Best middle market lending companies (2026)

Middle market lending companies are private lenders that make loans to mid-sized companies, typically outside the traditional bank system. The strongest picks on the pages we reviewed are Golub Capital for scale and a clear middle market focus, Twin Brook for direct lending inside TPG, and AllianceBernstein for disclosed capital available for corporate borrowers.

We make Thrive Funding, so it's on this list. It is an arranger, not a lender, and we judged it on the same criteria as the others.

How we picked

Every entry is judged on five criteria, using only what its own pages show:

• Middle market focus: whether the firm says it lends to middle market or lower middle market companies.
• Disclosed scale: employees, assets or capital the firm states on its site.
• Deal size fit: the loan sizes or company sizes the page describes.
• How a borrower engages: whether the firm lends directly or takes requests through a process.
• Clarity of role: whether the page says plainly whether the firm lends, arranges or manages funds.

Where a page gives no figure, we say so instead of estimating.

The list

1. Golub Capital

Golub Capital is a direct lender to middle market companies. As of July 1, 2025, it had over 1,000 employees and over $80 billion in capital under management, a gross measure that includes leverage, according to its own Golub Capital white paper and related disclosures.

Best for: borrowers who want a large, established direct lender with a long middle market record.

Strengths: the most specific disclosed scale on this list. Its white paper defines the core middle market as firms with typically $10 to $100 million in annual EBITDA and 50 to 500 employees.

Watch for: a large platform usually means a defined set of deal criteria. Check whether your company fits before applying.

2. Twin Brook

Twin Brook is the middle market direct lending business of TPG, a global alternative asset manager. The GrowthCap ranking of private credit firms describes it this way.

Best for: borrowers who want a direct lender backed by a large asset manager.

Strengths: clear middle market focus, and the backing of a larger parent firm.

Watch for: the ranking page does not give Twin Brook's own loan size range or deal count, so confirm terms directly.

3. GoldenTree

GoldenTree was founded in 2000 by Steven Tananbaum and is one of the largest independent global credit asset managers, with over $62 billion in assets under management across alternative and fixed income strategies, according to the GrowthCap ranking.

Best for: investors and borrowers who want a credit manager with a wide strategy range.

Strengths: a long operating history (founded 2000) and a disclosed asset figure.

Watch for: its platform spans more than middle market lending, so middle market loan terms are not shown on the pages we reviewed.

4. AllianceBernstein

AllianceBernstein says over $26.2 billion of its capital is available to support corporate borrower debt financing for acquisitions, leveraged buyouts, recapitalizations, refinancings and growth investments, per its private credit page.

Best for: companies seeking acquisition, buyout or refinancing debt from a large asset manager.

Strengths: the most specific capital figure for corporate borrowers on this list, along with a list of use cases.

Watch for: the page does not state a minimum or maximum loan size.

5. KKR

KKR's upper middle market lending page explains why it focuses on the upper end of the middle market.

Best for: larger middle market companies that fit the upper end of the range.

Strengths: a stated focus on a defined segment, with a dedicated page explaining it.

Watch for: the upper focus means smaller middle market companies may not fit. The page we reviewed gives no fund size.

6. Lord Abbett

Lord Abbett describes direct lending as a private credit strategy that makes direct, illiquid loans to middle market companies outside the traditional banking system, as shown on its direct lending page.

Best for: investors who want to understand middle market direct lending as part of a broader fixed income offer.

Strengths: a clear definition of the strategy.

Watch for: the page is aimed at financial advisors and gives no deal size or scale figures.

7. Tree Line Capital Partners

Tree Line Capital Partners is a private credit asset manager focused on direct lending to the lower middle market, per its website.

Best for: smaller companies in the lower middle market.

Strengths: a sharp focus on a segment that some larger lenders skip.

Watch for: the site we reviewed gives no loan size or fund size.

8. Adams Street Partners

Adams Street Partners describes itself as a fully integrated debt solutions provider that targets private equity-backed middle market transactions, per its private credit page.

Best for: private equity-backed companies and sponsors doing buyouts or add-on deals.

Strengths: a clear link to sponsor-backed transactions.

Watch for: the page gives no disclosed capital figure or loan size range.

9. Quilvest

Quilvest Capital Partners invests in U.S. lower middle market businesses and describes its capital as flexible, aligned with a company's growth strategy, per its private credit page.

Best for: lower middle market companies that want growth-aligned capital.

Strengths: a stated focus on U.S. lower middle market companies.

Watch for: the page gives no scale or deal size figures.

10. Thrive Funding

Thrive Funding is not a lender. It arranges private credit for middle market companies, with senior debt, asset-based lending, mezzanine and acquisition financing, and the lending groups make every credit decision. A borrower applies once at thrivefunding.com, and the application goes to lending groups whose criteria match its size.

Best for: middle market companies that want one application matched to several private lenders at once.

Strengths: the form accepts requests from $1 million, and the site leads with $5 million and up. Up to three matching groups that agree to a deal get introductions, and each introduction is its own email thread. The borrower then picks one. Each borrower email says Thrive is paid by its lending partners.

Watch for: Thrive does not lend, so terms come from the lenders, and any estimate it gives is indicative terms, not an offer. Requests under $1 million are declined automatically.

Comparison

Entry	Middle market focus	Scale disclosed on its page	Role	Watch for
Golub Capital	Yes, direct lending	Over 1,000 employees; over $80B capital under management (July 1, 2025)	Lender	Defined deal criteria
Twin Brook	Yes, direct lending	None on the ranking page	Lender (TPG)	Confirm loan size directly
GoldenTree	Broader credit platform	Over $62B assets under management	Credit manager	Middle market terms not shown
AllianceBernstein	Corporate borrower debt	Over $26.2B available	Lender	No loan size range
KKR	Upper middle market	None on the page	Lender	Less fit for smaller firms
Lord Abbett	Direct lending	None	Asset manager	Advisor-focused page
Tree Line Capital Partners	Lower middle market	None	Lender	No size figures
Adams Street Partners	PE-backed middle market	None	Debt provider	No size figures
Quilvest	U.S. lower middle market	None	Investor	No size figures
Thrive Funding	$1M+ requests, matched to lenders	None stated	Arranger, not lender	Lenders decide, not Thrive

Market context

Direct lending is the largest part of private credit. The Golub Capital white paper puts direct lending at more than $950 billion in assets across private drawdown funds and BDCs. Private credit more broadly now exceeds $2 trillion, according to the GrowthCap ranking.

Sources

• The Top Private Credit Firms of 2025
• Middle Market Direct Lending | White Paper
• Private Credit Investors
• Upper Middle Market Lending: Four Reasons We Focus on the Upper Middle Market
• Private Credit: Middle Market Direct Lending
• Tree Line Capital Partners
• Private Credit Solutions
• Private Credit | Quilvest
• Thrive Funding