11 Important Bills That Passed During Colorado’s 2025 Legislative Session

Late Wednesday night, the 75th Colorado General Assembly regular legislative session came to an end after an eventful and relatively productive 120 days. In all, 733 bills were introduced—up from 705 last year—and those that passed will impact issues like gun rights, immigration, energy policy, education, and voting rights.

While the session has adjourned and several bills have already been signed into law, a number of others that successfully passed through both chambers of the legislature are waiting on a final stroke of the pen from Governor Jared Polis, who has until June 6 to give the final A-OK. Polis issued several high-profile vetoes over the past few months on measures governing social media companies and the state’s open records laws.

Here’s a rundown of 11 notable pieces of legislation that passed during the regular session—and which ones we think Polis might sink before June 6. Plus, we rounded up a few buzzworthy bills that didn’t make it across the finish line.

Jump Ahead:

• Semiautomatic firearms ban
• Sale of firearms ammunition
• Nuclear energy
• Name, Image, or Likeness
• Deceptive pricing
• Banning books in school libraries
• Voting rights
• Immigrant rights
• Union collective bargaining
• Rent price-fixing
• Protections for transgender people

Semiautomatic Firearms & Rapid-Fire Devices (SB-003)

• Status: Signed by governor
• Effective Date: August 1, 2026

Gun control has long been a hot-button issue in Colorado, which has been the site of some of the deadliest mass shootings in American history. Senate Bill 3 bans the manufacture of and imposes significant hurdles to acquiring certain kinds of semiautomatic firearms with detachable magazines, including AR-15 and AK-47 rifles. This bill does not impact bolt-action rifles, which are commonly used for hunting. To purchase the semiautomatic weapons outlined in the bill, a Colorado resident has to pass a background check and complete a state-sanctioned safety course. The law also bans rapid-fire trigger devices like bump stocks.

In-state gun manufacturers who make semiautomatic rifles for the military, law enforcement, prison guards, and armored-vehicle businesses are exempt, and the legislation won’t impact guns Coloradans already own. Gun-store owners in the area have voiced concerns about the law, which they say would make a sizable chunk of their inventory illegal. Among the prime sponsors of the bill was state Senator Tom Sullivan, whose son, Alex, was killed in the Aurora theater shooting in 2012.

Requirements for Sale of Firearms Ammunition (HB-1133)

• Status: Signed by governor
• Effective Date: July 1, 2026

Though not as sweeping of a gun-control measure as Senate Bill 3, House Bill 1133 raises the minimum age to buy firearm ammunition to 21 years old. If nothing else, it aligns with a law the legislature passed in 2023 that raised the minimum age to buy a firearm in Colorado to 21. Under the current law, adults over 18 can purchase rifle and shotgun ammunition, but you must be 21 to buy handgun ammunition.

Additionally, under the recently passed law, gun and ammunition retailers will have to keep bullets in an enclosed display or behind a counter.

Adding Nuclear Energy as a Clean Energy Resource (HB-1040)

• Status: Signed by governor
• Effective Date: August 6, 2025

We may see nuclear power plants popping up around the state, thanks to this bill that redefines what qualifies as “clean energy” in Colorado. House Bill 1040 allows nuclear energy to be considered a clean energy resource. The legislation will permit nuclear energy projects to receive grants previously reserved for solar, wind, and geothermal initiatives.

It will also allow nuclear energy to count toward the state’s larger renewable energy goals. The bill states that Colorado’s estimated electricity demand is projected to double in the next five years and that nuclear energy is one way to achieve “a less expensive and a more reliable path to eliminating greenhouse gas emissions.” There are currently no operating nuclear power plants in the state. Though there have been advances in nuclear technology in recent years, environmentalists still have health and safety concerns about it, like the radioactive waste it produces.

Student Athlete Name Image or Likeness (HB-1041)

• Status: Signed by governor
• Effective Date: March 28, 2025

For the past two years, the Centennial State was home to two of the country’s most well-known—and, reportedly, well-paid—college athletes in former University of Colorado football stars Travis Hunter and Shedeur Sanders. Though both are now in the NFL, House Bill 1041 allows universities in the state to directly pay students athletes of all sports for their name, image, and likeness (NIL) rights. State law previously outlawed such an arrangement, forcing athletes to seek out payments from third parties, like NIL collectives or sponsorships. Universities like CU will soon have to share millions in revenue with athletes, due to a 2024 settlement of an antitrust lawsuit against the NCAA.

Though he signed the bill into law, Polis expressed concerns about an exception in the text that shields these athlete contracts from the Colorado Open Records Act.

Protections Against Deceptive Pricing Practices (HB-1090)

• Status: Signed by governor
• Effective Date: January 1, 2026

Anyone who has ever hired movers or signed a lease is well aware that oftentimes your total doesn’t match the cost advertised on the initial price tag. A new law, though, seeks to crack down on certain kinds of hidden fees and improve price transparency. House Bill 1090 requires businesses to disclose the total cost of the good or service, including any fees on top of the base price (shipping charges and taxes don’t have to be included).

The legislation most notably targets landlords, mandating that they inform prospective renters of additional charges like valet trash fees, credit card processing fees, and pest control fees. The measure comes after Colorado Attorney General Phil Weiser and federal regulators filed a lawsuit in January against Greystar, the largest apartment owner in the country, for intentionally misleading customers about the cost of rentals. Additionally, Polis and other Colorado lawmakers received a letter in January from a Federal Trade Commission official pressing them to adopt new laws against housing fees. Although the bill is aimed at landlords, the text says it should be “broadly interpreted to achieve its intended purposes,” so it could also be applied to restaurants, hotels, and other businesses.

