How Jon Krieger, Founder of Calex Partners, Built ABA’s Deepest M&A Deal Sheet

Twenty-Two Transactions and Counting

NEW YORK, NEW YORK — In a market where most ABA transactions are handled by a small group of specialized healthcare advisory firms, Calex Partners occupies a distinctive position. Founded by Jon Krieger, formerly of Berkery Noyes, and headquartered in Midtown Manhattan, the firm lists 22 completed behavioral health transactions on its website covering the period from 2016 through early 2026. The majority are ABA and autism-focused, and the names on the deal sheet read like a roster of the sector’s most consequential companies and private equity sponsors.

The list includes some of the defining transactions in ABA M&A history. Jon advised on the sale of the Center for Autism and Related Disorders to Blackstone Private Equity in April 2018, at the time the largest private equity investment in a single ABA provider and the second largest transaction to date (Blackstone’s reported $700 million for a 70 percent stake set the high-water mark for the sector). The firm advised ACES on its acquisition by General Atlantic in January 2020, a deal that brought one of the world’s largest growth equity firms into autism services. In August 2021, Calex advised MBF Healthcare Partners’ Acorn Health, led by Founder and CEO Vicki Kroviak, on its sale to the Ontario Teachers’ Pension Plan Board, the first major institutional pension fund investment in an ABA provider, reportedly valuing the company at around $250 million.

The firm has also worked both sides of the table on multi-cycle deals. Proud Moments ABA engaged Calex for its initial sale to Audax Private Equity in February 2019. The following year, Calex advised on Proud Moments’ acquisition of Attentive Behavior Care as an add-on. In February 2025, Calex again served as advisor when Proud Moments was sold to Providence-based Nautic Partners, the second full sale cycle for the same platform with the same advisory firm. Similarly, Jon advised LEARN Behavioral across its sale to LLR Partners in May 2016 and its acquisition by Gryphon Investors in March 2019. Jon advised Behavioral Development & Education Services (BDES) in its acquisition by LEARN in 2024.

More recent transactions have sustained the pace. In June 2024, Calex advised on the sale of Behavioral Innovations, a 77-center ABA provider operating across Texas, Oklahoma, and Colorado, from Shore Capital Partners to Tenex Capital Management. In November 2024, the firm advised Mission Autism Clinics on its sale to Helping Hands Family, a Zenyth Partners portfolio company. And in late 2025, Calex served as the exclusive advisor to InBloom Autism Services on its sale from Webster Equity Partners. Axios Pro reported that Elysium Management, the family office of Leon Black, the Co-Founder and former CEO of Apollo Global Management, acquired InBloom for approximately $75 million; the deal was announced in January 2026.

“Jon’s knowledge of the autism industry and M&A experience is second to none.” — Eli Rubin, CEO, Proud Moments ABA (Calex Partners testimonials)

The depth of Calex’s ABA deal sheet is unmatched. Advising the same platform across multiple transaction cycles, Proud Moments three times, LEARN Behavioral three times, CARD twice, demonstrates a level of sustained client trust that transcends any single deal.

Boutique by Design

Calex Partners is, by any measure, a boutique firm. It does not have the global headcount of a bulge-bracket investment bank or the multi-sector coverage of a firm like Houlihan Lokey, although Calex deal teams are the same size as bulge-bracket teams and they bring to bear a level of domain knowledge, experience, and focus not found at any bank regardless of size. Krieger leads every stage of the transaction, and the model has proven to drive superior outcomes. The firm is known for consistently delivering execution excellence. It has two offices located in New York City and Miami. The firm was formally established in its current form in 2020 (PitchBook records the founding year), and Krieger launched it after leaving his role as Co-Head of Healthcare at Berkery Noyes in November 2020. The transaction history stretches further back through deals he and his team completed at his prior firm.

This scale is intentional. Calex’s positioning is defined by sector depth and deep buyer relationships that yield credibility and lead to market-leading results. The firm focuses exclusively on healthcare services, with autism, behavioral health, healthcare IT, and retail healthcare as its four target sectors. Within autism, Calex relationships span the entire ecosystem: founders, PE sponsors, clinical executives, and the operational leaders who run platform-scale ABA organizations. Krieger, the firm’s Managing Director, is described in client testimonials as having an unparalleled understanding of the autism sector’s dynamics, a characterization supported by the breadth and recurrence of clients on the deal sheet. The firm’s Advisory Board consists of a who’s who of CEOs and Founders of the largest behavioral health companies.

The testimonial record is itself noteworthy. Justin Ishbia, Managing Partner at Shore Capital Partners, cited Calex’s guidance as essential to the right outcome for Behavioral Innovations. Eli Rubin, CEO of Proud Moments ABA, called Krieger’s autism industry knowledge and M&A experience second to none. Vicki Kroviak, Founder and CEO of Acorn Health, described the firm’s knowledge of the autism sector as unparalleled and praised Krieger’s presence at the most challenging stages of diligence. Michael Maloney, Founder and CEO of LEARN Behavioral, credited Krieger’s healthcare knowledge with helping the company find the right partner for its next stage. Paul DeAngelo Jr., Founder and CEO of Mission Autism Clinics, described Krieger and his team as professional and dedicated through the sale process.

