MBB
McKinsey, BCG and Bain, also called the Big Three.
- Firms
- 3
- Interviews
- Test, cases and fit
Consulting firm tiers: MBB, Tier 2, Big 4 and boutiques
Consulting firms are often sorted into four groups: MBB (McKinsey, BCG and Bain), Tier 2 strategy firms such as Oliver Wyman, Kearney, L.E.K. and Roland Berger, the consulting arms of the Big 4 accounting firms, and boutiques that focus on one industry or service. Tiers are an informal industry shorthand, not an official ranking, and lists disagree on where some firms sit. Whichever tier you aim for, the interview is a case. Soreno, an AI voice interview practice app for consulting, investment banking and other finance candidates, runs a free sample case with follow-up questions and scored feedback.
Updated
- Not official. No firm, school or public body publishes consulting tiers. They are shorthand.
- MBB. McKinsey, BCG and Bain, also called the Big Three.
- Tier 2. Strategy firms such as Oliver Wyman, Kearney, L.E.K. and Roland Berger.
- Big 4 and boutiques. Deloitte, PwC, EY and KPMG's consulting arms, and smaller specialist firms.
- One published ranking. Vault's 2026 Consulting 50 ranks firms as places to work, from a survey of consultants.
The four groups
Tiers are an informal industry shorthand, not an official ranking. No firm, school or government body publishes them, and lists online disagree about firms on the edges. This is the grouping most of them share.
Tier 2
Strategy firms beyond McKinsey, BCG and Bain.
- Often named
- Oliver Wyman, Kearney, L.E.K., Roland Berger
- Interviews
- Cases and fit
Big 4 consulting
The consulting arms of Deloitte, PwC, EY and KPMG.
- Strategy units
- Strategy& (PwC), EY-Parthenon (EY)
- Interviews
- Vary by role
Boutiques
Smaller or specialist firms, by industry or by service.
- Focus
- Life sciences, economics, pricing and more
- Interviews
- Vary most
Why lists disagree3 edges
Strategy arms
Strategy& and EY-Parthenon
Some lists put them in Tier 2 for their strategy work, others with the Big 4 that own them.
Strategy& case interviewLarge firms
Accenture and Deloitte
Large firms that do strategy work beside technology and operations work, so lists place them in different groups.
Accenture case interviewSpecialists
Firms that lead one field
A life sciences or economics firm can be a top choice in its field and still be called a boutique.
Rankings you can citeVault, 2026
Vault's lists rank firms as places to work, not by tier. The 2026 lists were published February 11, 2026, from Vault's fall 2025 survey of more than 10,000 consulting professionals, who rate their own firm on quality of life and other firms on prestige. Positions as shown on Vault's pages on October 26, 2026.
Consulting 50
North America's top five
1 Bain & Company, 2 Boston Consulting Group, 3 Analysis Group, 4 Inizio Ignite, Putnam, 5 Roland Berger.
Vault Consulting 50Boutiques
Best Boutique Consulting Firms, top three
1 ghSMART, 2 Cirque Analytics, 3 Inizio Ignite, Putnam.
Vault: Best Boutique Consulting Firms
From Vault: the 2026 rankings (Feb 11, 2026), Vault Consulting 50 and Vault: Best Boutique Consulting Firms.
How interviews differ by tier
Almost every firm here interviews with cases and fit questions. What changes is the test before them and how many rounds follow, from each firm's own pages.
MBB
Each firm has its own online test: McKinsey Solve, BCG's online case and Bain's digital assessment. Then case interviews beside McKinsey's PEI, BCG's skills and team interviews or Bain's fit questions.
Tier 2
Kearney says general consulting candidates typically have four to five interviews. Roland Berger gives permanent hires an online analytics test, then a recruiting day. L.E.K. lets you apply to one office a year.
Big 4
It depends on the role. Deloitte US says two to three rounds. PwC US emails most entry-level applicants an assessment soon after they apply, and most Advisory roles have a case. Strategy& UK's first round is two case interviews.
