Marcum LLP
Marcum LLP is a wind-down shell left after CBIZ bought its accounting practice in 2024.
On the record
Checkpoint: Motions live in Lateral Investment Management v. Marcum litigation
The call
Marcum LLP no longer operates as an independent firm; its clients, staff, and name are migrating into CBIZ while a legal shell winds down.
Marcum was an accounting and audit firm that did tax, consulting, and financial statement review work for businesses. On November 1, 2024, the larger firm CBIZ bought Marcum for $2.3 billion and split it into two parts, leaving the Marcum name as an empty shell. The company's staff has been cut by half in just two years, clients are switching to CBIZ's audit unit instead, and there is an active lawsuit tied to the Marcum brand. The one thing that matters now is whether CBIZ can smoothly combine the old Marcum staff and clients into its own operation without losing people or business to rivals like Crowe or Eide Bailly, which are also being bought and reshuffled by big investment firms.
Why
01
AI pressure: None apparent. The entity is being dissolved by its acquirer, not challenged by an AI product; AI risk now sits with CBIZ CPAs P.C., not this name. Could AI do the core job? Only partly.
02
Bigger players: CBIZ, Inc. and CBIZ CPAs P.C.. CBIZ already bought Marcum's business for $2.3B in Nov 2024, split it into two entities, and is moving clients like Nathan's Famous to CBIZ CPAs. Could a giant copy it? No, they are blocked.
03
What protects it. CPA licensure rules still require a licensed signer for audits, but that protection now sits with CBIZ CPAs P.C., not the Marcum name.
What would change this call
Marcum LLP headcount reported by Revelio Labs or similar continues falling through 2026. Confirms the legacy entity is a wind-down shell, not an operating firm.
Resolution of Lateral Investment Management v. Marcum motions (filed Feb 2026). Shows whether legal tail risk lands on CBIZ or stays isolated in the shell entity.
CBIZ discloses ex-Marcum client retention or attrition figures in 2026-27 earnings. Indicates whether integration is retaining acquired client relationships or losing them.
Resolution of Lateral Investment Management v. Marcum motions (filed Feb 2026). Shows whether legal tail risk lands on CBIZ or stays isolated in the shell entity.
CBIZ discloses ex-Marcum client retention or attrition figures in 2026-27 earnings. Indicates whether integration is retaining acquired client relationships or losing them.
Key numbers
- Headcount fell from 2,942 to 1,162 in two years
- CBIZ paid $2.3B to acquire Marcum
- Combined CBIZ entity now ~$2.8B revenue, 10,000+ staff
Named risks
- Marcum LLP brand actively winding down with no independent future post-CBIZ acquisition.
- Ongoing Lateral Investment Management v. Marcum LLP litigation with motions as of Feb 2026.
- Legacy clients continuing to migrate auditor-of-record away from Marcum name to CBIZ CPAs.
- Residual legal exposure from prior SEC/PCAOB SPAC audit quality control findings.
- Sector-wide PE consolidation (Crowe/KKR, Eide Bailly/Reverence) pressuring CBIZ integration margins.
Rivals, as read in July 2026
| Rival | Direction | Evidence |
|---|---|---|
| CBIZ, Inc. | losing to | Acquired Marcum's entire business for $2.3B, closing 2024-11-01, absorbing clients and staff |
| Withum Smith+Brown | contesting | Direct SPAC-audit rival to Marcum through 2023, per bloombergtax.com, 2023-09-29 |
| EisnerAmper | gaining on | Completed PE continuation vehicle with TowerBrook Capital, 2026-03-25, unlike absorbed Marcum |
| Crowe | gaining on | Locked up ~$3B private equity from KKR, 2026-06-11, expanding while Marcum wound down |
| Big 4 (Deloitte, EY, KPMG, PwC) | contesting | Structurally priced out of middle-market and SPAC audit segment Marcum once served |
Questions people ask
- Is Marcum LLP still an independent accounting firm?
- No. CBIZ, Inc. completed its $2.3B acquisition of Marcum LLP on November 1, 2024, splitting the firm into non-attest CBIZ, Inc. and attest CBIZ CPAs P.C. Marcum now exists only as a wind-down legal shell, per prnewswire.com, 2024-11-01.
- Who owns Marcum LLP now?
- CBIZ, Inc. (NYSE: CBZ) owns Marcum's non-attest business, while CBIZ CPAs P.C. (formerly Mayer Hoffman McCann, renamed 2024-08-22) owns the attest/audit business, following the $2.3B deal closed November 1, 2024.
- Could AI replace Marcum's auditors?
- Routine audit testing and documentation could be AI-augmented, but attest sign-off legally requires a licensed CPA firm under PCAOB rules, which is why CBIZ kept a separate licensed CBIZ CPAs P.C. entity rather than folding attest work into AI or a non-CPA parent, per cbizcpas.com, 2025-11-18.
- Who is Marcum LLP's biggest competitor?
- Historically Withum Smith+Brown was Marcum's direct rival in SPAC audits, but post-acquisition Marcum's real replacement is its own acquirer, CBIZ, Inc., which absorbed Marcum's entire business for $2.3B on November 1, 2024.
- Is Marcum LLP profitable?
- Marcum's standalone financials are no longer separately disclosed since the November 1, 2024 CBIZ acquisition; revenue is now folded into CBIZ's combined ~$2.8B annualized figure, reported at deal close per prnewswire.com.
- What happened with Marcum's SPAC audit scandal?
- The SEC charged Marcum LLP on June 21, 2023 with widespread quality control deficiencies in SPAC audits, fining the firm $10M (SEC) plus $3M (PCAOB) for shoddy quality controls, per cpapracticeadvisor.com, 2023-06-21.
Timeline
- 2026-03-23Federal court dismisses investor suit against Marcum and iLearningEngines leaders
- 2026-02-04Lateral Investment Management v. Marcum LLP litigation active with motions filed
- 2025-06-13InMed Pharmaceuticals appoints CBIZ as new auditor, replacing Marcum LLP
- 2025-02-24CBIZ CPAs makes QC 1000 quality-control adjustments post-Marcum acquisition
- 2024-11-01CBIZ completes $2.3B acquisition of Marcum, splitting attest and non-attest units
- 2024-08-22Mayer Hoffman McCann renamed CBIZ CPAs P.C. ahead of Marcum deal close
- 2024-07-31CBIZ announces definitive agreement to acquire Marcum LLP for $2.3B
- 2023-06-21SEC charges Marcum LLP with widespread SPAC audit quality control deficiencies
Revision history
23 July 2026
First assessed. Little protection left. The text above is fixed as of this date and is not edited afterwards.
In the same band
Sources
- MarcumRachlin Changes its Name to Marcum LLP
- CBIZ COMPLETES ACQUISITION OF MARCUM (2024-11-01)
- EX-99.1 CBIZ TO ACQUIRE MARCUM (2024-07-31)
- CBIZ completes Marcum acquisition (2024-11-02)
- Marcum LLP to be acquired in $2.3B deal (2024-07-31)
- Company Profile
- Marcum Number of Employees 2026 (2026-06-29)
- Mayer Hoffman McCann changes name to CBIZ CPAs (2024-08-22)
- InMed Appoints CBIZ as New Auditor (2025-06-13)
- SEC Charges Audit Firm Marcum LLP for Widespread Quality Control Deficiencies (2023-06-21)
- Marcum Fined $10M by SEC and $3M by PCAOB (2023-06-21)
- Marcum Labs