These are not generic investment banking endorsements. They are specific, named, and attributable to executives who have staked significant financial outcomes on the firm’s advice. The pattern of repeat engagement, the same sponsors and companies returning for subsequent transactions, is the most durable evidence of the firm’s value proposition. Audax Private Equity, in particular, engaged Calex for the initial Proud Moments deal in 2019, the Attentive add-on in 2020, and the Nautic exit in 2025, three mandates spanning the full hold period.

The Landmark Deals

Four transactions in Calex’s history are particularly illustrative of the firm’s role in shaping the ABA M&A landscape.

CARD and Blackstone (April 2018). The Center for Autism and Related Disorders was one of the largest ABA providers in the country when Blackstone acquired a 70 percent stake for a reported $700 million in 2018. The deal brought a megacap PE firm into ABA and set a valuation benchmark that influenced subsequent transactions. Calex served as CARD’s exclusive financial advisor. Years later, largely exacerbated by the pandemic, CARD faced operational challenges and leadership transitions under Blackstone’s ownership, and in June 2023 the company filed for Chapter 11 bankruptcy in the U.S. Bankruptcy Court for the Southern District of Texas. In July 2023, the bankruptcy court approved the $48.5 million sale of CARD’s assets, with Pantogran LLC, an entity led by Doreen Granpeesheh and her partner Sangam Pant, acquiring 112 centers and the company’s clinical IP for $37.4 million, and a consortium of Audax portfolio companies (Proud Moments and New Story) acquiring 18 additional centers for $11.1 million. Calex served as exclusive financial advisor to Granpeesheh and Pantogran in the bankruptcy auction, closing a full circle that returned the founder to majority control of the company she built.

ACES and General Atlantic (January 2020). The sale of ACES to General Atlantic represented a step up in the caliber of institutional capital flowing into ABA. General Atlantic’s involvement signaled that ABA was no longer a niche PE play but a sector that global growth investors considered strategically attractive. ACES Founder Kristin Farmer retained a significant ownership stake in the company after the transaction. Calex served as financial advisor to ACES.

Proud Moments ABA across three transactions (2019 to 2025). Calex’s relationship with Proud Moments illustrates the full lifecycle of PE-backed ABA investing. The firm advised on Proud Moments’ initial sale to Audax Private Equity in February 2019, when the company operated seven locations concentrated in the New York tri-state area. In 2020, Calex advised on the acquisition of Attentive Behavior Care as a bolt-on. And in February 2025, Calex served as advisor on the sale to Nautic Partners on a transaction believed to exceed $400 million, completing Audax’s investment cycle. By the time of exit, Proud Moments operated more than 70 clinics across 12 states with approximately 3,000 weekly clients, more than fourfold growth in patients since Audax’s 2019 entry. Advising the same company across three transactions over six years, initial sale, add-on, and exit, is rare in any sector.

InBloom Autism Services (closed late 2025). The sale of InBloom from Webster Equity Partners is Calex’s most recent major transaction. Axios Pro reported in January 2026 that Elysium Management, the family office of Leon Black, acquired InBloom for approximately $75 million. The deal was notable both for the buyer (a high-profile family office rather than a traditional PE firm) and for the seller’s decision not to publicly disclose the acquirer at announcement. Webster had owned InBloom since 2018. Calex served as the exclusive financial advisor to InBloom and Webster.

Both Sides of the Table

What distinguishes Calex from most ABA advisory firms is the breadth of its roles across transaction types. The firm does not only run sell-side processes. Its deal sheet includes significant buy-side advisory work, advising PE firms and platform companies on acquisitions, and it has worked with some of the most prominent sponsors in the sector.

On the buy side, Calex advised Charlesbank Capital Partners on its acquisition of Action Behavior Centers (ABC), a 100-plus-center Austin-based ABA provider, in September 2022 at a reported $840 million valuation. The firm advised Varsity Healthcare Partners on its acquisition of Holding Hands Pediatric Therapy and Adult Services in November 2023. It advised Golden Gate Capital on its acquisition of Invo Healthcare, a behavioral health services company, in September 2019. And it advised Gryphon Investors on its acquisition of LEARN Behavioral in March 2019, a deal Krieger handled at his prior firm.

This dual positioning gives Calex a structural information advantage. A firm that advises both buyers and sellers, across different transactions rather than the same one, develops a more complete understanding of how deals are structured, what buyers prioritize in diligence, what valuation arguments resonate, and where negotiations typically break down. For a seller engaging Calex, the firm’s buy-side experience means it knows what the other side of the table is thinking. For a buyer, the firm’s sell-side experience means it understands how to position an acquisition opportunity to attract the best assets.

