the cut-off to be at 40 hours," said Starbucks CEO Howard Schultz
"But Starbucks will continue maintaining benefits for partners and won't use the new law as excuse to cut benefits or lower benefits for its workers," Schultz said.
Businesses across the country are cutting staff and reducing hours in anticipation of Obamacare, or at least threatening to do so.
Darden Restaurants saw intense backlash and a sharp drop in revenue after implementing "test strategies" including greater use of part-time workers in an effort to save money on Obamacare.
Darden has since said it would not cut full-time employees' hours in response to the healthcare law.
Other brands including Papa John's and Applebee's experienced similar drops in consumer approval after announcing anti-Obamacare policies.
Last week, United Parcel Service (UPS) told non-union employees their spouses would no longer qualify for coverage if they have access to coverage through their own jobs.
But for Starbucks, "it's not about the law," Schultz said. "It's about responsibility we have to the people who do work and who represent us."