Mid-Market Healthcare: Why the Thesis Only Works Here

Operator-led growth equity in healthcare holds together only inside the middle market: companies with real revenue, financed with minority equity rather than debt, and small enough that operating help still changes the outcome. José Vasquéz is co-author of this analysis. It states the band as six constraints and measures each against the definitions published by the National Center for the Middle Market and by PitchBook.

01The Published Definitions

"Mid-market" is used loosely enough that two people can agree on the phrase and disagree by an order of magnitude on the company. Two published definitions anchor the term, and they measure different things.

The National Center for the Middle Market defines the middle market by company revenue: U.S. companies with annual revenues between $10 million and $1 billion. Its survey work divides that range into three segments. In its Middle Market Indicator, the smallest firms are those with revenues of $10 million to $50 million, core firms $50 million to $100 million, and the largest $100 million to $1 billion. The same report counts nearly 200,000 U.S. middle market businesses that represent one-third of private sector GDP. Most of them are privately held, according to the Center's own summary of the segment.

PitchBook defines the middle market by transaction size rather than company revenue. In the methodology of its US PE Middle Market Report, the middle market is US-based companies acquired through buyout transactions between $25 million and $1 billion, divided into the lower middle market ($25 million to $100 million), the core middle market ($100 million to $500 million) and the upper middle market ($500 million to $1 billion). The same methodology states that minority deals are not included.

That last sentence matters more than its length suggests. The most widely cited deal-size bands for the middle market are buyout bands. A minority growth equity investment is excluded from them by construction, so a growth equity strategy cannot simply borrow PitchBook's ranges as its own. It has to translate a control-transaction yardstick into a minority one, and the translation is where the constraints appear.

02The Band as Constraints

The table below states the mid-market band for healthcare growth equity as six constraints. Each row names the published reference point, what the constraint rules out, and how it reads in healthcare specifically. Figures are market definitions and market data. None is a statement of any single firm's sizing or terms.

Read together, the six rows describe a narrow corridor. The company must be large enough to have revenue that can be underwritten, and small enough that a minority, unlevered check is a meaningful share of its capital. The instrument must stay a minority instrument, which keeps it outside the buyout bands that dominate the published data. The transaction must still pass a regulatory perimeter that, in health care, begins far below the size at which federal antitrust review starts.

03The Revenue Floor

The lower edge of the band is a revenue test, and in healthcare it is the line between two different kinds of risk. Before revenue, the dominant risk in therapeutics is whether the product will be approved at all. The Biotechnology Innovation Organization's analysis of 12,728 phase transitions across 9,704 development programs found that the overall likelihood of approval from Phase I was 7.9 percent over 2011 to 2020. A risk with that shape is underwritten by portfolio construction: many positions, each sized for a probable loss. That is the venture method, and it is correct for the risk it prices.

Growth equity prices a different risk. Cambridge Associates describes the growth equity company as one with a proven business model, meaning established products, technologies and customers; substantial organic revenue growth of more than 10 percent and ideally 20 percent per year; and positive, or soon-to-be positive, EBITDA. That definition presupposes revenue. It also presupposes that the question has moved from whether the product works to whether the company can sell, deliver, get paid and scale.

In healthcare, that transition happens at a recognizable point in each of the five sectors in the LeverVenture mandate. In Biopharma & Therapeutics it follows approval and launch. In Diagnostics & Precision Medicine and in Devices & Robotics it follows clearance or approval and the first durable coverage decisions. In Digital Health & Delivery it follows contracted revenue from payers, providers or employers. In Longevity & Neuro it follows the same commercial proof as in the other four. The NCMM floor of $10 million of revenue is a reasonable marker for the point at which a company has crossed from the first kind of risk into the second, although no single figure fits every subsector.

04The Ceiling of Control and Leverage

The upper edge of the band is set by the instrument, not by ambition. As transactions grow, the buyer universe shifts toward control buyers, and control buyouts are typically financed in part with debt. GF Data, which tracked 142 deals valued between $10 million and $500 million in the first half of 2025, reported total debt to EBITDA of 3.3x for platform buyouts, unchanged from 2023 through the first half of 2025. Leveraged control is a legitimate discipline with its own toolkit. It answers a different question from the one growth equity answers.

Price also moves with size. GF Data's report for the first half of 2025 showed average enterprise value to EBITDA multiples of 7.2x across its data set, 6.3x and 6.9x in the tiers below $25 million, and 10.0x for deals of $100 million to $250 million, and described a continuing premium for scale.

The premium has a direct consequence for an operator-led minority investor. When a company is bought in the lower or core band and grows into a larger one, the size premium is part of the return. When a company is bought already priced at the top of the band, that source of return has largely been paid away at entry, and the remaining return has to come from growth alone or from leverage, which growth equity by definition uses little of.

