Types of Consulting Firms: MBB, Tier 2, Big 4, Boutique

Consulting firms cluster into seven recognized types in 2026: MBB (the Big 3), Tier 2 strategy, Big 4, technology/IT, boutique and specialty, economic consulting, and HR/communications. If you need the baseline definition first, read what is consulting. Each type targets different clients, runs a different interview, and feeds different exit paths. Picking the right type is the first real decision in consulting recruiting.

What are the main types of consulting firms?

The 2026 industry breaks into seven categories: MBB, Tier 2 strategy, Big 4, tech/IT, boutique/specialty, economic consulting, and HR/comms specialists. The same client (say, a Fortune 500 CFO) might hire different types for different jobs in the same year. The categories overlap in messy ways, but they still predict interview style, compensation band, and exit opportunities reliably.

Candidates preparing for MBB cases tend to over-prepare quant and under-prepare structuring; candidates preparing for boutiques do the opposite. Knowing the firm type tells you which half of your prep matters more, and whether you also need to retool for government and public-sector case interviews. For a side-by-side of selectivity, pay, and case style across the top brackets, see MBB vs boutique vs Tier 2 consulting firms.

What are the Big 3 (MBB) consulting firms?

MBB refers to McKinsey, BCG, and Bain. Together they generate roughly $35B in revenue and employ about 85,000 consultants worldwide (Wikipedia Big Three; Management Consulted 2026).

McKinsey & Company

Largest by revenue (~$16B) and office count (130+). Strong in financial services, public sector, and pharma. See our McKinsey case interview guide.

Boston Consulting Group (BCG)

Second by revenue (~$13.5B) and growing fastest. Thought-leadership brand (BCG Matrix, Experience Curve). Strong in industrial goods, TMT, and energy. See our BCG case interview guide.

Bain & Company

Smallest and most selective by headcount. Dominant in private-equity due diligence with ~30% of revenue from PE clients. See our Bain case interview guide.

What are Tier 2 strategy firms?

Tier 2 is the strategy peloton: firms that compete directly with MBB on many mandates but sit a rung below in brand recognition. Acceptance rates run 2-5%, and the project-level work is often indistinguishable from MBB.

• Oliver Wyman: financial-services powerhouse, also strong in healthcare.
• Kearney case interview guide: strategy plus deep operations and procurement.
• L.E.K. / LEK case interview guide: strongest in healthcare, life sciences, and PE diligence.
• Roland Berger case interview guide: Europe's largest strategy consultancy.
• Strategy& (PwC): ~3,800 consultants, ~$1.3B revenue, formed from PwC's 2014 Booz & Company acquisition.
• EY-Parthenon / EYP case interview guide: EY's strategy arm, often cited closest to MBB.
• Monitor Deloitte case interview guide: Deloitte's strategy arm from the 2013 Monitor Group acquisition.

"Tier 2 firms reward industry specialization in recruiting. A pharma background gets a real edge at L.E.K., a finance background at Oliver Wyman." Hacking the Case Interview 2026 Tier 2 report.

Free resource: practice MBB and Tier 2 cases

Run a free case with AI scoring on structure, math, and synthesis, calibrated to MBB and Tier 2 standards.

What do Big 4 consulting firms do?

The Big 4 (Deloitte, PwC, EY, KPMG) started as audit firms and scaled into consulting over three decades. Combined they employ 1.5M+ globally, with consulting roughly a third of that. Practices span strategy, implementation, technology, risk, tax advisory, and human capital.

• Deloitte: largest Big 4 consulting practice. Monitor Deloitte handles strategy; Deloitte S&O handles broad advisory.
• PwC: Strategy& is the strategy arm; PwC Consulting handles tech and advisory.
• EY: EY-Parthenon (strategy) plus EY Consulting (advisory, tech).
• KPMG: KPMG Global Strategy Group (strategy) plus broad KPMG Advisory.

