What's on the NIC Cosmetology Theory Exam? The Four Domains and Their Weights

The four NIC cosmetology theory domains at a glance

NIC's current theory bulletin says the exam "contains 110 items, of which 100 items are weighted" and that the domain percentages "represent the percentage of items from each domain." It does not say whether the percentages apply to all 110 items or only to the 100 that count. The counts below are therefore estimates, shown both ways.

Read the outline as a list of jobs, not chapter titles. Each section below rewrites NIC's lines as "can you" checks. If you can answer yes to a check and give a salon example, you have covered that line. Passy's planned prep uses the same split: the 850 questions planned for full cosmetology prep run from 382 in Hair Care and Services to 85 each in Skin and Nail.

Scientific Concepts (35%): infection control, anatomy, and chemistry

This domain is the science behind every service. It has three parts.

Infection control and safety practices. Can you:

• explain what causes diseases and infections and how they spread?
• tell sanitation, disinfection, and sterilization apart, and say what each one is for?
• show how cross-contamination happens and prevent it, including sorting single-use items from multi-use items?
• apply blood exposure procedures?
• name the requirements that OSHA and the EPA set?

The cleaning, disinfection, and sterilization guide, the blood exposure guide, and the OSHA, EPA, and SDS guide cover these lines.

Human anatomy and physiology. Can you:

• describe the structure and function of the hair and scalp, the skin, and the nails?
• recognize signs and symptoms of conditions, disorders, and diseases in each of those three?
• identify the muscles and joints of the head and face, the arms and hands, and the legs and feet, and what they do?
• explain what the nervous and circulatory systems do?

See the hair and scalp guide and the muscles, nerves, and circulation guide.

Basic chemistry used in cosmetology. Can you recognize the purpose and effects of ingredients, the interactions between chemicals, chemical reactions such as overexposure and chemical burns, and the values of the pH scale? The pH and chemistry guide works through them. Much of this domain is vocabulary you have to recall fast, and 540 flashcards planned for launch drill infection-control categories, hair growth phases, and pH.

Hair Care and Services (45%): the largest NIC domain

Nearly half the exam sits here. NIC splits it into five areas.

The outline uses "perform" and "demonstrate" even on the written exam. On paper, that means scenario questions: what you would check, choose, or do next during the service. Because this domain is so large, it pays to practice Hair Care and Services on its own, one domain at a time, in full prep at launch before you mix it with the others.

Skin Care and Services (10%) and Nail Care and Services (10%)

The two smaller domains follow the same pattern: consultation, tools, then the services.

Skin Care and Services. Can you evaluate skin type and condition, recognize contraindications, recommend services or products, and keep client records? Can you give the purpose and infection control procedure for equipment such as a steamer, implements such as tweezers, brushes, and extractors, and supplies such as creams, masks, towels, wax, and head coverings? And can you apply what you know about a basic facial, hair removal, makeup application, and electrical equipment? The skin care guide and the hair removal and makeup guide cover these lines.

Nail Care and Services. Can you evaluate the nails, recognize contraindications, recommend services or products, and keep records? Can you handle equipment such as the workstation and pedicure basin, implements such as nippers and files, and supplies such as towels, creams, and polish? And can you apply what you know about a basic manicure and pedicure, and about applying, maintaining, and removing nail enhancements? See the nail care guide and the nail enhancements guide.

One pattern runs through all three service domains: each lists "infection control procedures" for its tools, along with safe practices and ergonomics. Safety questions can therefore turn up anywhere on the exam, not only in the 35% science domain. Once you can work through the checks above, check all four NIC domains with the 20 free cosmetology practice questions and see which domain needs another pass.

The NIC theory outline for 2027 test dates

As of October 28, 2026, the bulletin above, effective July 1, 2022, and revised January 1, 2026, was still the current NIC theory bulletin, and NIC had posted no replacement. So the four domains and their weights are what to study for a 2027 test date unless your provider posts a newer bulletin. NIC's bulletin asks candidates to check their exam provider's site or nictesting.org for the most current version before testing.

One change is already under way. NIC's exam resources page says that beginning March 2026, all blood exposure procedures are being updated at the same time as exam updates or revisions. The theory outline still lists "apply blood exposure procedures," so learn the principles and follow the exact steps in your state's current bulletin.

Why other sites show 30/40/15/15 for the NIC theory exam

The weights changed. An earlier NIC cosmetology theory bulletin, effective May 1, 2016, and revised March 1, 2020, weighted Scientific Concepts at 30%, Hair Care and Services at 40%, and Skin Care and Services and Nail Care and Services at 15% each. As checked on October 28, 2026, the Arkansas Department of Health still hosted that older bulletin, and third-party study pages still quote its numbers.

The domain names did not change, which makes the mix-up easy. Check the dates printed on any outline you study from. The current one is effective July 1, 2022, with a revision date of January 1, 2026.

Check the domains too, not only the dates. As of October 28, 2026, the Korean edition of the cosmetology theory bulletin on NIC's bulletin site carried the current dates but listed four domains weighted 35%, 10%, 40%, and 15% and worded for barbering, which match NIC's barber theory outline. The Spanish and Vietnamese editions match the English 35/45/10/10. If you read the Korean edition, study from the domains above and ask your vendor to confirm.

The NIC Written Practical is a different exam

NIC also writes a Cosmetology Written Practical Examination, and its bulletin looks almost identical at first glance. It is a separate test: 75 items, of which 65 are weighted, in 120 minutes, with Scientific Concepts at 20%, Hair Care and Services at 45%, Skin Care and Services at 15%, and Nail Care and Services at 20%. If your state gives the theory exam, study from the theory outline above.

Your state may also use a non-NIC written exam. PSI's national cosmetology exam, used in California, Georgia, and Michigan, has its own outline. Its largest area is Safety and Infection Control. The NIC vs PSI comparison lines the two up, and the guide to which exam your state uses shows how to check yours.