Lower, core, and upper middle market describe progressively larger businesses. Their boundaries depend on whether a source measures annual revenue, EBITDA, or enterprise value. A company can fit one segment in a revenue-based study and another in an investor’s acquisition criteria.
This reference compares revenue and EBITDA definitions, shows where those measures diverge, and brings together published U.S. company-count estimates. It uses National Center for the Middle Market research alongside the definitions used by private equity firms, lenders, and valuation indices.
Lower, core, and upper middle market revenue ranges
The National Center for the Middle Market (NCMM) defines the U.S. middle market as businesses with $10 million to $1 billion in annual revenue. Within that universe, it places the lower middle market at $10 million–$50 million, the core middle market at $50 million–$100 million, and the upper middle market at $100 million–$1 billion.1, 2
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| Segment | Annual revenue | What the range measures |
|---|---|---|
| Lower middle market | $10 million–$50 million | The smaller revenue tier within NCMM’s middle market universe. |
| Core middle market | $50 million–$100 million | The center revenue tier; sometimes simply called the middle market in a three-part comparison. |
| Upper middle market | $100 million–$1 billion | The largest revenue tier within NCMM’s definition. |
| Overall middle market | $10 million–$1 billion | All three tiers together; not an additional category to add to them. |
Source: NCMM, April 2026. Dollar ranges are annual company revenue, not EBITDA, enterprise value, or fund size. Boundary treatment should follow the dataset being used.1
Is core middle market the same as middle market?
Core middle market names the center segment in a three-part comparison. Middle market can refer either to that center or to the full lower-to-upper range, so the accompanying definition matters. A private equity firm’s mandate may also use profitability or transaction size rather than NCMM’s revenue tiers.
Published EBITDA ranges for the lower, core, and upper middle market
EBITDA ranges vary by investment strategy. CapitalPad generally describes the lower middle market as companies with $1 million–$10 million in EBITDA. Direct lenders can use much larger ranges, as the published examples below show. These are definitions used by particular firms and research indices, rather than a shared set of market boundaries.3
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| Source and context | Published EBITDA range | How to use it |
|---|---|---|
| CapitalPad: lower middle market orientation | Generally $1 million–$10 million | A smaller-company private equity convention; CapitalPad’s typical target range is narrower. |
| Golub Capital: core middle market description | $10 million–$100 million annually | A direct-lending description. It is broader than some equity firms’ “core” segment. |
| Blue Owl: upper middle market focus | Typically $100 million or more | The firm’s description of its upper middle market lending focus in January 2025. |
| Lincoln Q2 2026 private-market sub-indices | Low: below $20 million Mid: $20 million–$50 million High: $50 million–$250 million | Defined research cohorts; Lincoln labels the high comparison “large corporate,” not a universal upper middle market boundary. |
CapitalPad compilation of published conventions. Annual or last-twelve-month EBITDA as described by each source. These definitions overlap and must not be combined into a single census or treated as equivalent to NCMM’s revenue tiers.3, 4, 5, 6
A company with $18 million of EBITDA falls within Golub’s published core range and Lincoln’s low-EBITDA research cohort. Both descriptions are consistent with their respective definitions. When screening buyers or lenders, compare the company’s actual earnings with each firm’s investment criteria.
Revenue vs. EBITDA vs. enterprise value
Revenue measures sales. EBITDA measures earnings before interest, taxes, depreciation, and amortization, subject to the adjustments being used. Enterprise value measures the value of the operating business. The buyer’s equity investment is one source of funding the transaction, alongside debt and potentially seller rollover.
Use the measure that matches the question. Revenue shows sales scale; EBITDA adds information about profitability; enterprise value describes the business’s valuation. Revenue alone cannot establish an EBITDA tier because companies have different margins.
The same revenue can produce very different EBITDA
Two hypothetical companies, each with $40 million in annual revenue. Figures are illustrative, not industry margin benchmarks.
Annual EBITDA; bars start at zero and share an $8 million scale.
CapitalPad calculation: $40 million × 6% = $2.4 million; $40 million × 20% = $8 million. Both companies fit the same NCMM revenue tier despite materially different earnings.
The equity check funds only part of the transaction when debt or seller rollover also contributes to the purchase. Available cash and transaction expenses also affect the amount required. A $5 million equity investment therefore does not establish that the business has a $5 million enterprise value.
Our lower middle market EBITDA multiples guide covers valuation separately. A size definition alone cannot establish the right purchase multiple for an individual business.
How many middle market companies are there in the United States?
NCMM’s Mid-Year 2026 Middle Market Indicator cites nearly 200,000 U.S. middle market companies, using its $10 million–$1 billion annual revenue definition. The figure is a population estimate cited in the report, rather than a new census conducted in 2026.2
How many U.S. companies are in the lower middle market?