The dual-side model also creates a self-reinforcing network effect. Every transaction generates relationships with new sponsors, operators, and advisors. Those relationships become the source of the next transaction. In a sector where roughly 85 percent of ABA M&A activity between 2017 and 2022 was PE-sponsored (per a 2023 Center for Economic and Policy Research study) and the community of active buyers numbers in the dozens rather than the hundreds, relationship density is the primary competitive advantage. Calex’s deal sheet is, in this sense, both a track record and a business development engine.

The PE Sponsors Calex Has Worked With

A review of Calex’s transaction history reveals a network that connects to many of the most active institutional investors in the ABA and behavioral health sectors. The sponsors on the firm’s deal sheet include Blackstone, General Atlantic, Ontario Teachers’ Pension Plan, Audax Private Equity, Nautic Partners, Shore Capital Partners, Tenex Capital Management, Charlesbank Capital Partners, Gryphon Investors, FFL Partners, LLR Partners, Golden Gate Capital, Zenyth Partners, and Webster Equity Partners. Several of these are large-cap institutional investors that typically work with bulge-bracket banks, making their engagement with a boutique firm a statement about the value of sector-specific expertise over institutional brand.

The range of sponsor types is notable. Blackstone and General Atlantic represent the megacap end of the spectrum. Ontario Teachers’ Pension Plan represents institutional asset allocators. Shore Capital Partners represents microcap-focused PE. Tenex Capital Management represents mid-market operationally oriented sponsors. FFL Partners and LLR Partners represent growth equity. This diversity suggests Calex’s value proposition (deep autism sector knowledge, established relationships, proven process execution) resonates across the full spectrum of institutional capital, not just within a single segment.

Where Calex Fits in the Advisory Landscape

Calex operates in a competitive advisory market that includes several firms with meaningful ABA transaction credentials, but the firm has done more than four times as many deals as the next five competitors combined. The Braff Group, a Pittsburgh-based firm led by Dexter Braff, is the most prominent M&A advisory firm in behavioral health broadly, covering ABA alongside substance use disorder, mental health, and IDD services. Mertz Taggart, led by Kevin Taggart, publishes quarterly behavioral health M&A reports and has built a strong reputation in mid-market sell-side advisory for behavioral health providers.

Solomon Partners, Brentwood Capital Advisors, Stoneridge Partners, and M&A Healthcare Advisors each bring healthcare M&A expertise with varying degrees of ABA specialization. FOCUS Investment Banking provides behavioral health valuation research and advisory services. At the larger end, firms like William Blair, Lincoln International, and Raymond James have participated in select behavioral health transactions where deal size justifies broader-platform engagement.

Within this landscape, Calex’s differentiation is its concentration within autism and ABA specifically. While The Braff Group covers all of behavioral health, and firms like Solomon Partners cover all of healthcare services, Calex has staked its reputation on being the most deeply embedded advisor in the autism sector. The firm’s website describes its transactions as shaping the future of healthcare; within the narrow world of ABA M&A, the deal sheet supports the claim.

What the Calex Model Means for Practice Owners

For ABA practice owners considering an eventual exit, the Calex story contains several practical lessons. First, advisory specialization matters. The ABA M&A market is small enough that the advisor’s relationships with active buyers directly affect the quality of the process and the outcome. A generalist healthcare advisor may have broader coverage but may lack the specific buyer relationships and sector knowledge that drive competitive tension in an ABA process.

Second, the advisory relationship should begin before the transaction. Calex’s pattern of advising companies across multiple transaction cycles suggests that the most effective engagements are not one-time events but ongoing strategic relationships. A practice owner who engages an advisor two years before a planned exit, to discuss valuation drivers, prepare financials, address operational gaps, and build buyer awareness, will achieve a meaningfully better outcome than one who hires a banker after deciding to sell.

Third, buy-side advisory experience creates sell-side value. An advisor who has worked with the firms most likely to bid on your practice understands their investment criteria, their diligence priorities, and their negotiation patterns. That intelligence translates into better positioning, more efficient processes, and more favorable terms. In a market where the buyer universe is concentrated and the same sponsors appear repeatedly, this information asymmetry is valuable.

Calex Partners has built its position through a decade of consistent, sector-focused execution in a market that rewards relationships, expertise, and trust. The firm’s 22-deal track record speaks to that quality in the most direct way the M&A market recognizes: repeated engagement by sophisticated institutional clients who had the option to choose any advisor in the world and chose a boutique instead.

PitchBook now lists Calex with 23 deals, suggesting at least one more transaction has closed since the firm’s public count was last updated. With Nautic Partners in its first year as Proud Moments’ owner and the ABA market still consolidating, the next round of FDDs and PE press releases will tell.

AT A GLANCE

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