How the MCAT Works

By: Dave Roos
You'll have to take the MCAT if you want to join these medical students someday.
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If you want to be a doctor when you grow up, you'll have to get past the MCAT first. The Medical College Admissions Test (MCAT) is a required part of the admissions process at every medical school in the U.S. Each year, approximately 70,000 people take the MCAT, widely considered the hardest and most stressful standardized admission test of them all [source: Arenson].

Tests like the SAT, GRE, GMAT and LSAT are designed to assess your overall critical thinking and problem-solving skills, but shy away from testing specific subject area knowledge. That's not the case with the MCAT, which drills test-takers on a wide range of natural science topics spanning undergraduate coursework in physics, chemistry and biology.


At more than five hours long, the MCAT is a marathon exam. Incredibly, before the test became fully computerized in 2007, it was a mind-melting eight and a half hours long [source: Ray]. Studying for the MCAT is a full-time job for pre-med students who are intent on landing a coveted slot at a competitive medical school. In 2009, over 42,200 applicants applied for only 18,390 slots at U.S. medical schools, meaning that more than two students fought for each available space [source: Goldstein].

When medical schools consider an applicant, they weight his or her MCAT scores equally with undergraduate grade point average [source: The Princeton Review]. The lowest possible score on the MCAT is a three and the highest is 45. While the average MCAT score is around a 24, you'd need a score well over 30 to get into the nation's top programs [source: The Princeton Review].

Keep reading to learn exactly what kinds of questions are included on the MCAT and how you can prepare to take this imposing and important exam.


Registering for the MCAT

The MCAT is administered by the American Association of Medical Colleges (AAMC). Like the SAT, the MCAT is given on a set number of dates throughout the year and you need to reserve a seat ahead of time. There are no walk-in registrations. The AAMC posts an updated calendar of test dates on its Web site.

If you're applying to medical school the same year that you're taking the MCAT, the AAMC recommends that you register take the test before September. Taking the test early assures that you'll have enough time to send your scores to medical schools ahead of their application deadlines. If you wait until September and something goes wrong -- you get sick or there's a computer malfunction at the testing facility -- you could miss your only chance to get your scores in on time.


There are two registration deadlines for each test date: regular and late. If you register on or before the regular deadline (two weeks before the test date), you pay the normal registration fee ($230). But if you wait longer, you pay a late fee ($55) on top of the registration fee. The late registration deadline is a week before the test date. To ensure that you get the test date you want, the AAMC recommends registering at least 60 days in advance [source: AAMC].

You must register for the exam through the AAMC Web site. First you need to log into the AAMC system and receive an AAMC ID. When you create an AAMC ID, make sure to enter your full name exactly how it's spelled on the government-issued photo ID you'll bring to the testing center [source: AAMC]. If you have two last names, include both. If you usually go by an Anglicized version of your name, don't use it for your AAMC ID. If you show up on test day without an identification that matches the name on record, you won't be allowed to take the test.

During the online registration process, you'll be asked to enter your contact information, Social Security number, and to identify the undergraduate institution that will distribute your MCAT scores to medical schools. The system will also help you locate the nearest testing locations and available testing dates.

Once you choose an available test date and location, pay the registration fee to reserve your seat. Payment must be in the form of a debit or credit card (MasterCard or Visa only) -- no cash or checks. You must print out the confirmation page from your registration and bring it with you, along with your government-issued photo ID, on the scheduled testing day.

Now let's take a closer look at what kinds of questions are on the MCAT.


Structure of the MCAT

More than any other standardized test, the MCAT tests specific scientific knowledge.
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The MCAT is composed of three multiple-choice sections (Physical Sciences, Verbal Reasoning and Biological Sciences) and a Writing Sample. Throughout the exam, you will be tested on your knowledge of the basic concepts of the natural sciences (biology, general and organic chemistry, and physics).

Rather than testing your ability to memorize facts, the MCAT challenges you to use your scientific knowledge base to think critically and solve complex problems. Although there's no dedicated math section on the MCAT, you'll need to use basic algebra and trigonometry concepts to answer certain questions.


There are 52 multiple-choice questions in the Physical Sciences section. Most of the questions are "passage-based," meaning they refer to short passages of text formatted like scientific journal articles, research reports, data analysis or scientific editorials [source: The Princeton Review]. Some of the passages cover intentionally obscure scientific concepts [source: Kaplan]. The idea is to test how well you can draw out salient facts from the text and use them intelligently. There are also 13 independent questions that don't relate to a passage of text.