Library Resource Decision Standards for Public Schools (SB-063)

• Status: Signed by governor
• Effective Date: May 1, 2025

As libraries become battlefields for broader culture wars, a new law will now offer at least some additional protection to Colorado schools over what books they keep on their shelves. Under Senate Bill 63, school districts and charter schools in the state will be required to draft policies outlining how they’ll handle challenges to books. The law states that library workers cannot be fired or punished for selecting a book or not removing it without a review. The legislation also limits those who can challenge books to parents of children in the school.

Colorado Voting Rights Act (SB-001)

• Status: Passed but not signed by governor
• Effective Date: Applies to elections after January 1, 2026.

Democrats fear that the Trump Administration may chip away at citizens’ rights to vote, so Senate Bill 1 aims to codify Coloradans’ voting rights into state law. The bill guarantees the right to bring discrimination suits at the state level, bans discrimination based on gender identity or sexual orientation, expands access to multilingual ballots, and allows eligible voters to cast ballots while in jail.

The measure passed within days of Trump signing an executive order requiring proof of citizenship to register to vote in federal elections and demanding that all ballots be received by Election Day. Opponents of the bill have argued it is in conflict with parts of Colorado’s constitution (specifically that the state isn’t allowed to regulate any aspects of a local election).

Protect Civil Rights Immigration Status (SB-276)

• Status: Passed but not signed by governor
• Effective Date: Upon governor’s signature

Immigration has been perhaps the defining issue of the early months of the second Trump Administration. Senate Bill 276 aims to bolster the civil rights of immigrants in Colorado. The bill bars local governments from sharing individuals’ personal information (including citizenship status) with federal immigration authorities and restricts immigration agents from operating in non-public areas of facilities like schools, hospitals, and libraries without a valid warrant. It also removes citizenship disclosures in application documents for state IDs and in-state tuition. Finally, SB-276 prevents another state’s military force from entering Colorado without the governor’s permission.

Worker Protection Collective Bargaining (SB-005)

• Status: Passed but not signed by governor
• Effective Date: Upon governor’s signature

One of the more contentious bills of the 2025 legislative session is Senate Bill 5. The measure would do away with a requirement in the 1943 Colorado Labor Peace Act that 75 percent of workers at a company must sign off before the union can negotiate with businesses over union security, a term used for when workers are mandated to pay fees for collective bargaining representation. This bill would make it easier for unions to require all workers—whether they’re a union member or not—to pay for bargaining representation. The legislation passed, but Polis said he plans to veto it. “I’m all for unions,” Polis said during an event hosted by the Colorado Sun, “but if dues are going to be deducted from paychecks, I think the workers deserve to have a say.”

No Pricing Coordination Between Landlords (HB-1004)

• Status: Passed but not signed by governor
• Effective Date: August 6, 2025

The cost of housing has been a significant concern to Colorado residents in recent years. House Bill 1004 aims to address some of those anxieties by attempting to restrict landlords from working with RealPage and other companies that use algorithms to set rents. Some argue the practice is a form of price fixing. Several of the state’s largest landlords (including Greystar, Camden, and Cortland) use RealPage, which Colorado and seven other states sued in January.

There’s some doubt that Polis, a Democrat with a Libertarian streak, will sign off on such a regulation.

Legal Protections for Transgender Individuals (HB-1312)

• Status: Passed but not signed by governor
• Effective Date: Most aspects would take effect upon the Governor’s signature, remaining sections would take effect October 1, 2026.

Named by supporters as the Kelly Loving Act, in honor of a trans woman killed in the 2022 Club Q shooting in Colorado Springs, House Bill 1312 increases protections for transgender residents under the Colorado Antidiscrimination Act. The measure allows county clerks to issue new marriage licenses to reflect someone’s name change and requires school districts and charter schools to allow students, regardless of their biological sex, to choose to follow any version of the dress code.

The bill controversially defines deadnaming—when someone intentionally refers to a transgender person by their birth name, not their chosen one—as a form of discrimination in places of public accommodation. The final text removed a much-debated provision that would have required the courts to consider a parent’s refusal to recognize their child’s transgender identity during custody battles. Opponents claim the bill is anti-family.

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What Bills Didn’t Pass?

Protections for Users of Social Media (SB-086)

Polis vetoed Senate Bill 86, which would have required social media companies used by Colorado residents to remove flagged accounts selling guns or drugs, as well as accounts engaged in sex trafficking or sexual exploitation of minors. In a letter explaining his decision, Polis wrote that the bill “erodes privacy, freedom, and innovation.” Though the state Senate overrode the veto, the state House laid over the vote until May 9—after the close of the legislative session. In other words, the governor’s veto stands.

Modifications to Colorado Open Records Act (SB-077)

Polis also vetoed Senate Bill 77, which would have tweaked the state’s open records laws to allow journalists to have public records requests fulfilled faster than members of the general public. The state Senate did not attempt to override the veto.

Housing Developments on Faith and Educational Land (HB-1169)

House Bill 1169 would have overridden local zoning laws to allow churches and schools to build housing on their land was defeated in the Senate. Although the bill passed the House and had the support of Polis and church leaders in the Denver area—the latter of whom believed building housing on their land for those in need would fulfill their charitable mission—it was met with resistance from local leaders, who believed it was infringing on their own efforts to build more housing.