The ACT Science Section Is Now Optional: How to Decide Before You Register for September

The single biggest structural change in the enhanced ACT is one that many students still haven’t fully processed: the Science section is no longer required. When you register for the September 19 test date, you’ll face a checkbox that previous generations of ACT takers never saw — take Science, or skip it entirely. Your Composite score now comes from English, Math, and Reading alone, and Science, if you choose it, is reported as a separate score alongside them.

That checkbox deserves more thought than most students give it. The right answer depends on where you’re applying, what you intend to study, how you’ve historically performed on the section, and how much prep time you have left this summer. This guide walks through each of those factors so you can make the call deliberately — before the registration deadline forces it.

What Actually Changed

Under the enhanced ACT format, the core test consists of English, Math, and Reading. These three sections produce your Composite score on the familiar 1–36 scale. Science is now an add-on: you opt in during registration, sit for it after the core sections, and receive a separate Science score that does not affect your Composite.

This is a real departure from the old model, where Science was one of four equal contributors to the Composite. A student who historically lost two or three Composite points to a weak Science section now has a structural advantage: those points simply no longer count against the headline number. Conversely, a student whose Science score routinely led their other sections has lost a built-in boost.

Two practical details matter here. First, opting into Science lengthens your test day — you’ll sit for an additional 40-question section after completing the core test. Second, colleges will see your Science score if you take it and submit that test date’s results. There is no picking and choosing after the fact within a single administration.

Who Should Take Science

The decision is not close for certain groups of students.

Prospective STEM majors should take it. If you’re applying to engineering, pre-med tracks, computer science, or natural science programs, a strong Science score is corroborating evidence for the story your application tells. Admissions readers at selective STEM programs are accustomed to seeing the section, and its absence from an otherwise science-heavy application invites a question you don’t want asked. If your practice Science scores sit at or above your Composite, the section is close to free upside.

Students targeting scholarship programs with legacy score requirements should check the fine print. Some state scholarship programs, honors colleges, and NCAA-related benchmarks were written in the era of the four-section Composite. Many have updated their language; some have not. If a scholarship you’re counting on specifies score requirements, confirm with the administering body whether they expect a Science score before you decide to skip it.

Students applying to colleges that recommend all sections should lean toward taking it. College policies on the optional Science section are still settling. A handful of institutions have stated preferences; most accept the core Composite without comment. The reliable move is to check the standardized testing page of every college on your list — the same list you should be finalizing this month — and let the most demanding school’s policy set your floor.

Who Should Skip It

Students whose Science score consistently drags below their other sections. If your practice tests show English, Math, and Reading averaging 29 while Science lands at 24, the enhanced format is offering you a gift: a Composite that reflects your strongest three sections. Unless a school on your list asks for Science, there’s little reason to attach a below-profile number to your record.

Students with limited prep runway who need every hour for the core. Between now and September 19, your prep hours are finite. The Science section rewards a specific skill — rapid interpretation of charts, tables, and conflicting-viewpoints passages — that takes dedicated practice to sharpen. If adding Science prep would dilute your work on the three sections that actually form your Composite, the trade is rarely worth it for a non-STEM applicant.

Students managing test-day stamina concerns. The enhanced core test is shorter than the old four-section marathon, and many students perform better for it. Adding Science extends the day and reintroduces the late-test fatigue the redesign relieved. If you’ve historically faded in the final section, skipping Science protects the scores that matter most.

The Gray Zone: Undecided Majors and Balanced Scorers

Most students don’t fall neatly into either camp. If you’re undecided on a major and your Science practice scores roughly match your other sections, here is a reasonable default: take it once. A Science score in line with your Composite costs you nothing, keeps every door open — including the STEM programs you might discover an interest in during senior year — and spares you a second test date if a college on your evolving list turns out to want it.

The reverse default applies if you’ve already taken the ACT with Science and posted a solid score: you don’t need to repeat the section. A prior Science score remains reportable, and you can sit the core-only test on September 19 to focus entirely on raising your Composite.

How This Changes Your Prep Between Now and September

If you decide to skip Science, restructure your remaining weeks immediately. Every practice block you had penciled in for data-representation drills now goes to your weakest core section. For most students that’s either Reading pacing or the mid-difficulty Math band — be honest about which, and let your last two full practice tests confirm the reallocation is working.

If you decide to take Science, treat it as a fourth subject with its own dedicated practice, not an afterthought. The section’s format rewards familiarity more than content knowledge: nearly everything you need is in the passages, and your job is speed. Two timed Science sections per week between now and test day, with error review focused on question types rather than topics, is enough for most students to hold or improve their historical level.

Either way, your full-length practice tests should mirror your real test-day configuration. If you’re taking Science, practice with it in position — after the core sections, when you’re tired. If you’re skipping it, stop simulating it; practice the actual shape of your day.

Registration Logistics for September

The decision has a deadline. Science opt-in happens at registration, so settle the question before you sign up rather than defaulting your way through the checkbox. The standard registration deadline for the September test date typically falls in mid-August, with a late-registration window (and fee) extending a couple of weeks beyond. If you’re reading this in August, the clean move is to finalize your college list’s testing requirements this week, run one timed Science section to check where you stand, and register with a deliberate choice.

If you’ve already registered and are having second thoughts, ACT allows changes to your registration for a fee up to the late deadline — check your MyACT account for the specific cutoff attached to your administration.

A Simple Decision Checklist

Run through these five questions in order. The first one that produces a definitive answer decides for you.

1. Does any college or scholarship program on your list require or explicitly recommend the Science section? If yes, take it.
2. Are you applying to STEM programs anywhere on your list? If yes, take it.
3. Do you already have a reportable Science score you’re satisfied with? If yes, skip it this time.
4. Is your practice Science score two or more points below your practice Composite? If yes, skip it.
5. Still undecided? Take it once — matching scores cost nothing and preserve options.

What About Superscoring?

One wrinkle worth understanding before you finalize the decision: superscoring. Colleges that superscore the ACT combine your best section scores across multiple test dates into a recalculated Composite. Under the enhanced format, that math runs on English, Math, and Reading — which means a weak Science outing from an earlier administration no longer weighs down the number superscoring produces. If you took the old four-section ACT in the past and Science was your soft spot, a strong core-only sitting in September can lift your superscore more efficiently than it could under the old rules.

The flip side: if Science was your standout section on a previous attempt, that score still exists and can still be reported alongside your new results. You don’t need to re-earn it. This is another reason repeat testers with a solid Science score on file should usually register core-only and pour everything into the three sections that move the Composite.

The Bottom Line

The optional Science section is the enhanced ACT’s most consequential fork, and it rewards students who decide on purpose. Match the choice to your college list and your data, not to habit or rumor. A STEM applicant with strong practice scores should welcome the section as free evidence; a humanities applicant fighting for Reading points should welcome its absence as free focus. Make the call this week, register cleanly for September 19, and spend the remaining weeks preparing for exactly the test you’ve chosen to take.