2026 HSR Threshold Update: What Changed

If your deal closes on or after February 17, 2026, the HSR filing floor is now $133.9 million. That one change can mean a deal that needed a filing in 2025 does not need one in 2026.

Here’s the short version:

• Minimum size-of-transaction: $133.9 million
• Size-of-person test: $26.8 million and $267.8 million
• Any-size threshold: $535.5 million
• Effective date: February 17, 2026
• Main timing rule: use the threshold in effect on the closing date, not the signing date
• Main risk areas: earn-outs, rollover equity, staged closings, minority stakes, and roll-ups
• Waiting period: usually 30 days after filing
• Penalty risk: about $53,088 per day for noncompliance

If I had to boil the whole update down to three points, it would be this:

1. Some deals in the $126.4 million to $133.9 million range may now avoid filing.
2. Deals from $133.9 million to $535.5 million still need a size-of-person check.
3. Serial investments and roll-ups can cross the line even when each single check looks small.

Here’s a quick comparison of the headline numbers:

My takeaway: re-screen any unsigned or unclosed deal near these lines, and make sure your team counts total consideration, not just the sticker price. That means cash, assumed debt, earn-outs, rollover equity, and prior holdings can all change the answer.

The rest of the article walks through where buyers, founders, and investors tend to get this wrong - and what to check before close.

Antitrust Coordination and Hart-Scott-Rodino (HSR) - Series 79 Exam Prep

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2026 HSR thresholds vs. 2025: the figures that changed

All three core HSR tests went up from 2025 to 2026. For middle-market deals, that may sound minor. It isn't. If a deal sits near one of these lines, a small dollar shift can change whether you need to file and when you can close.

Minimum size-of-transaction threshold is now $133.9 million

The minimum reportable threshold moved from $126.4 million to $133.9 million. That's a $7.5 million increase.^[11] For deals in that narrow band, the effect is pretty direct: a $130 million acquisition that needed an HSR screen in 2025 is generally not reportable in 2026, assuming aggregation rules or prior holdings do not push the size-of-transaction amount above the new floor.^[2][8]

This hits lower-middle-market deals the hardest, especially in the $120 million to $140 million range. In that zone, valuation changes, rollover equity, or earn-out design can move a deal from one side of the line to the other. The 2026 threshold gives those deals a bit more room before pre-merger notice is required.

Size-of-person figures are now $26.8 million and $267.8 million

For deals priced between $133.9 million and $535.5 million, HSR reportability still turns on the size-of-person test. In 2026, one side must meet the $26.8 million threshold and the other must meet the $267.8 million threshold.^[4][3][9]

This is where smaller strategics and some funds need to slow down and check the math. A buyer with $260 million in assets passed the 2025 test but fails the 2026 version. So a $150 million acquisition that was reportable in 2025 may not require a filing in 2026 because the larger-person prong no longer works.^[3][8]

Most PE-backed platforms and larger funds will still clear both figures without much trouble. Smaller corporate buyers, though, shouldn't assume last year's answer still holds.

The $535.5 million automatic-reporting threshold, effective February 17, 2026

Above $535.5 million, the size-of-person test drops out. The deal is reportable no matter who the parties are, unless an exemption applies.^[3][7][9] That threshold was $505.8 million in 2025, so the new figure reflects a $29.7 million jump.^[11]

That change matters for deals in the $505 million to $535.5 million band. Under 2025 figures, those deals triggered automatic reporting. Under 2026 figures, they do not. Now they need a size-of-person review.

If your deal team modeled HSR risk using 2025 numbers, it's worth running the screen again before closing. Near these thresholds, structure and timing can change the answer.

How the 2026 update changes acquisition planning and deal timing

Which deals need a fresh HSR screen

Re-screen any deal that sits near the 2026 thresholds, especially transactions between $133.9 million and $535.5 million, where size-of-person now decides whether the filing is required.^[6][14] That range changes how buyers should screen deals before signing. Once a deal goes above $535.5 million, treat it as reportable unless an exemption applies.^{[2][19][21][9]}

The next issue is valuation. A deal can cross the line even when the headline price looks safe on paper.

