Colorado Shifts to Robust State-Level Antitrust Enforcement Regime

Key Legislative Changes Under the 2023 Act

On June 7, 2023, Colorado Governor Jared Polis signed the Colorado State Antitrust Act of 2023 (the “2023 Act”) into law, replacing the prior Act of 1992. The 2023 Act implements a comprehensive overhaul of Colorado’s antitrust regime, expanding both the scope of prohibited conduct and the tools available to enforcers and private plaintiffs. The most notable changes include:

• Expanded liability for facilitators: The 2023 Act makes it unlawful to “facilitate or aid and abet” antitrust violations, exposing advisory firms, investors, and other market participants to potential liability.¹
• Broader investigative powers: When investigating violations of state or federal antitrust law, the AG can subpoena information from any person with relevant knowledge, not just the alleged wrongdoers, permitting wider-ranging investigations.²
• Enhanced remedies: In actions brought by the AG, courts can now go beyond actual damages to fully compensate injured parties and prevent unjust enrichment, making Colorado an attractive jurisdiction for joint state-federal enforcement actions.³
• Indirect purchaser standing: Consumers impacted by antitrust violations can now bring antitrust claims in Colorado courts even if the consumer did not deal directly with the alleged violators, broadening the range of plaintiffs seeking redress. This is a significant departure from federal law, where the Supreme Court’s Illinois Brick decision restricts “indirect purchaser” claims by consumers who purchased affected products through intermediaries like wholesalers or retailers.⁴
• Increased penalties: Maximum per-violation penalties have quadrupled, from $250,000 to $1,000,000.⁵
• Clarified statute of limitations: The limitations period now runs from the last alleged act and is tolled during federal antitrust proceedings and for one year thereafter.⁶

Increased State Enforcement

By expanding liability, investigative authority, and available remedies, the 2023 Act equipped the AG with new tools to pursue antitrust violations more aggressively. As a result, state-level enforcement has become a central feature of Colorado’s antitrust regime, with the AG taking a leading role in high-profile investigations and litigation:

• Kroger-Albertson’s Merger: In early 2024, Colorado challenged the proposed merger between grocery stores The Kroger Co. and Albertsons Companies, Inc., invoking a presumption of illegality for mergers resulting in a post-transaction market share above 30 percent. The AG characterized the challenge as a turning point in “reversing the tide against years of pressure against antitrust enforcement.” The merger was abandoned in late 2024.
• S. Anesthesia Partners of Colorado: The AG launched an investigation into U.S. Anesthesia Partners of Colorado, Inc., a healthcare entity with private equity backing, for alleged anticompetitive conduct. The investigation culminated in a consent judgment and a $200,000 payment, with the AG highlighting concerns about private equity’s impact on competition in medicine.
• National Collegiate Athletic Association (“NCAA”): Colorado joined other states in challenging NCAA transfer rules under the Sherman Act, resulting in a consent judgment that ended restrictions on athlete transfers.
• Live Nation: In 2024, Colorado filed a complaint against Live Nation Entertainment, Inc., the owner of Ticketmaster L.L.C., alleging illegal monopolization of the live entertainment market. The matter is currently pending in federal district court in New York.
• RealPage: In 2024, Colorado joined the U.S. Department of Justice (“DOJ”) and seven other states in an antitrust lawsuit against the rental revenue management software company RealPage, Inc. for alleged price fixing. Several rental management companies using the RealPage software have entered final judgments agreeing to restrict their use of nonpublic data.
• Greystar: Relatedly, in 2025, Colorado and the Federal Trade Commission (“FTC”) filed a complaint against Greystar, a rental property manager, for alleged deceptive advertising and hidden fees. However, both Colorado and the FTC sued pursuant to federal and state consumer protection statutes, not antitrust law.
• Google: In 2020, Colorado, joined by the DOJ, 34 states and 3 US territories sued Google LLC alleging violations of Section 1 and 2 of the Sherman Act. The case is ongoing.
• Syngenta Crop Protection & Corteva: In 2024, Colorado joined the FTC and nine other states in an antitrust case against two crop protection products manufacturers, alleging they used anticompetitive loyalty discount programs. The defendants’ motion to dismiss was denied in early 2024.
• Saks & Co: In 2023, Colorado, along with nineteen states, filed an amicus brief supporting a private plaintiff’s claim that Saks & Company, a luxury clothing and retail company, conspired to suppress the wages of employees via no-hire arrangements. The Second Circuit affirmed dismissal of the case in 2025.

What’s Next?

Colorado’s legislature has signaled that competition issues remain front-of-mind. For example, in early May 2025, it passed House Bill 25-1004, which would have prohibited the sale or distribution of the same algorithmic pricing tools to any “2 or more landlords” for the purpose of setting or recommending rents or occupancy levels. Governor Polis vetoed the bill in late May, citing concerns over discouraging “companies using algorithmic pricing software . . . from doing business in Colorado” and restricting the sharing of market data, which could inadvertently lead to diminished housing supply. However, he indicated that he remained open to future legislation that included language distinguishing between collusive and non-collusive uses of competitor data.

Takeaways

Colorado’s 2023 antitrust reforms mark a decisive shift toward more aggressive, state-driven competition enforcement. By expanding liability, investigative powers, and remedies, and by pursuing high-profile enforcement actions and legislative innovation, Colorado is reshaping the antitrust landscape for both local and national market participants. As the state continues to test the boundaries of its new authority, companies and practitioners should closely monitor developments and adapt their compliance strategies as follows:

• Review and update antitrust policies: Ensure that internal policies and training materials reflect the broader scope of prohibited conduct under the 2023 Act, including the new risks associated with facilitating or aiding and abetting antitrust violations.
• Conduct regular risk assessments: Evaluate business practices, joint ventures, and third-party relationships for potential antitrust risks, especially in areas such as information sharing, pricing strategies, and collaborations with competitors.
• Enhance document retention and response protocols: Given the AG’s expanded subpoena powers, companies should be prepared to respond promptly and thoroughly to investigative requests. This includes maintaining clear records and establishing protocols for legal holds and document production.
• Monitor legislative and enforcement developments: Stay informed about ongoing and proposed legislative changes, such as those targeting algorithmic pricing tools, and track enforcement trends to anticipate areas of heightened risk.
• Engage in proactive dialogue: Consider engaging with legal counsel to review compliance programs and, where appropriate, seek guidance on specific business practices that may be impacted by the new law or enforcement priorities.

¹Colo. Rev. Stat. Ann. §§ 6-4-108).

²Id. § 6-4-111(1)(a)–(c).

³Id. § 6-4-112(4)(a)–(b).

⁴Illinois Brick Co. v. Illinois, 431 U.S. 720, 729 (1977).

⁵Colo. Rev. Stat. § 6-4-113(1).

⁶Id. §§ 6-4-119(1)(b)–(4).