Colorado and Washington’s new UAPNA reporting requirements: What M&A dealmakers need to know about these groundbreaking laws

Colorado and Washington have enacted groundbreaking laws modeled after the Uniform Law Commission’s Uniform Antitrust Pre-Merger Notification Act (UAPNA), requiring parties to certain Hart-Scott-Rodino Act (HSR) reportable mergers and acquisitions to contemporaneously notify their state attorney general of the transaction. With the adoption of these laws, the landscape of merger and acquisition reporting is rapidly evolving as states assert greater oversight over transactions within their borders.

This represents a fundamental shift in the M&A regulatory landscape, as Colorado and Washington State are the first states to implement broad, industry-agnostic merger notification requirements that go beyond sector-specific rules. While several states currently have laws requiring parties to file premerger notifications for certain healthcare transactions, the UAPNA provides states with a model premerger notification law that is not limited to specific industries.

The legislative timeline: Washington leads, Colorado follows

Washington’s new merger control law took effect on July 27 (RCW 19.390.060), while Colorado’s law (C.R.S. § 6-4.5-10) will take effect on Aug. 6. Washington became the first state to enact the Uniform Antitrust Premerger Notification Act, with Colorado quickly following suit to become the second state with such comprehensive requirements.

Both laws are based on the Uniform Antitrust Pre-Merger Notification Act, a model statute developed by the Uniform Law Commission (ULC) in July 2024. The ULC, which drafts uniform laws that states may adopt, created the UAPNA as a model pre-merger notification law that requires parties in adopting states to contemporaneously submit a copy of their HSR filing with their state Attorney General. The UAPNA aims to streamline the merger review process for state Attorneys General by giving them access to HSR filings at the beginning of the federal review process and by facilitating information sharing among the Department of Justice, Federal Trade Commission, and state AGs.

State filing requirements comparison

Aspect	Washington	Colorado
Effective Date	July 27, 2025	August 6, 2025
Principal Place of Business Trigger	Yes	Yes
Revenue Threshold	20% of HSR threshold (~$25.28M)	20% of HSR threshold (~$25.28M)
Healthcare-Specific Trigger	Yes (providers/organizations)	No
Filing Fees	None	None
Documentary Materials Required	Only if principal place of business in state	Always required
Additional Materials Timeline	7 days upon request	7 days upon request
Penalties	Up to $10,000/day	Up to $10,000/day
Waiting Period	None	None

What dealmakers need to know

Who must report: Understanding the Nexus requirements

Washington state requirements

Washington’s Uniform Antitrust Premerger Notification Act law requires parties to an HSR-reportable transaction to share their HSR filing with the Washington Attorney General if the party has a principal place of business in Washington, had annual net sales in Washington of goods or services involved in the transaction of 20 percent or more of the current HSR filing threshold (for 2025, $25.28 million), or is a “provider” or “provider organization” active in Washington state. The healthcare provider provision is unique to Washington and reflects the state’s particular focus on healthcare transactions, which have been subject to separate notification requirements in many states.

Colorado requirements

Colorado’s Uniform Antitrust Pre-Merger Notification Act requires HSR-reportable transaction parties to submit their HSR filing to the Colorado Attorney General if the party has a principal place of business in Colorado or had annual net sales in Colorado of goods or services involved in the transaction of 20 percent or more of the current HSR filing threshold (for 2025, $25.28 million). Notably, Colorado’s law does not include the healthcare-specific trigger that Washington adopted, though Colorado already has separate healthcare transaction notification requirements in place.

What must be filed and when

Filing requirements

In both states, parties must file a copy of the HSR form with the state attorney general at the same time as they submit it to federal antitrust authorities. However, there are important technical differences in what additional materials must be included:

Colorado: Colorado requires parties who meet either of the “principal place of business” or “in-state sales” prongs to also submit “additional documentary materials” included with the HSR filing.

Washington: Washington only requires the filing of “additional documentary materials” up front if a party meets the “principal place of business” prong.

