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 firms, the Big 4, technology/IT consulting, boutique and specialty firms, economic consulting, and HR/communications specialists. Each type targets different clients, runs a different interview, and sends graduates to different exits. Picking the right type is the first real decision in consulting recruiting.

Types of Consulting Firms at a Glance

Based on 5,000+ case interview sessions on our platform, candidates preparing for MBB cases over-prepare for the quant and under-prepare for the structuring — and candidates preparing for boutiques do the opposite. Knowing the firm type tells you which half of your prep matters more.

MBB (McKinsey, BCG, Bain): Pure Strategy at the Top

MBB refers to McKinsey & Company, Boston Consulting Group, and Bain & Company — the three firms that sit at the top of the prestige hierarchy globally. Together they generate roughly $40B in revenue and employ about 85,000 consultants worldwide in 2026 (Wikipedia Big Three 2026; Management Consulted 2026).

• McKinsey — largest by revenue (~$16B) and office count (130+). Strong in financial services, public sector, and pharma.
• BCG — second in revenue (~$13.5B, 2024) and growing fastest. Thought-leadership brand (BCG Matrix, Experience Curve). Strong in industrial goods, TMT, and energy.
• Bain — smallest and most selective by headcount. Dominant in private equity due diligence; ~30% of revenue from PE clients.

All three run demanding case interview processes. For firm-specific prep see our McKinsey case interview guide, BCG case interview guide, and Bain case interview guide. For the full MBB overview, see what is MBB consulting?.

Tier 2 Strategy (Oliver Wyman, Kearney, L.E.K., Strategy&, EY-P)

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 are slightly higher (2–5%) but the work is often indistinguishable from MBB at the project level.

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

Tier 2 firms tend to reward industry specialization in recruiting. A candidate with a pharma background gets a real edge at L.E.K.; a finance background edge at Oliver Wyman.

Big 4 Consulting (Deloitte, PwC, EY, KPMG)

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

• Deloitte — largest Big 4 consulting practice. Monitor Deloitte handles strategy; Deloitte S&O handles broad advisory. See our Deloitte case interview guide.
• PwC — Strategy& is the dedicated strategy arm; PwC Consulting handles tech and advisory. See our PwC case interview guide.
• EY — EY-Parthenon (strategy) + EY Consulting (advisory, tech). See our EY case interview guide.
• KPMG — KPMG Global Strategy Group (strategy) + broad KPMG Advisory. See our KPMG case interview guide.

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 full comparison versus MBB, see Big 4 vs MBB consulting and our Big 4 consulting firms overview.

Tech / IT Consulting (Accenture, Capgemini, IBM 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 usually last 6–24 months.

• Accenture — largest tech consultancy by headcount (700K+). Accenture Strategy is a distinct smaller strategy arm. See our Accenture case interview guide.
• Capgemini / Capgemini Invent — strong in Europe, deep in engineering services.
• IBM Consulting — technology-first firm with a growing strategy practice. See our IBM Consulting case interview guide.
• ZS Associates — tech-enabled commercial consulting, dominant in life sciences. See our ZS Associates case interview guide.
• Slalom, West Monroe — mid-market tech/digital firms.

Pay at entry is comparable to Big 4 broad consulting. Exits skew toward product management, corporate IT leadership, and tech startups rather than finance or private equity.

Boutique and Specialty Firms

Boutiques focus on a single function (pricing, innovation, restructuring) or single industry (life sciences, energy, PE). Depth over scale — a Simon-Kucher pricing consultant sees 30+ pricing projects in 2 years versus maybe 3 at MBB.

• Simon-Kucher — global pricing specialist. See our Simon-Kucher case interview guide.
• Alvarez & Marsal — restructuring and turnaround specialist. See our Alvarez & Marsal case interview guide.
• Innosight — innovation and growth strategy 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, litigation. See our FTI case interview guide.

Economic Consulting and Financial Advisory

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

• Analysis Group — largest private economic consultancy. See our Analysis Group case interview guide.
• Cornerstone Research — litigation and antitrust specialist. See our Cornerstone Research case interview guide.
• NERA Economic Consulting — 500+ economists across 23 offices. See our NERA case interview guide.
• Charles River Associates — ~800 consultants, strong in antitrust and finance. See our Charles River Associates guide.
• Compass Lexecon — economic analysis for regulators and courts. See our Compass Lexecon case interview guide.

Interviews at economic consulting firms lean more heavily on applied microeconomics, econometrics, and regression reasoning than classic strategy case structure.

Comparison Table: All Types Across 6 Axes

For the full comparison of firms across prestige, pay, and work type, see our management consulting firms ranking.

Test Your Knowledge

Sources and Further Reading (checked April 13, 2026)

• Hacking the Case Interview — Tier 2 Consulting Firms 2026: hackingthecaseinterview.com
• Leland — Tier 2 Consulting Firms 2026: joinleland.com
• Statista — Management consulting industry global revenue: statista.com
• Wikipedia — Big Three management consultancies: en.wikipedia.org/wiki/Big_Three_(management_consultancies)
• Consultancy.uk — Consulting industry pyramid evolution 2026: consultancy.uk
• Wall Street Oasis — 2026 Strategy Consulting Firms Tier List: wallstreetoasis.com

Related reading on Road to Offer: What is a consulting firm? · Strategy vs management consulting · What is MBB consulting? · Big 4 vs MBB consulting · Big 4 consulting firms · Management consulting firms ranking · How to get into consulting · Consulting career path