How earn-outs, rollover equity, and staged closings affect the analysis

HSR looks at total consideration, not just the stated purchase price. If an earn-out has a fixed maximum, count that full amount. Contingent consideration can also push a deal above the $133.9 million threshold.^[17][12]

Rollover equity counts too, because the value rolled into the acquiring entity affects the total consideration. And related acquisitions may need to be grouped together, so staged closings can be treated as one transaction under HSR’s related-transaction rules.^[6][15]

A simple way to handle this is to model contingent consideration in low, base, and high cases at the LOI stage, then test it again at signing and once more before closing. Valuation changes, updated forecasts, and deal structure shifts during that stretch can move a transaction across a threshold.^[6][14][15]

That’s why HSR screening needs to happen at LOI, not after signing.

How the waiting period affects your closing calendar

Once you know the deal is reportable, timing becomes the problem. HSR usually imposes a 30-day waiting period before closing, and a Second Request can extend the process even more.^[14][15] For most deals, the post-compliance waiting period after a Second Request is another 30 days, which can turn review into a much longer process.^[20][22][23]

That can put real pressure on a transaction if the purchase agreement sets a closing date before HSR timing is built into the documents and financing schedule. Early HSR planning helps reduce delay risk and the chance of a contract default.^[6][15]

Build HSR timing into the LOI and purchase agreement before signing.

Minority investments and roll-ups: where founders get caught off guard

When a minority stake can trigger HSR

Ownership structure can matter just as much as deal size. A lot of founders assume HSR only comes into play when someone is buying control. That's not how it works.

HSR often turns on value, not just ownership percentage. If an investor acquires voting securities in a corporation, a filing can be triggered once the total value of what that investor will hold in that issuer goes above $133.9 million in 2026, even if the investor still owns less than 50%.^{[30][13][18][12]} The key point: HSR looks at the post-closing value of the full stake, not just the amount of the latest check.

LLCs and partnerships use a different HSR control test. In most cases, HSR turns on whether the investor acquires 50% or more of profits or assets.^[34][5][38] That said, governance rights still deserve a separate review, because control terms can still matter.

This comes up all the time in serial financings. Say an investor puts in $70 million for a minority stake, adds $40 million in a follow-on round, and later makes a $30 million strategic purchase. Now the combined value is $140 million, and that third deal will likely need a new HSR review.^[16][30][13]

How follow-on financings and roll-up strategies can cross 2026 thresholds

This is where serial investors and PE-backed platforms often get blindsided. Under the aggregation rule, HSR requires buyers to add prior acquisitions of the same issuer's voting securities when deciding whether a new deal is reportable.^[16][31][37]

The FTC and DOJ have described roll-up strategies, especially those used by private equity platforms, as "particularly pernicious" because many single deals are set up to stay below HSR thresholds and skip pre-merger review, even while the buyer keeps consolidating a market.^{[24][25][26][32][2]} Healthcare services, including anesthesiology and other medical specialties, have drawn a lot of enforcement attention.^[29][35][36]

New HSR form rules also require parties to disclose prior acquisitions in the same or related lines of business, which makes serial deal patterns much easier for the agencies to spot.^[26][28][33] In plain English, old deals now matter more when you review a new one.

A simple habit can save a lot of pain later: keep a running ledger of aggregate holdings by issuer, and update it before every new financing, warrant exercise, secondary purchase, or side letter. If more than one fund shares the same sponsor, those positions must be combined when testing thresholds.^[27][39] It also helps to treat staged commitments as one HSR review from day one, then use that running total in your intake process and pre-close HSR screen.