Technical filing details: Parties required to file contemporaneously with the state because their principal place of business is in the state must include a complete electronic copy of the HSR filing and documentary attachments. Parties filing with a state AG based on other thresholds may submit only the HSR form but must provide documentary attachments no later than seven days after receiving a request for such information by the attorney general.

Additional information requests

Both states preserve the right to request additional documentation beyond the initial filing. In Colorado, any party required to file under the statute must provide the “additional documentary material” within seven days of the request by the AG. In Washington, the same seven-day deadline applies when the AG makes a request, but only if a party is required to file with the state AG based on either the “sales” or “healthcare” prong.

Key differences from federal HSR requirements

No waiting period or fees

Neither state’s law imposes a waiting period that would delay closing. There are also no filing fees. This distinguishes these state requirements from the federal HSR process, which includes a 30-day waiting period (or 15 days in certain circumstances) and substantial HSR filing fees.

Significant penalties for non-compliance

Despite the absence of filing fees, the penalty structure is substantial. Each state may impose civil penalties of up to $10,000 per day for failure to file the required materials. This creates a significant financial incentive for compliance, particularly given that violations accrue daily.

Confidentiality and Information Sharing

Protection of sensitive information

Both statutes include confidentiality provisions. The filings, including all additional documents, are protected from public disclosure. Disclosure, however, may be permitted in court or administrative proceedings under appropriate protective orders.

Interstate cooperation

The laws permit the AG to share information with other state AGs, but only if the receiving state has adopted a similar law with confidentiality protections “at least as protective” as those in the Uniform Act. Each statute also requires that parties be given at least two business days of notice before any disclosure between AGs occurs.

This provision facilitates the broader goal of enhanced coordination among state enforcers while maintaining appropriate safeguards for confidential business information.

The broader trend of the UAPNA: More states on the horizon

The speedy adoption of these laws in Washington and Colorado represents just the beginning of a broader trend toward state-level merger notification requirements, which is expected to expand beyond Washington and Colorado. Currently, Hawaii, West Virginia, and the District of Columbia have active legislation under consideration that would adopt UAPNA-based frameworks. While similar bills were proposed in Nevada and Utah, these measures did not advance through their respective legislatures in the most recent session.

California’s pending legislation with unique fee structure

California’s version of the UAPNA advanced in the California State Senate on June 2, but was subsequently referred to the California Assembly Committee on Appropriations on June 24 and placed on suspense file on July 9 (held in the Senate Appropriations Committee for further review due to its fiscal impact).

Notably, California’s proposed legislation includes a unique fee structure that distinguishes it from Washington and Colorado’s no-fee approach. The California bill would give the California AG discretion to impose a $1,000 filing fee on parties that have their principal place of business in California and a $500 filing fee on parties to transactions that involve goods or services with annual net sales in the state of at least 20 percent of the HSR filing threshold. If ultimately enacted, California’s law would significantly expand the scope of state-level merger oversight given the state’s economic significance.

New York’s broader approach

New York is considering even more comprehensive legislation that goes beyond the UAPNA model. New York’s 21st Century Antitrust Act—passed by the New York State Senate on June 4 and pending approval by the State Assembly and the governor—would require “any person conducting business in the state” to concurrently submit HSR filings to the New York AG. This represents a significantly looser nexus compared to the UAPNA. The legislation would also require the New York AG to consider a transaction’s impact on labor markets and establish a process to allow affected workers and their representatives to comment on a proposed transaction.

Practical implications for dealmakers

Enhanced due diligence requirements

The new state-level requirements add another layer of complexity to M&A transactions. Deal teams must now assess not only federal HSR requirements but also potential state-level obligations based on the parties’ business operations and revenue in specific states. The state revenue thresholds will sometimes require an assessment of sales by state that could be burdensome to conduct, particularly for companies with complex distribution networks or multiple business lines.

Timeline considerations

While these state laws don’t impose waiting periods, they do require contemporaneous filing with federal authorities. This means deal teams must be prepared to submit complete HSR packages to multiple jurisdictions simultaneously, requiring enhanced coordination and preparation.

