United States coffee giant Dunkin’ is facing a class action lawsuit alleging discrimination against people with lactose allergies or intolerances by up-charging for non-dairy milks.

Lawyers representing a group of 10 plaintiffs are accusing the company of violating the Americans with Disabilities Act, as well as state laws in California, New York, Texas, Colorado, Massachusetts and Hawaii.

In a lawsuit filed Dec. 26 in the Northern California U.S. District Court, the plaintiffs are seeking $5 million in damages. A separate class action suit filed in 2022 that bears similar allegations of ADA violations for non-dairy milk up-charges by Starbucks is still moving through a Florida U.S. District court.

Given the prominence of Starbucks and Dunkin’ in the U.S. coffee retail landscape, both cases are expected to create a ripple effect in policies and pricing related to milk pricing in coffee retail settings.

The Dunkin’ suit claims that dairy milk allergies and lactose intolerance each constitute disabilities under ADA regulations, and that Dunkin’ is discriminating against patrons by charging an extra 50 cents to $2.15 for the use of non-dairy alternatives such as soy, oat, coconut or almond milks.

“Defendant’s Surcharge is the same for all Non-Dairy Alternatives, making no distinction among the costs of the various different Non-Dairy Alternatives [sic.],” the complaint states. “In fact, Dunkin created a separate, higher-priced menu, aimed at customers who cannot ingest milk.”

The suit further claims that “there is no material difference between the price of lactose-containing milks and the price of Non-Dairy Alternatives that would support levying the Surcharge to substitute for a Non- Dairy Alternative in Dunkin drinks.”

As of this writing, Dunkin’ had not yet responded to DCN’s request for comment.

Given the increasing popularity of non-dairy milk over the past decade — particularly the steep rise in commercial oat milk usage — its pricing in coffee shops has remained a contentious topic.

Various animal rights and environmental groups have actively campaigned against upcharges for non-dairy milks, while some specialty coffee chains — including Stumptown Coffee Roasters and Blue Bottle Coffee — have made oat milk the default milk option for U.S. stores.

Starbucks, which remains a defendant in the Florida lawsuit, dropped upcharges for non-dairy milks in the UK market in 2021.