There is a governance ceiling as well. A minority investor's influence comes from protective provisions, board participation and the value of the operating help it provides. In a company with a few hundred employees, that help can reach the reimbursement strategy, the sales model and the quality system directly. In a company several times larger, the same help is real but marginal, and the investor's minority position gives it no means to redirect the enterprise. The constraint is not that larger companies are worse investments. It is that a minority, unlevered, operator-led instrument stops being the right tool for them. The same limits bind every minority investor, including a family office, a company that manages the wealth of one family and invests in private equity directly as well as through funds.

05The Regulatory Perimeter

Federal premerger review sets one boundary. Under Section 7A of the Clayton Act, codified at 15 U.S.C. § 18a, filing obligations turn on the aggregate voting securities and assets the acquiring person would hold as a result of the acquisition, with dollar thresholds adjusted annually. The Federal Trade Commission's annual notice set the size-of-transaction threshold at $133.9 million, effective February 17, 2026 (91 Fed. Reg. 2133). All of PitchBook's lower middle market band of $25 million to $100 million sits below that line, as does the lower part of its core band.

State law reaches further down. In California, the Office of Health Care Affordability requires a health care entity to file notice of a material change transaction at least 90 days before the closing date under Cal. Code Regs. tit. 22, § 97435. The filing thresholds include annual revenue of at least $25 million, or at least $10 million where the entity transacts with a party that meets the $25 million test, and providers in designated primary care health professional shortage areas. The regulation implements Health and Safety Code section 127507.

In Oregon, ORS 415.500 defines a material change transaction as one in which at least one party had average revenue of $25 million or more in the preceding three fiscal years and another party had average revenue of at least $10 million. ORS 415.501 requires notice to the Oregon Health Authority no less than 180 days before the transaction, and the review can end in approval, approval with conditions or disapproval. The statute reaches mergers, acquisitions, corporate affiliations and the formation of new partnerships, joint ventures and management services organizations, as the Authority prescribes by rule.

The practical reading is that the healthcare middle market is not a lightly regulated space between venture and buyout. A transaction can sit tens of millions of dollars below the federal filing threshold and still require a 90-day or 180-day state notice period. Whether a particular minority investment is a covered transaction turns on the statutory definitions and the agencies' rules, and it is analyzed deal by deal with counsel. For underwriting, the review period belongs on the timeline and in the closing conditions from the first term sheet, not after signing.

06The Operating Mandate

The constraints above define where the band is. The operating mandate explains why the thesis works inside it. A healthcare company in the NCMM lower segment usually has a product that works and revenue that proves demand, and it usually lacks some combination of reimbursement strategy, a repeatable sales motion, a quality system built to scale, and the data infrastructure to measure and report outcomes. Each of those gaps is an execution problem. An operator-led investor that has run those functions can close them, and at this size the effect of closing them shows up in the company's revenue and margin rather than in a rounding error.

Artificial intelligence is the accelerant across all five sectors of the mandate, never a sector of its own. In a company with real revenue, an AI layer that shortens a prior authorization cycle, sharpens a diagnostic workflow or reduces the cost of serving a patient compounds on an existing commercial base. In a company without revenue, the same capability has nothing yet to compound on. The target is a healthcare-driven company that may also be deep tech in its engineering, a digital platform in its delivery or clean tech in its footprint, with an AI layer that improves how it delivers care or evidence.

The return standard is ROI², return on investment plus impact. In healthcare the two are rarely separable at this stage: a diagnostic that reaches more patients, a device that reaches more operating rooms, or a care model that reaches more members is both the impact and the revenue. The middle market is where that link is tight enough to underwrite, because the company is commercial and still small enough that execution decides the outcome.

07Frequently asked questions

What is the difference between mid-market and lower middle market private equity?

The answer depends on whose definition is used. The National Center for the Middle Market measures company revenue and places the middle market at $10 million to $1 billion, with a smallest segment of $10 million to $50 million. PitchBook measures buyout transaction size and places the lower middle market at $25 million to $100 million within a middle market of $25 million to $1 billion. A comparison is only meaningful when the unit, revenue or transaction value, is stated.

Does a healthcare deal below the HSR threshold avoid regulatory review?

Not necessarily. The federal size-of-transaction threshold is $133.9 million for transactions closing on or after February 17, 2026, but several states run their own health care transaction review at far lower levels. California requires notice at least 90 days before closing for entities with $25 million of annual revenue, or $10 million when the counterparty meets the $25 million test. Oregon requires notice 180 days before a transaction between parties with average revenues of $25 million and $10 million.

Why does growth equity use little or no leverage?

Growth equity provides capital to accelerate the growth of a company that already has a proven business model, rather than financing an acquisition of control. Cambridge Associates describes growth equity investments as typically minority stakes that use little if any leverage, with protection coming instead from seniority over common equity and from shareholder and governance provisions.

Nothing in this piece is investment, legal, tax or accounting advice, and nothing in it is an offer to sell or a solicitation of an offer to buy any security.