Martin Luther King Jr. Day is a federal holiday, but some shipping and delivery services may still be operational. Here's what we know.

While most government functions will not be operating on Monday, most grocery stores, big box stores and restaurants will remain open. Major chain stores such as Target, Costco, Walmart, The Home Depot, Jewel-Osco and Mariano's will remain open on the holiday.

Monday, January 20, commemorates the birthday of the Rev. Martin Luther King Jr. This year, the holiday coincides with President-elect Donald Trump’s inauguration, though the majority of business closures will be for MLK Day.