← All guides

Is alligation still on the PTCE?

No. The word alligation does not appear anywhere in the PTCE Content Outline effective January 6, 2026, and PTCB's announcement of that outline says it was removed from the calculations area. Dilutions and concentrations did stay, and confusing the two is how people end up dropping the wrong topic.

Published August 23, 2026

Alligation is usually the last thing a student learns and the thing they drill hardest, so this is worth being precise about. Search the current outline for the word and it returns nothing: zero occurrences across both pages. PTCB's announcement of the new outline states directly that alligation came out of the calculations area, which is as unambiguous as this kind of change ever gets.

That makes it one of the cleanest calls in the whole 2026 change. There is no judgment involved, no reading between lines of a knowledge statement, and no argument about emphasis. The topic is not named anywhere in the current document, and it was named in the one this replaced.

What stayed, and why it gets confused with alligation

Knowledge area 4.1 is where the calculations live, and it reads: formulas, calculations, ratios, proportions, conversions, Sig codes, abbreviations, medical terminology, and symbols for days supply, quantity, dose, concentration, dilutions.

Concentration and dilutions are both in that sentence. So a question giving you a stock strength and a target strength and asking how much stock you need is still fair, because that is a dilution worked with C1V1 = C2V2. What is gone is the specific method of mixing two known strengths to hit a third, and the tic-tac-toe grid that goes with it.

The practical distinction is between diluting one product and combining two. Diluting is on the exam. Combining two strengths to reach a target, which is what alligation solves, is not, and dropping dilutions because you heard alligation was removed would cost you real questions.

What to do with the time

Alligation eats a disproportionate share of a student's math practice, because it is the calculation people find hardest and therefore return to most. Reclaiming those hours is the largest practical effect the 2026 outline has on a study schedule, and it lands on the topic students were most likely to be dreading.

Nine of the outline's 24 knowledge areas carry an asterisk marking them as calculation-based, and they are spread across all four domains rather than confined to Order Entry. Days supply, doses, concentrations and conversions are the ones that recur. Our guide to the math covers what is left on the current outline, and the formula sheet is free to work from without an account.

Why your book probably still teaches it

A book printed before 2025 was written for an outline where alligation was testable, and reprinting is slower than a content revision. That is not carelessness on the author's part, it is the ordinary lag of print. What matters is that a recent copyright date does not tell you the content was rechecked, so it is worth running the four checks on whatever you are using.

One limit we should state: PTCB does not publish item counts per knowledge area, so we cannot tell you how many calculation questions you will see, only which topics are eligible. Nobody outside PTCB can tell you the first thing, and anyone who claims to is guessing at data PTCB does not release to anyone, which is worth remembering the next time a product quotes you a number.

Related

• Is compounding still on the PTCE?
• Pharmacy math for the PTCE: what is actually tested in 2026
• What changed on the 2026 PTCE, and what you can stop studying