The Biological Sciences section is identical in structure to Physical Sciences with free-standing and passage-based questions covering basic concepts of biology and organic chemistry.

The Verbal Reasoning section is similar to the Reading Comprehension sections on the SAT and GRE, but the passages selected for the MCAT are much more dense and scholarly (i.e. difficult to read) [source: Kaplan]. In total, there are seven 600-word passages taken from the humanities, social sciences and natural sciences. The questions test your ability to recognize main ideas, identify the author's tone, draw conclusions, break down arguments and apply information from the text to new hypothetical situations [source: Kaplan].

The Writing Sample consists of two half-hour essays in response to two short prompts. The prompt can be an opinion, a common belief, a philosophical assertion or a policy decision concerning non-scientific and non-technical subjects like history, political science, business, art or ethics [source: Kaplan]. Each prompt is followed by a set of specific tasks, such as: provide your own interpretation of the statement, or describe a specific situation where the statement would not hold true.

The Writing Sample Tests your ability to formulate and communicate an argument in standard written English and to support your argument using logical and relevant examples [source: The Princeton Review].

Sounds easy enough, right? Just in case, keep reading for some tips on preparing for the MCAT.


Preparing for the MCAT

Tip number one: Start early. Give yourself as much time as reasonably possible to prepare for the exam. The first step is to familiarize yourself with each section of the test using information on the AAMC website and in the free bulletin, 2010 MCAT Essentials.

The next step is to take a free practice test. The AAMC offers a free online version of the full MCAT exam through its online store: The Princeton Review Web site also provides a free online practice test. By taking a practice test, you can familiarize yourself with the computer-based testing format and get an idea of your strengths and weaknesses.


Now it's time to hit the books. The AAMC publishes detailed content outlines for each section of the test. The Physical Sciences guide, for example, is ten pages long, listing every scientific principle and topic within general chemistry and physics that may be covered in the MCAT. There are similar content outlines for Biological Sciences and Verbal Reasoning. For the writing section, the AAMC provides a list of over hundred sample essay prompts from past exams.

All of the science content on the MCAT should be material that you studied in one or more of your undergraduate courses. To study, you can either use your old textbooks and notes or you can purchase an MCAT study guide. The AAMC sells the Official Guide to the MCAT Exam, or you can choose from dozens of other titles from test prep companies like The Princeton Review and Kaplan.

Don't overlook the Verbal Reasoning section and the Writing Sample. A lot of people think these sections are the easiest, but they can cause problems if you're not prepared.

The AAMC recommends that you study with a partner. You can help motivate each other to stick to regularly scheduled study sessions and you can compensate for each other's weaknesses. As you prepare, continue to take practice tests to gauge your improvement. The AAMC sells online practice exams for $35 a piece or you can buy books of practice questions and practice tests.

If you feel like self-study isn't enough, you can sign up with a test prep service. They offer individual and small-group tutoring, classroom instruction and even live online tutoring. Classes and tutoring sessions cover the core scientific content areas, critical thinking skills, strategies for extracting information from passages of text, techniques for increasing speed and endurance and computer-based practice testing to familiarize yourself with the format [source: Kaplan].

These courses aren't cheap. Classes can cost more than $1,800 and private tutoring can be as much as $6,000. But many of them come with a money-back guarantee if your score doesn't improve or if you're simply not satisfied with your performance on the real exam.

After all the studying is done, there is one last bit of preparation to do: getting ready for test day itself. Read all about it on the next page.


MCAT Test Day

Unlike these medical students, you can't bring any study aids with you on test day.
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There are a strict set of rules and procedures surrounding the MCAT to ensure standardized testing conditions and discourage cheaters. By familiarizing yourself with these rules, you can avoid hassle and potential problems on test day.

The AAMC suggests that you arrive at your testing location at least 30 minutes before the scheduled start of the exam. If you are late for whatever reason (even bad weather) you forfeit your registration fee.


Bring a valid, government-issued photo ID with an expiration date and a signature. The most common forms of ID are a driver's license or a passport. Other accepted IDs are military IDs and state-issued ID cards. The AAMC does not accept school IDs, library cards, temporary IDs or IDs from government or government-sponsored institutions [source: AAMC]. During check-in, the test administrator will scan your photo ID and take digital copies of your fingerprints.