Boutiques and specialists
These vary the most. ZS has behavioral, case and subject matter interviews. Alvarez & Marsal may ask for a case study, a business plan or a technical assessment.
From Kearney: recruiting process, Roland Berger: hints and tips, L.E.K.: apply, Deloitte US: recruiting tips, PwC US: entry level recruiting, Strategy& UK: graduates and interns, ZS: interview process and Alvarez & Marsal: early careers FAQ.
Tier 2, Big 4 and specialist firms
Each card is what the firm's own careers page says about its process, read in October 2026, and our full guide. The group is how lists usually place the firm, not something the firm says. MBB has its own page.
Oliver Wyman
- Usually grouped as
- Tier 2
- Process
- Conversational and case interviews
Conversational interviews about you, and case interviews on real-world problems in which you treat the interviewer as your client. The global page describes no test. It publishes six sample cases.
Kearney
- Usually grouped as
- Tier 2
- Process
- Four to five interviews
General consulting candidates typically have four to five interviews, behavioral and case, conducted by consultants. Some roles may add a competency assessment, which Kearney doesn't describe.
L.E.K. Consulting
- Usually grouped as
- Tier 2
- Process
- Several rounds, one office a year
Several rounds of experiential and case interviews, with quantitative or strategic cases, varying by region and level. Its official pages describe no test. You can apply to one office a year.
Roland Berger
- Usually grouped as
- Tier 2
- Process
- Online test, then a recruiting day
Candidates for permanent jobs whose profile fits take an online analytics test, then a recruiting day of personal fit and case interviews, then a final interview with a member of the management team in your future area. Interns go straight to the recruiting day.
Strategy&
- Usually grouped as
- Big 4 strategy arm
- Process
- UK: a test, then two cases
In the UK, an online assessment, then a first round of two interviews of about 45 minutes: an open, unstructured case and a structured one on slides that reflect a real client project.
EY-Parthenon
- Usually grouped as
- Big 4 strategy arm
- Process
- Australia: blind case interviews
In Australia, two or three rounds. The first is two blind problem-solving interviews, where the interviewer knows nothing about you, followed, usually that day, by a more traditional interview.
Deloitte
- Usually grouped as
- Big 4
- Process
- US: two to three rounds
US candidates should expect two to three rounds, held by phone, video or in person. Whether they are behavioral, technical or case interviews depends on the role. A recruiter usually reaches out within one to two weeks.
PwC
- Usually grouped as
- Big 4
- Process
- US: an online assessment first
In the US, an online assessment soon after you apply, then live virtual interviews. Most Advisory roles have a case interview.
KPMG
- Usually grouped as
- Big 4
- Process
- US: two video interviews
US students get two live video interviews with business leaders, and most decisions come within two weeks. KPMG US publishes no case format for students.
ZS
- Usually grouped as
- Specialist
- Process
- Two to four rounds
Typically two to four rounds of behavioral, case and subject matter expertise interviews, varying by role and location. Some roles take an online assessment of logical, quantitative and qualitative reasoning.
FTI Consulting
- Usually grouped as
- Specialist
- Process
- Video, tests, then interviews
Early careers: a pre-recorded video interview and online assessments such as numerical and written tests, then interviews that may include a case study, a technical interview or a group exercise. It varies by country.
Alvarez & Marsal
- Usually grouped as
- Specialist
- Process
- Varies by role
The number of interviews varies by role, and you may be asked for a case study, a business plan or a technical assessment. Its Talent team tells you how to prepare.
8 questions every tier asks
Our own wording. Firms in every group ask these in their own style, with what a strong answer does.
Fit3 questions
Asked at nearly every firm, often at the start of a round.
Why consulting?
What a strong answer does
What the work is, and one moment from your own experience that drew you to it. Keep it under a minute. Practice it, see a model answer
Why this firm?
