Lower middle market private equity firm
Rainier Partners
- HeadquartersSeattle, WA S6
- Websiterainierpartners.com
- Last verifiedOctober 19, 2026
At a glance
| Assets under management | $400M (as of Sep 2025) S6 |
|---|---|
| Latest fund | Rainier Partners Fund I, $300M (Feb 2023) S5 |
| EBITDA range | $5M to $25M S2 |
| Check size | $15M to $75M S2 |
| Deal types | Platform, Add-on, Minority S2 |
| Geography | United States, Canada S3 |
| Sectors | Construction Services, Distribution, Consumer & Food |
What Rainier Partners buys
Rainier Partners is a Seattle private equity firm that buys lower middle market services companies. Its four focus areas are services sold to other businesses, financial services such as benefits administration and insurance, consumer services such as gyms and retail, and industrial services such as distribution. It looks for companies with $5 million to $25 million of EBITDA and puts $15 million to $75 million of equity into each deal. Most deals are control buyouts, but it also does structured minority investments, and it will buy from founders, families and corporations selling a division, including in complex situations.
Rainier invests across the US and Canada and pays extra attention to the West. Its first fund closed at a $300 million hard cap in February 2023, and the firm reported more than $400 million of assets under management in September 2025. Recent platforms include Kleen-Tech, a national janitorial company, and WPAS, a benefit plan administrator. Smaller businesses are most likely to fit as add-ons: Kleen-Tech wants janitorial companies, SCI Flooring wants flooring installers, and Wilmar wants tool and garage equipment businesses.
Recent deals
Announced in the 24 months before October 19, 2026.
| Date | Company | Type | Sector | Source |
|---|---|---|---|---|
| Sep 2025 | Kleen-Tech ServicesNational janitorial services company founded in Denver in 1993, operating in more than 30 states under nine brands | Platform | Source | |
| Aug 2025 | EZREDNew Jersey maker of automotive lights, tool storage and hand tools, added to Wilmar; the owner and his son stay on | Add-on | Distribution | Source |
| Aug 2025 | Flooring PartnersBaltimore flooring installer, SCI Flooring's third add-on and its entry into East Coast markets | Add-on | Construction Services | Source |
| Dec 2024 | Welfare & Pension Administration Service (WPAS)Mercer Island, Washington administrator of multi-employer health and retirement plans, founded in 1953 | Platform | Source |
Portfolio by sector
From the firm's portfolio page S4.
Construction Services
- SCI Flooring Current
Consumer & Food
- Omega Fitness Current
- Pet Food Express Current
Distribution
- Wilmar Corporation Current
Other
- Kleen-Tech Current
- Welfare Pension & Administration Service (WPAS) Current
Greymont’s take
How Rainier Partners fits a seller
Rainier suits the owner of a services business, often in the Western US or Canada, who wants a hands-on buyer that will fund add-on acquisitions. The firm says it usually invites founders or managers to invest next to it, and when it bought Calpine Containers in 2021 the employees kept a stake, so many sellers keep some ownership. Rainier also runs a set value creation plan it calls SUMMIT, which starts with choosing the leadership team and upgrading reporting. Expect new metrics, and possibly a new chief executive: Rainier named a new CEO at Kleen-Tech in January 2026, about four months after its deal was announced.
Rainier's only announced fund is Fund I, closed in 2023, so an owner should ask how much capital is left for add-ons and when the firm expects to sell. It is also worth asking whether current leadership will stay in charge.
Questions owners ask
What size of company does Rainier Partners look for?
Companies with $5 million to $25 million of EBITDA. Rainier puts $15 million to $75 million of equity into each deal, mostly through control buyouts, and it also does structured minority investments.
Does Rainier Partners only invest in the Pacific Northwest?
No. It invests across the United States and Canada, with extra interest in the Western US and Canada. Its current companies include businesses based in Washington, California and Michigan, and Kleen-Tech, founded in Denver, works in more than 30 states.
Do owners keep a stake after selling to Rainier?
Often. Rainier says it typically invites founders or management teams to invest alongside it, and when it bought Calpine Containers in 2021 the company's employees kept an ownership interest.
Sources
- S1Rainier Partners home page Accessed October 19, 2026
- S2Rainier Partners: About (investment criteria) Accessed October 19, 2026
- S3Rainier Partners: Referrals (investment criteria) Accessed October 19, 2026
- S4Rainier Partners: Portfolio Accessed October 19, 2026
- S5Rainier Partners Announces Closing of Inaugural Fund at $300 Million Hard Cap (February 16, 2023) Accessed October 19, 2026
- S6Rainier Partners Acquires Kleen-Tech Services (September 4, 2025) Accessed October 19, 2026
- S7Rainier Partners: News & Case Studies Accessed October 19, 2026
- S8Rainier Partners Acquires Calpine Containers (April 6, 2021) Accessed October 19, 2026
- S9Rainier Partners: SUMMIT value creation approach Accessed October 19, 2026
Compiled by Greymont Advisors from public sources, including the firm’s own website and press releases. Greymont is not affiliated with Rainier Partners. Figures are as reported on the dates shown and may have changed. Request a correction