Is the ACT Science section optional? What changed and should you take it

Yes. ACT Science is optional for national testing: online from April 2025, and for all national administrations including paper from September 2025. Your Composite score is now the average of English, math and reading only, so taking Science cannot lower your Composite. It is reported as a separate 1 to 36 score. For school-day testing in spring 2026 and later, the state or district decides, not the student.

That is the fact. The decision is harder, because "optional" does not mean "irrelevant," and because you cannot change your mind afterward without sitting the entire test again.

What exactly changed, and when

ACT rolled the enhanced test out in stages, which is why so much advice you will find is confidently wrong. It depends entirely on which stage the writer was looking at.

• April 2025: the enhanced ACT began for national test dates taken online only. Science became optional and the Composite became English, math and reading.
• September 2025: it applied to all national administrations, including paper, and to international testing. From that point every national Composite reflects three sections.
• Spring 2026: it reached state and district school-day testing. Here the important wrinkle is that the decision on whether Science is optional belongs to the state or district, not to the individual student.

Composite scores from tests taken before September 2025 were not recalculated. If you tested in 2024, your Composite still includes Science and it stays that way.

Does skipping ACT Science change your Composite score?

Barely, and ACT has published the numbers rather than leaving it to speculation. The correlation between the three-section Composite and the old four-section Composite is 0.99. Between 91% and 94% of students score within one point either way, and roughly 42% to 47% get an identical Composite.

So the honest framing is "usually within a point." Not "no difference." That one point is not evenly distributed either, and this is the part that should drive your decision:

• If Science was your strongest section, the new Composite quietly takes away a score that was pulling your average up.
• If Science was your weakest section, the new Composite has done you a favor you did not have to work for.
• If Science sat in the middle of your sections, this changes essentially nothing.

Pull up your last practice test and check which of those three you are. That takes thirty seconds and it is more useful than any general advice, including this article.

Should you take the optional ACT Science section?

For most students, yes. The reason is asymmetry: the downside is bounded and small, the upside is real.

What it costs you: 40 extra minutes on test day (165 minutes instead of 125), a small add-on fee, and the prep time to not embarrass yourself. What it cannot do is lower your Composite, because the Composite no longer includes it. That is a genuinely unusual deal on a standardized test. You are being offered an extra score that can only help.

What it can get you:

• A school that still wants it. Some colleges continue to compute their own totals that include Science. ACT says so explicitly. You do not want to discover this in October of your senior year.
• A STEM score. Take Science with math and you get a STEM score, the average of the two. Engineering and science programs read it.
• Optionality. Your college list in your junior year is not your college list when you apply.

The case for skipping it is narrower than the internet suggests, but it is real: you are certain no school on your list wants Science, you are not applying to STEM programs, your test-day stamina is genuinely a limiting factor, and the 40 minutes and prep hours are better spent lifting a weak English score. That is a coherent decision. Just make it deliberately.

Can you add ACT Science later if you change your mind?

Not by itself, and this is the single most important thing on this page. ACT has never launched section retesting. It was announced, then postponed in 2020, and it does not exist. There is no mechanism to sit one section on its own.

So if you skip Science in September and a school you fall in love with in December wants it, your only route is registering for another full ACT and taking English, math and reading again alongside it. That is three hours, another fee, and another Saturday, to obtain a score you could have picked up for 40 minutes and a few dollars.

This asymmetry is the whole argument. Taking Science costs you 40 minutes now. Not taking it can cost you an entire test day later.

How is the ACT Science section scored?

Science is reported on the same 1 to 36 scale as every other section, and it stands alone on your report. It contains 34 scored items among 40 total (the other six are unscored field-test items you cannot identify) in 40 minutes, which is about 60 seconds per question.

For reference, the class of 2025 averaged 19.6 on Science, close to the 19.4 Composite average. Science is not a section where the national pool is unusually strong or weak.

Is the ACT Science section hard?

It is misnamed, which is what makes it feel hard. ACT Science tests almost no science content. It tests whether you can read a graph, follow an experimental design, and compare two scientists who disagree, at speed. Students who know a lot of biology often do worse than students who are simply fast and literal readers, because they answer from what they know rather than from what the passage shows.

The three passage types are worth naming, because they need different approaches:

• Data representation: charts and graphs. Go to the questions first, then hunt the figure for the specific value. Reading the passage carefully is a waste of your 60 seconds.
• Research summaries: described experiments. Identify the independent variable, the dependent variable and the control before you touch a question.
• Conflicting viewpoints: two or more scientists disagreeing. This is the one that rewards actual reading. Ask what each side would have to believe, then work out which side a new piece of evidence helps.

The good news for your prep budget: Science is the most learnable section on the test, because it is a procedure rather than a body of knowledge. Forty focused practice passages will move a Science score further than forty hours of chemistry review. Our ACT practice test drills Science separately from the Composite sections, precisely because it is now a separate score with its own logic.

Does the ACT Writing essay work the same way?

Writing has always been optional and remains so. It is unchanged by the enhanced ACT: 40 minutes, one prompt, scored 2 to 12 on its own scale, and never part of your Composite. ACT states the design, timing and scoring procedures are the same for both the legacy and enhanced tests.

The decision rule is the same as for Science, and simpler: a handful of schools still require or recommend it, and if any of them are on your list, take it. Adding Writing costs another 40 minutes. Taking both Science and Writing puts a full ACT at roughly 205 minutes of testing.

So what should you actually do?

Take Science unless you have a specific reason not to. It cannot hurt your Composite, it costs 40 minutes, and the alternative to changing your mind later is a whole extra test day. Then check your college list for whether anyone wants it, because that turns a default into a certainty.

And whatever you decide, practice on the current format. If your prep book has 60 math questions with five answer choices and a mandatory Science section, it was written for a test that no longer exists. Sorting out which of your study materials are stale is worth an hour of your time, in the same way that keeping any training program aligned with the current syllabus rather than last year's is the unglamorous work that decides whether the effort pays off at all. For the full picture on scoring, we have a breakdown of what counts as a good ACT score with the current percentile table.