The practical takeaway: "Big 4 consulting" is not a single career. Joining Monitor Deloitte is closer to BCG than to Deloitte's broad advisory practice. For the head-to-head comparison, see Big 4 vs MBB consulting.

What is tech and IT consulting?

Tech consulting firms focus on designing, building, and implementing technology: enterprise systems, cloud migrations, AI platforms, data infrastructure. They hire technologists as often as business generalists, and engagements typically run 6-24 months.

• Accenture: largest tech consultancy by headcount (700K+). Accenture Strategy is a distinct smaller strategy arm.
• Capgemini / Capgemini Invent: strong in Europe and engineering services.
• IBM Consulting: technology-first with a growing strategy practice.
• Slalom and West Monroe: mid-market tech and digital firms.

Entry pay matches Big 4 broad consulting. Exits skew toward product management, corporate IT leadership, and tech startups rather than finance or private equity.

What are boutique and specialty consulting firms?

Boutiques pick a single function (pricing, innovation, restructuring) or single industry (life sciences, energy, PE) and go deep. A Simon-Kucher pricing consultant runs 30+ pricing projects in 2 years versus maybe 3 at MBB.

If you're choosing between broad advisory and pure strategy work, weigh the strategy-versus-management-consulting tradeoff before picking a firm tier.

• Simon-Kucher: global pricing specialist.
• ZS Associates: commercial-analytics specialist, dominant in pharma and life sciences.
• Alvarez & Marsal: restructuring and turnaround.
• AlixPartners: turnaround, restructuring, and performance improvement.
• Innosight: innovation and growth boutique founded by Clayton Christensen.
• OC&C Strategy Consultants: consumer and retail strategy boutique.
• Mars & Co: ultra-selective pure strategy boutique.
• FTI Consulting: financial advisory, restructuring, and litigation.

What is economic consulting?

Economic consulting firms sit at the intersection of consulting, finance, and law. They support antitrust cases, M&A regulatory review, litigation, and complex valuation. Clients are typically law firms and regulators rather than corporate executives.

• Analysis Group: largest private economic consultancy.
• Cornerstone Research: litigation and antitrust.
• NERA: 500+ economists across 23 offices.
• Charles River Associates: ~800 consultants, strong in antitrust and finance.
• Compass Lexecon: economic analysis for regulators and courts.

Economic interviews lean more on applied microeconomics, econometrics, and regression reasoning than classic strategy case structure.

How do the seven types compare across pay, work, and exits?

For exact base, bonus, and signing comp by firm and tier, see the 2026 Consulting Salary Report.

How do you choose the right type of consulting firm?

Three filters cover most decisions.

What kind of work do you want?

Pure strategy lives at MBB and Tier 2. Implementation and tech delivery live at Big 4 and tech firms. Litigation and antitrust live at economic consulting. Pricing, restructuring, and innovation live at boutiques.

What is your target exit?

PE exits concentrate at MBB (especially Bain) and a few Tier 2 firms. Operations and tech leadership exits dominate Big 4 and tech consulting. Specialist leadership and academia come out of boutiques and economic consulting.

What is your background?

Generalists do best at MBB, Tier 2, and Big 4. Engineers fit cleanly into tech consulting. Economists and law-adjacent candidates fit economic consulting.

Each firm type runs its own recruiting calendar; the recruiting deadlines calendar tracks the dates by firm so you don't miss a window. Once your target is picked, the complete consulting toolkit covers cases, math drills, and PEI prep from there.

Sources (checked June 17, 2026)

• Hacking the Case Interview Tier 2 firms 2026: hackingthecaseinterview.com/pages/tier-2-consulting-firms
• Leland Tier 2 firms 2026: joinleland.com
• Statista management consulting global revenue: statista.com
• Wikipedia Big Three management consultancies: en.wikipedia.org/wiki/Big_Three_(management_consultancies)
• Consultancy.uk consulting industry pyramid 2026: consultancy.uk
• Wall Street Oasis 2026 strategy firm tier list: wallstreetoasis.com