IB, or the International Baccalaureate, is a rigorous academic program offered at some high schools that combines college-level coursework with research, community service, and interdisciplinary thinking. Most students encounter it as the IB Diploma Programme (DP), a two-year curriculum taken during junior and senior year that results in an internationally recognized diploma. It’s often compared to AP classes, but the IB program works quite differently in structure, philosophy, and how students are assessed.
How the IB Diploma Is Structured
The IB Diploma Programme requires you to take six subjects, one from each of the following groups: studies in language and literature, language acquisition, individuals and societies, sciences, mathematics, and the arts. If the arts aren’t your thing, you can swap that slot for an additional science, social science, or language course instead.
Within those six subjects, you choose three or four to take at Higher Level (HL) and the rest at Standard Level (SL). Higher Level courses involve 240 teaching hours over two years, while Standard Level courses require 150 hours. Both levels are graded on the same scale, but HL courses go deeper into the material and expect you to demonstrate more knowledge and skill. Your HL choices typically reflect your academic strengths or the subjects most relevant to what you want to study in college.
The Three Core Requirements
Beyond the six subjects, every IB Diploma candidate must complete three additional components that make the program distinct from other high school curricula.
Theory of Knowledge (TOK) is a course that asks you to examine how we know what we claim to know. It covers questions about the nature of evidence, bias, and reasoning across different disciplines. You’re graded on a scale from A to E.
The Extended Essay (EE) is an independent research paper of roughly 4,000 words on a topic of your choosing. It functions like a scaled-down version of a college thesis, requiring you to develop a research question, gather evidence, and build an argument. It’s also graded A through E.
Creativity, Activity, Service (CAS) requires you to engage in creative pursuits, physical activities, and community service throughout the two-year program. Unlike TOK and the EE, CAS doesn’t receive a letter grade. Your school assesses whether you’ve completed the requirement, and you must finish it to earn the diploma.
Your TOK and EE grades combine on a matrix to earn you up to three bonus points toward your diploma total. Scoring an A on both earns the full three points. An E on either one, however, is a failing condition that disqualifies you from the diploma entirely.
How Scoring Works
Each of your six subjects is scored on a scale of 1 to 7, with 7 being the highest. That gives you a maximum of 42 points from coursework alone. Add the three possible bonus points from TOK and the EE, and the highest possible diploma score is 45. You need at least 24 points overall to earn the diploma, along with meeting all the core requirements.
IB assessment is a mix of internal and external evaluation. Throughout the program, your teachers grade internal assessments like research projects, oral presentations, and lab reports. These are then moderated by IB examiners outside your school. At the end of the program, you sit for externally graded final exams. This blend means your diploma score isn’t determined by a single test day the way an AP score is.
How IB Differs from AP
AP courses let you pick individual subjects one at a time. You can take one AP class or ten, and each ends with a single standardized exam. IB, by contrast, is a comprehensive program. You’re committing to six subjects, three core components, and a two-year timeline that’s designed to work as an integrated whole.
The teaching philosophy also diverges. AP emphasizes content mastery and college-readiness within specific disciplines. IB leans into critical thinking, interdisciplinary connections, and developing what it calls a “global perspective.” In practice, that means IB students spend more time writing research essays, giving presentations, and connecting ideas across subjects, while AP students focus more on deep content knowledge within each course.
You can sometimes take individual IB courses without pursuing the full diploma. These are called IB certificate courses, and they let you earn scores on specific subjects without completing the core requirements. This option works for students who want the IB classroom experience without the full program commitment.
College Credit and Admissions
Many universities grant credit for strong IB scores, though policies vary widely by school. As a general benchmark, the University of California system awards 8 quarter units (about 5.3 semester units) for each Higher Level exam where you score a 5 or above. Students who complete the full IB Diploma with a score of 30 or higher receive an additional 6 quarter units on top of whatever they earned from individual HL exams. Standard Level scores typically don’t earn college credit at most institutions.
For admissions, the IB Diploma signals to colleges that you’ve taken on one of the most demanding curricula available. Admissions officers at selective universities are familiar with the program and understand the workload involved. Having the diploma doesn’t guarantee admission anywhere, but it positions your transcript favorably, especially when paired with strong scores.
What It Costs
At public schools that offer IB, tuition is free, but exam fees are not. Starting with the May 2026 exam session, the fee is $123 per exam for individual course students. Full diploma candidates get a significant break: students pursuing the complete diploma pay for only one exam per year, with the school or the IB organization covering the rest. Fees are typically assessed in October when students register for their assessments.
Many schools offer fee waivers for families who qualify based on financial need, and hardship reduction requests are usually handled through your school counselor. The total cost of IB exams is comparable to AP exam fees, though the structure of who pays what depends heavily on your school’s policies and funding.
Who the IB Program Is For
IB works best for students who thrive with consistent academic pressure across multiple subjects rather than those who prefer to go deep in one or two areas and coast elsewhere. The program rewards strong writing, time management, and intellectual curiosity. If you’re the kind of student who likes connecting ideas across history, science, and literature, the interdisciplinary design will feel natural. If you’d rather specialize early and take seven AP sciences, the structure may feel restrictive.
Not every high school offers IB. The program requires schools to go through an authorization process with the International Baccalaureate organization, and only a fraction of U.S. high schools have it. If your school doesn’t offer it, transferring to one that does is an option some families pursue, but it’s worth weighing whether the logistical trade-offs make sense for your situation. You can search for authorized IB schools in your area on the IB organization’s website.