In a March 2025 podcast, NCMM estimated that approximately 160,000 U.S. companies, or about 80% of the overall middle market, fell in its $10 million–$50 million annual revenue tier.7
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| Published estimate | Company universe | Source and vintage |
|---|---|---|
| Nearly 200,000 companies | U.S. companies with $10 million–$1 billion annual revenue | NCMM estimate cited in its Mid-Year 2026 Middle Market Indicator. |
| Approximately 160,000 companies; about 80% | Lower middle market companies with $10 million–$50 million annual revenue | NCMM podcast, March 24, 2025. The lower tier is part of the overall total, not additional to it. |
Sources: NCMM. These are rounded, revenue-based population estimates from different publications. They do not count sponsor-backed companies, businesses currently for sale, or companies within particular EBITDA bands.2, 7
The cited NCMM sources do not provide current separate counts for the core and upper tiers. A count by EBITDA would require company-level earnings data rather than revenue tiers.
For acquisition sourcing, the relevant population also depends on geography, industry, ownership, and whether a business is available for sale. The overall middle market estimate is a starting point for that work.
How company size affects a private equity acquisition
Company size helps a buyer assess the management resources, financing, and operating work a transaction may require.
Management and reporting
A smaller business may need finance leadership, better systems, or a broader management team. A larger one may have those functions but require more complex coordination across divisions.
Financing and ownership
Lenders and equity investors have different minimum sizes and concentration limits. As a company grows, its potential financing universe can change, along with its documentation and reporting needs.
Growth execution
A local expansion and a multinational integration have different requirements. The sponsor needs to match the operating plan to the company’s people, systems, and capital.
Why can an add-on be smaller than a buyer’s stated minimum?
A platform acquisition must support the buyer’s ownership plan as a standalone business. An add-on joins an existing company and may use its management, infrastructure, and financing. A buyer can therefore consider add-ons below its stated minimum for a new platform. Check which type of acquisition a published size range describes.
CapitalPad’s focus within the lower middle market
CapitalPad focuses on established, historically profitable operating businesses. Its public investor profile describes typical companies with $1 million–$7 million in EBITDA and $5 million–$30 million in enterprise value in the United States and Canada. These are CapitalPad’s typical transaction parameters, not boundaries for the entire lower middle market.8
Accredited investors participate deal by deal and evaluate the company, financing, and ownership terms before choosing an investment. The lower middle market private equity guide explains the operating and investment considerations behind that focus.
Sources and approach
CapitalPad assembled this reference from NCMM research and published descriptions used by private-market firms. NCMM revenue tiers, lender EBITDA conventions, and Lincoln index cohorts describe different populations. Company counts are attributed estimates rather than CapitalPad research or a new census. No count is inferred for EBITDA segments, and no lower/core/upper counts are manufactured from survey quotas. The margin comparison is a CapitalPad hypothetical calculation.
Referencing this guide
When citing these comparisons, credit CapitalPad’s compilation and retain the underlying source, measurement basis, and publication date. Do not convert NCMM revenue-based counts into EBITDA-based company counts.
CapitalPad. Lower vs. Core vs. Upper Middle Market: Size and Company Counts. Reviewed September 24, 2026.
Sources and references
- National Center for the Middle Market, The Role of Scale in Middle Market Decision-Making, April 1, 2026. Revenue-based lower, core, and upper tiers. Source
- National Center for the Middle Market, Mid-Year 2026 Middle Market Indicator, page 2. Nearly 200,000-company estimate and $10 million–$1 billion revenue universe; not a new census of PE targets. Source
- CapitalPad, Official Information About CapitalPad. Company founders, acquisition criteria, selected acquisitions, personal co-investment, and institutional participation terms. Source
- Golub Capital, An Income Alternative: Exploring Middle Market Direct Lending. Core middle market description of $10 million–$100 million annual EBITDA. Source
- Blue Owl Capital, Navigating the Credit Markets, January 14, 2025. Its upper middle market focus described as typically $100 million or more in EBITDA. Source
- Lincoln International, Q2 2026 Lincoln Private Market Index, August 2026. Low, mid, and high EBITDA sub-index definitions; these are index cohorts. Source
- National Center for the Middle Market, The Market That Moves America, Episode 98, March 24, 2025: How Digital Payments Are Transforming the Lower Middle Market. Approximately 160,000 lower middle market companies and 80% share; revenue-based estimate. Source
- CapitalPad, Investor Overview. Individual investor terms, eligibility, review process, reporting, target holding periods, and Matt Diggity testimonial. Source
This guide is educational and is not an offer to sell securities or personalized investment advice. Private investments are illiquid and can lose value. The applicable offering documents govern each investment.
