University of Maryland medical student Sarah Britz, center, and others, rally outside the Supreme Court in Washington, Wednesday, March 4, 2015 in Washington, as the court was hearing arguments in King v. Burwell, a major test of President Barack Obama's health overhaul.

(AP Photo/Andrew Harnik)

A Texas federal judge's ruling against the Affordable Care Act on Friday could cost more than 600,000 Coloradans their coverage. 

The federal judge struck down the entire law, also known as Obamacare. The law will remain in place while the ruling is on appeal, but if it stands, the decision applies to all of the ACA's protections and regulations, and could strip health insurance coverage from 20 million Americans.

The nonpartisan Colorado Consumer Health Initiative says that includes more than 600,000 Coloradans, because the ruling would scrap both the ACA’s expansion of Medicaid and federal financial assistance for coverage in the individual marketplace.

The decision comes during a period of open enrollment for Colorado's health insurance marketplace. The Colorado Division of Insurance urges people to continue to enroll because current health insurance options will not be immediately affected.

Today is the deadline for Coloradans to sign up for coverage that starts January 1, 2019. Open enrollment for plans that start later in 2019 lasts until January 15.