Once you're signed in, you'll be allowed into the testing room one-by-one to take the exam. This means that each student starts the exam at a slightly different time. It's not unusual to wait a half-hour or more once you arrive before you complete the sign-in process, so you may end up starting the exam after the scheduled time. Don't worry; you'll still have the full five hours and 25 minutes to complete it.

You aren't allowed to bring anything into the testing room except the clothes on your back and a pair of approved ear plugs in their original, unopened packaging. You can't bring in any personal items (cell phones, books, backpacks, food). You can keep those items in a secure area provided at the testing center. You also can't wear a hat during the test. The administrator provides each test taker with scratch paper (or dry erase boards), pencils and industrial ear covers.

If you have a learning disorder or psychiatric condition that requires special consideration, you can apply to the AAMC for special accommodations. If you have diabetes or other chronic physical conditions, you can also apply to be allowed to take food, drink, insulin, prosthetic devices or personal medical items into the testing room.

There are three optional 10-minute breaks scheduled into the testing day. If you want to leave the testing room during these breaks, you need to submit your fingerprints and scan your photo ID each time you leave and re-enter the room. During breaks, you can't use a cell phone or consult any study materials.

If you complete your exam and have a bad feeling about your performance, you have the option of "voiding" it. That means that the test won't be scored. Once you complete the exam, you only have five minutes to decide if you want to void your score or not. You forfeit your registration fee even if you void the exam. If you void the exam, no one else will know that you took the test, but it will count toward the three maximum times you're allowed to take the test each year [source: AAMC].

Let's finish up with a look at how the MCAT is scored.


Scoring the MCAT

Approximately 30 days after taking the exam, you'll receive an official MCAT score report with four separate scores for each section of the test. The multiple-choice sections are given a "scaled" score from one to 15. Since there are many more than 15 questions in each of those sections, the score does not represent a "raw" tally of right and wrong answers. Instead, it is weighted to reflect the difficulty of the test questions.

Every MCAT exam contains slightly different questions of varying difficulty. Your scaled score reflects the difficulty of the questions you answered correctly. Therefore, it's possible for two people with very different raw scores to get the same scaled score. The goal is to create an accurate assessment of overall skill level of the test-taker. The same test-taker would be expected to receive the same scaled score on any specific MCAT exam, even if his raw scores are different [source: AAMC].


Each of the two essays in the writing section is scored twice, once by a human reader and once by a computer. Each essay is assigned a raw score from one to six. Those four raw scores (two for each essay) are added up to a total raw score. The total raw score is then converted to an alphabetic scale from J though T, with J being the lowest score and T the highest (presumably A through F was too boring...).

The average MCAT score on each of the three multiple-choice sections is eight and the average score of the writing section is O [source: The Princeton Review]. That average scores goes up considerably depending on the competitiveness of the medical school. The average accepted student to Harvard Medical School, for example, scores an 11 on Verbal Reasoning, 12 on Physical Sciences, 12 on Biological Sciences and Q for the Writing Sample [source: The Princeton Review].

You can send your MCAT scores directly to the schools to which you're applying through the American Medical College Application Service (AMCAS). Once you register online for the service, your latest scores will be automatically sent to the schools of your choice.

If you want to send your scores to a school that doesn't participate in the AMCAS, you can access the online MCAT Testing History System (MCAT THx) with your AAMC ID and specify the schools to which you want to send your scores or print out a score report and send them by mail [source: AAMC].

Keep reading for more information on graduate school admissions.


Lots More Information

Related HowStuffWorks Articles

More Great Links


  • AAMC. "2010 MCAT Essentials"
  • AAMC. "Registration Tips"
  • Arenson, Karen. "Computer Gets it Wrong in Medical Admission Test." The New York Times. January 30, 2007
  • Kaplan. "How the MCAT Program Works"
  • Kaplan. "MCAT Physical Sciences"
  • Kaplan. "MCAT Verbal Reasoning"
  • Kaplan. "MCAT Writing Sample"
  • The Princeton Review. "MCAT Information"
  • The Princeton Review. "MCAT Physical Sciences"
  • The Princeton Review. "MCAT Scoring"
  • The Princeton Review. "MCAT Writing Section"
  • Ray, John. "MCAT to be significantly shorter, completely computerized in 2007." The Daily Orange. Syracuse University. October 18, 2006