Increased scrutiny risk

The enactment of the Washington and Colorado laws, as well as the introduction of the Uniform Act in other jurisdictions, shows an increased interest among states to investigate and possibly challenge deals, and the influx of information to state attorneys general could increase the likelihood that states bring cases to block deals. These filing requirements could result in transactions being reviewed by state AGs who otherwise would not have been aware of the transaction and will allow for earlier information sharing and coordination among federal and state enforcers.

Strategic considerations for dealmakers

Update internal processes

Dealmakers should update M&A checklists to flag Colorado and Washington filing triggers and plan for submission of HSR materials to state AGs. This includes training deal teams on the new requirements and establishing processes for identifying when state-level filings are required.

Monitor legal developments

Companies should monitor developments in other states, as many states, including New York, California, Hawaii, Nevada and West Virginia are actively considering similar legislation. The regulatory landscape is evolving rapidly, and what applies in one state today may apply in many others tomorrow.

Reassess deal documentation

Companies should reassess closing conditions to account for post-closing interventions by state AGs. While these laws don’t create waiting periods, they do create new avenues for state enforcement action.

Consider penalty risks

Companies should advise clients on penalty risks of up to $10,000 per day for failure to comply. Given the significant financial exposure, compliance systems must be robust and reliable.

Conduct early state sales analysis

Given the burden of assessing state-by-state sales data, companies should begin analyzing their revenue distribution early in the deal planning process to identify potential state filing obligations.

Next steps for dealmakers

1. Update deal checklists: Incorporate state-level merger notification requirements into standard M&A due diligence checklists
2. Train teams: Ensure legal and business teams understand the new filing requirements and timing considerations
3. Develop state sales analysis capabilities: Create systems to quickly assess state-by-state revenue for the 20% threshold calculations
4. Monitor pending legislation: Establish processes to track similar legislation in other states
5. Review closing conditions: Update standard transaction agreements to account for state filing requirements and potential enforcement actions

State-specific resources

• Washington State Attorney General: Official announcement and information on filing procedures – Antitrust Division handles state merger notifications
• Colorado Attorney General: Legislative information on Colorado’s Uniform Antitrust Pre-Merger Notification Act – Contact the Colorado AG’s office for specific filing guidance
• Washington State Legislature: Full text of signed law (SB 5122)
• Colorado Legislature: Full text of signed law (SB25-126)

Looking ahead: The future of state M&A control

The enactment of comprehensive merger notification laws in Washington and Colorado marks a significant shift toward increased state involvement in merger control. As more states consider similar legislation, companies engaged in M&A activity will need to navigate an increasingly complex web of state and federal requirements.

This trend reflects broader concerns about market concentration and the perceived need for additional oversight of business combinations. State attorneys general have historically played important roles in merger enforcement, particularly for transactions affecting local markets, but these new laws provide them with earlier and more comprehensive information about pending deals. States have long been authorized to investigate mergers using their general subpoena power but have primarily focused their merger enforcement efforts on transactions that raise competitive concerns in state or local markets. Although the UAPNA does not grant state AGs any new enforcement powers, certain state AGs may implement procedures for reviewing transactions that could lead to a state AG investigating a transaction that disproportionately impacts their state or in instances where a state believes the federal antitrust agencies are not adequately enforcing the federal antitrust laws.

For practitioners and dealmakers, the message is clear: state-level merger control is no longer an afterthought but a critical component of transaction planning that requires careful attention from the earliest stages of deal development. As this regulatory framework continues to evolve, staying ahead of new requirements and maintaining robust compliance systems will be essential for successful deal execution. As additional states adopt general or industry-specific premerger notification requirements, the regulatory landscape will become increasingly complex and challenging.

The Colorado and Washington laws represent just the beginning of what appears to be a sustained expansion of state-level merger oversight. Companies would be wise to prepare for a future in which multiple state jurisdictions routinely review and potentially challenge transactions that previously faced only federal scrutiny.

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