What a strong answer does
Something you can only say about this firm, such as an industry it is known for or a person you spoke to. Practice it, see a model answer
Tell me about something difficult you achieved.
What a strong answer does
The goal, the obstacle that nearly stopped you and the choices that got you past it. Practice it, see a model answer
Cases5 questions
The shapes that recur across firms' sample cases.
A regional grocery chain's profits fell 20% in two years. Why?
What a strong answer does
Split profit into revenue and cost, go one level deeper on each, then say which branch you'd test first. Practice it, see a model answer
Should a European e-bike maker enter the US?
What a strong answer does
Market size and growth, rivals, the client's edge and the cost of getting in. End with yes or no. Practice it, see a model answer
Estimate the annual US market for electric scooters.
What a strong answer does
Choose between starting from riders or from units sold, and give the reason. A second route checks the total. Practice it, see a model answer
How could a movie theater chain grow its revenue?
What a strong answer does
Group ideas before listing them: more visits, more spent per visit, new uses for the building. Practice it, see a model answer
The CEO asks for your recommendation. What do you say?
What a strong answer does
Lead with the decision, back it with two numbers, flag the biggest risk and say what you would do first. Practice it, see a model answer
Mistakes and how to prepare
Where candidates slip
Treating a tier list as fact
Lists disagree, and none is official. Choose firms by the work, the office and the people you meet.
Expecting a lighter process outside MBB
Tier 2, Big 4 and specialist firms run full case interviews too, and some add tests or extra rounds.
Reading Vault's list as a tier list
The Vault Consulting 50 blends consultants' ratings of their own firm with prestige ratings of other firms. It ranks firms as employers, not by tier.
How to prepare across tiers
One base of case and fit practice carries to every group.
Step 1
List firms in more than one group
MBB tends to open applications earlier than the Big 4 and many boutiques, so a list across groups spreads your interviews out.
Step 2
Read each firm's process
Tests, rounds and case styles differ firm by firm, even within a tier.
Step 3
Do cases out loud
Practice cases you lead and cases the interviewer steers. Do the math by hand.
Step 4
Tailor why this firm
A Tier 2 or boutique interviewer will ask why them. Name the industry or kind of work that draws you there.
Practice for any tier, out loud
Soreno's AI interviewer runs a full case with exhibits and math checks, asks follow-up questions, then scores it. Start your free week. Soreno is not affiliated with any firm on this page.
Questions people ask
Is there an official ranking of consulting firms?
No. Tiers are an informal industry shorthand, and no firm, school or government body publishes one. Vault publishes yearly lists of the best consulting firms to work for, based on its survey of consultants.
What are Tier 2 consulting firms?
Strategy firms beyond McKinsey, BCG and Bain. Oliver Wyman, Kearney, L.E.K. and Roland Berger are on nearly every list. Some lists add Strategy&, EY-Parthenon and others.
What are boutique consulting firms?
Smaller firms that focus on one industry or one kind of work. Vault's 2026 Best Boutique Consulting Firms list puts ghSMART first, Cirque Analytics second and Inizio Ignite, Putnam third.
What is the Vault consulting ranking?
The Vault Consulting 50 ranks the best consulting firms to work for in North America. The 2026 list, published February 11, 2026, comes from a fall 2025 survey of more than 10,000 consulting professionals and puts Bain first, BCG second and Analysis Group third. Vault also publishes regional and boutique lists.
Is Big 4 consulting Tier 2?
Lists differ. Most keep the Big 4 as their own group and put their strategy arms, Strategy& and EY-Parthenon, next to Tier 2.
How does pay compare across tiers?
MBB base pay is higher, and the gap is widest with the Big 4. Median base for the title most MBA hires join at is $192,000 at McKinsey, $190,000 at BCG and $192,000 at Bain, $185,000 at L.E.K., $172,500 at Kearney, $138,650 at PwC and $129,699 at Deloitte, in US H-1B filings from January 2025 to June 2026.