McDonald's: It's not technically free, but at these prices it's still worth treating yourself. For a limited time, head to a participating location and score any small McCafe specialty drink for just $2.
Bruegger's Bagels: Although the bagel chain isn't offering any day-of freebies, pay attention to its social media channels. On September 29, you can enter a flash giveaway for a chance to win free coffee for the rest of the year.
Peet's Coffee & Tea: Stop by a participating Peet's to get 25% off all beans. Plus, you'll score a free drip coffee or tea with your bean purchase. Shopping online? Take 25% off all regular, non-subscription bean purchases via the coupon code "COFFEEDAY17." There's a limit of one per person.
Community Coffee Company: Take 30% off online purchases of $30 or more via the code "COFFEEDAY" on September 29.
Krispy Kreme: This popular doughnut chain is offering free coffee beyond National Coffee Day. Stop by a participating location from September 29 through October 1 to snag one free hot brewed coffee of any size.
Dunkin' Donuts: Stop by this sweet chain with a friend on National Coffee Day for a BOGO deal. Buy one medium or large hot coffee, and receive a medium hot coffee for free.
Wawa: Last year, you could fill up on caffeine at Wawa, which offered free coffee in any size to customers. Plus, shoppers could return all day and continue to score free cups of java.
Cumberland Farms: In 2016, customers could text a code to this chain to receive a coupon. It could then be redeemed for a free hot or iced coffee in any size.
Pilot/Flying J: Previously, shoppers could download a coupon on the company's Facebook page and pop into local stores to redeem. In return, they'd receive a free small cup of coffee, or another hot beverage of their choice.
