AOS vs AET vs TJ: Which STEM High School Program Fits Your Child?
Loudoun 8th graders can apply to three selective STEM programs: the Academy of Science and the Academy of Engineering and Technology at the Academies of Loudoun, and Thomas Jefferson High School for Science and Technology. Here is how they differ, side by side.
Talk It Through With UsSide by side
| AOS | AET | TJ | |
|---|---|---|---|
| Where | Academies of Loudoun campus, Leesburg | Academies of Loudoun campus, Leesburg | 6560 Braddock Road, Alexandria (Fairfax County) |
| Schedule | Every other school day at the Academies; other days at the home high school | Every other school day at the Academies; other days at the home high school | Full-time, every day |
| Focus | Advanced math and science; mentored science research in grades 10, 11 and 12 | Engineering or computer systems pathways, each ending in junior and senior research; entrepreneurship pathway | Broad STEM high school; integrated 9th grade program; every senior completes a research program, typically in one of nine labs |
| Run by | Loudoun County Public Schools | Loudoun County Public Schools | Fairfax County Public Schools (Governor's School) |
| Who can apply | LCPS 8th graders in Algebra I or higher, C or better in math and science | LCPS 8th graders in Algebra I or higher, C or better in math and science | 8th graders from participating divisions incl. Loudoun; unweighted GPA 3.5+, Algebra I, honors science |
| How students are selected | STEM thinking-skills test, timed writing assessment and grades; blind review | Same tests as AOS (separate application) | Core GPA, Student Portrait Sheet, Problem-Solving Essay, experience factors; 1.5% of seats per middle school |
| 2026–27 key date | Test: Nov 12, 2026 | Test: Nov 12, 2026 | Essay sitting: Jan 9, 2027 |
| Decisions | Spring 2027 (typically March) | Spring 2027 (typically March) | Apr 30, 2027 |
| Cost | Free (LCPS program) | Free (LCPS program) | Free for Loudoun students (LCPS pays tuition and provides buses) |
Why the Academies, why TJ
The Academies of Loudoun may suit students who…
- want specialized STEM classes while keeping their home high school, friends, clubs and sports
- prefer a shorter commute within Loudoun
- know their direction: science research (AOS) or engineering and computing (AET)
TJ may suit students who…
- want a full-time school where every classmate is STEM-driven
- are ready for a daily bus ride to Alexandria
- want a broad mix of research labs and electives across many STEM fields
All three are tuition-free public programs with real research, and admission to any of them is a strong start. The right choice depends on the student, not on which name sounds more impressive.
Questions to ask at home
- Does my child want to stay connected to their home high school, or start fresh somewhere new?
- How does my child feel about a long daily commute?
- Is their interest focused (science research, engineering, computing) or broad?
- Does my child do their best work surrounded entirely by high-achieving STEM peers, or with a mix?
How the admissions differ
The Academies of Loudoun use a test: a STEM thinking-skills test plus a timed writing assessment. Read the Academies admissions guide.
TJ uses writing and grades: a Student Portrait Sheet, a math or science Problem-Solving Essay and core GPA, with no entrance exam. Read the TJ admissions guide.
The common thread is reasoning that a student can explain clearly. That is why our program teaches STEM and writing side by side, one hour each, in every class.
Questions parents ask
Can my child apply to both the Academies and TJ?+
Yes. The Academies test is in November and TJ's essay sitting is in January, with separate applications, so a student can apply to both.
What if my child is admitted to both?+
Families choose one. Academies offers come out in spring and TJ's final decisions by April 30. In the 2023 cycle, Academies offers could be accepted or declined between March and August; check the current LCPS deadline when offers arrive.
Does preparing for one help with the other?+
Yes. Both reward strong algebra, clear reasoning and the ability to explain thinking in writing. Our year-long program alternates Academies and TJ essay prompts for that reason.
Which is harder to get into?+
Both are selective, and rates change each year. TJ offered 550 seats to 2,605 applicants in 2025 (about 21%). We have not found a current official Academies acceptance rate from LCPS.
Preparing for one or both?
Our year-long AOS and AET program starts in 7th grade, and our winter TJ class covers the Portrait Sheet and Problem-Solving Essay.
Sources
Last checked November 1, 2026. Admissions details are set by LCPS and FCPS and can change; always confirm on their official pages.