Next steps: build the 2026 thresholds into your M&A process

Update deal intake, valuation models, and pre-close checklists

When the thresholds change, your process needs to change too. Every HSR screening point should be updated as soon as the new numbers take effect. That means revising deal intake forms, approval templates, valuation models, and pre-close checklists to reflect the 2026 thresholds.^{[6][2][10][9][39]} For deals closing on or after February 17, 2026, your team should use those benchmarks instead of the 2025 figures during screening.^{[6][1][2][10][9]}

Your financial model should also do some of the heavy lifting. Build HSR reportability triggers right into the deal economics so the model flags deals as total consideration gets close to a threshold. That matters when earn-out estimates move or rollover equity gets repriced in the middle of negotiations. If the numbers shift, the model should catch it right away.

Pre-close checklists need a clear HSR decision point. At that stage, the team should:

• re-confirm current total consideration
• check whether deal changes affected reportability
• verify that the waiting period is built into the closing calendar

The standard waiting period is 30 days from substantial compliance with the filing.^[42] That timing should be on the calendar from the start, not noticed a few days before closing.

Use accurate finance data to support HSR planning

A lot of HSR problems come down to bad data. Reliable cap tables, asset data, and acquisition histories are what make cumulative-holdings screens work. Size-of-transaction calculations need a full picture of what is being acquired: cash, stock, assumed debt, earn-outs, rollover equity, and contingent consideration. Size-of-person tests depend on current figures for total assets and annual net sales. If the books are messy or the cap table is stale, the screen turns into guesswork.

This is where financial discipline makes a big difference long before close. Companies with clean, current financial reporting can run HSR screens fast and with confidence at any stage of a deal. That includes updated cap tables, current revenue and asset figures, and structured data on prior acquisitions. Companies without that setup often scramble during diligence, which slows the deal and increases the chance of a missed filing. The civil penalty for failing to comply with HSR notification requirements runs approximately $53,088 per day of violation.^[40][41]

Phoenix Strategy Group works with growth-stage companies on this exact part of the job - fractional CFO services, FP&A, data engineering, and M&A support that keeps financial data organized and deal-ready. With that base in place, a team can test HSR exposure at term sheet, at signing, and again before close without a last-minute rush for numbers.

Conclusion: key 2026 changes and what to do now

What matters most now is having a process that keeps up with the rule changes. Update your screening benchmarks now. Re-check any deal signed under 2025 thresholds that still has not closed. Track cumulative holdings for minority investments and roll-up strategies. And put the waiting period on the closing calendar from day one. The thresholds change every year, so your M&A process has to keep pace if you want to protect deal timing.

FAQs

How do I know which HSR threshold applies to my deal?

First, calculate the deal’s total value. Include cash, assumed liabilities, non-cash consideration, and any contingent payments.

Deals at $133.9 million or less are generally exempt.

If the deal is above $535.5 million, filing is required no matter how large or small the parties are.

For deals between $133.9 million and $535.5 million, the Size-of-Person test also comes into play. One party must have at least $267.8 million in assets or annual net sales, and the other must have at least $26.8 million.

What counts toward total consideration under HSR?

For HSR, total consideration means more than just the sticker price.

It includes:

• The purchase price of the shares or assets
• Assumed liabilities
• The fair market value of any non-cash consideration

It also covers contingent payments, such as earnouts, based on their present value. For voting securities deals, you also include the fair market value of securities from the same issuer that the acquiring person already holds.

And there’s one more piece that can trip people up: related transactions completed within 180 days must be aggregated under the rolling-acquisition rules.

Can follow-on investments trigger an HSR filing?

Yes. A follow-on investment can trigger an HSR filing if the total value you will hold after closing hits the updated threshold.

Here’s the key idea: you don’t look only at the new purchase. You calculate the full value of the voting securities, assets, and non-corporate interests that will be held once the deal closes.

If related transactions take place within 180 days, you also need to combine them under the rolling-acquisition rules. That combined amount is what determines whether the $133.9 million HSR threshold for 2026 has been crossed.

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