The BASIS Independent Bothell ISEE is now the official entrance exam for the 2026–2027 admissions cycle, replacing the school's previous in-house test. This switch changes your entire prep strategy. The ISEE has its own format, scoring system, and one rule that catches families off guard every year: BASIS Independent Bothell accepts only your child's first submitted score — not the highest score across multiple sittings. I've watched students sit down underprepared because their families assumed they could retake and improve. At BASIS Bothell, that is not how it works. This guide covers everything you need to know before your child books a single test date.
BASIS Independent Bothell ISEE: Key Facts at a Glance
- Exam: ISEE (Independent School Entrance Exam) — Middle Level (grades 7–8 entry) or Upper Level (grades 9–12 entry)
- What it tests: Verbal Reasoning, Quantitative Reasoning, Reading Comprehension, Mathematics Achievement, plus an unscored Essay (30 minutes)
- Total testing time: 2 hours 40 minutes plus two 5-minute breaks (~3 hours total)
- Format: Four multiple-choice sections (4 answer choices each) + 1 handwritten essay; no calculator permitted
- No guessing penalty: Only correct answers count — no points deducted for wrong answers
- Score reporting: Scaled scores (760–940 per section), percentile ranks (1–99), and stanine scores (1–9)
- Application window: Opens August 1 annually; submission deadline November 19, completion deadline December 3 (2025–2026 cycle)
- On-campus ISEE proctoring: Once in Fall (Aug–Nov), twice in Winter (Dec–Mar) — for applicants only
- Critical rule: BASIS Independent Bothell considers only the chronologically earliest score submitted — prepare thoroughly before your first test date
- Regular Admissions score window: August 2025 – February 2026
- Enrollment deposit: $1,750 non-refundable upon signing Enrollment Agreement
Which ISEE Level Does Your Child Take for BASIS Independent Bothell Admissions?
The ISEE level depends on your child's current grade, not the grade they are entering. If your child is currently in grade 6 or 7 and applying to enter grade 7 or 8, they take the Middle Level ISEE. If your child is currently in grades 8 through 11 and applying to enter grades 9 through 12, they take the Upper Level ISEE.
Double-check this before you register through ERB or Prometric. Taking the wrong level uses up your child's one accepted score submission for BASIS Bothell — and there is no way to undo that. The two levels cover overlapping content but differ significantly in difficulty and question types, so your prep materials must match the correct level or you will have real gaps on test day.
BASIS Independent Bothell is actively expanding its grade offerings, with high school grades being added over the next several years. If you are applying for Upper Level entry, fewer seats and less historical data exist for those grade levels compared to the established middle school cohorts. Contact admissions directly to confirm which grades are open for 2026–2027 before starting your application. Also note that while the ISEE has a Lower Level for grades 2–3, this guide focuses specifically on Middle and Upper Level preparation, which covers the grades BASIS Bothell primarily enrolls.
The BASIS Independent Bothell Score Rule: Why Your First ISEE Test Date Is the Only One That Counts
This is the most important strategic detail in this guide. BASIS Independent Bothell accepts only the chronologically earliest set of ISEE scores submitted per applicant. The school does not consider your child's highest scores across multiple test sittings.
ERB policy does allow students to take the ISEE up to once per testing season — Fall, Winter, and Spring/Summer — for a maximum of three times per school year. Spring/Summer availability varies by testing center. But that retake flexibility means nothing for BASIS Bothell. Your child's first submission is the one admissions reviews, full stop.
Here is the detail that trips families up most: if your child takes the ISEE in August for a different school and those scores get submitted to BASIS before a stronger December sitting, the August scores are the ones BASIS evaluates. You need to coordinate your testing calendar carefully so your most prepared attempt is also the earliest one submitted to BASIS.
The Regular Admissions score window runs from August 2025 through February 2026. Scores from outside that window are not accepted for Regular Admissions. Aim to sit the ISEE once, fully prepared, before the November 19 application submission deadline — that is when seats start filling fast.
Families who understand this rule at the start of prep approach it completely differently. They build in 8–12 weeks of structured practice before booking any test date. Start there.
What ISEE Stanine Score Is Competitive for BASIS Independent Bothell?
BASIS Independent Bothell does not publish official cutoff scores. Based on how competitive private schools use the ISEE, a stanine of 7 or higher is generally considered strong. Stanines run from 1 to 9, and a stanine of 5 is exactly average. A stanine of 7 places your child in roughly the 77th–89th percentile range compared to students who applied to the same entry grade over the past three years — not all ISEE test-takers globally. That distinction matters: the comparison group is already a self-selected, academically motivated pool.
Given BASIS's explicit benchmark of outperforming Shanghai on PISA-style critical thinking assessments, admitted students are expected to perform at a high level from day one. A stanine of 4 or below in any section would raise real concerns. Targeting stanines of 7 or above in Quantitative Reasoning and Mathematics Achievement is a practical goal for competitive applicants. Scaled scores for each section fall between 760 and 940.
Verbal Reasoning and Reading Comprehension stanines matter too. BASIS's curriculum demands analytical reading and strong academic vocabulary across every subject, not just math. A balanced stanine profile across all four sections is stronger than one exceptional math score paired with weak verbal results.
- Aim for stanine 7 or above in all four sections
- Stanines of 5–6 may still be considered alongside strong recommendations and a compelling interview — but they present more risk given BASIS Bothell's academic expectations
- Check scaled scores too: each section ranges from 760 to 940, and admissions sees the full picture
- Book your test date only after your practice scores consistently hit your target range
ISEE Prep for BASIS Independent Bothell: Why STEM Critical Thinking Practice Makes the Difference
The ISEE's Quantitative Reasoning section is the one most students underestimate. It does not test memorized formulas. It tests mathematical logic, quantitative comparisons, and multi-step abstract reasoning — without a calculator. I've seen students who drilled arithmetic for weeks walk into this section and stall completely on the reasoning questions, because the two skills are genuinely different.
BASIS's curriculum is built around the type of analytical thinking measured by PISA-style assessments. Admitted students need to work through unfamiliar problems under time pressure from their very first week of class. The ISEE Quantitative Reasoning section is a direct preview of that expectation.
Mathematics Achievement tests grade-level content your child should already know — fractions, algebra foundations, geometry basics, and number properties depending on level. This section responds well to structured content review. Both sections together account for half the multiple-choice questions on the exam.
Students who switch from rote formula drills to logic-focused critical thinking practice can improve their Quantitative Reasoning stanines by two full points. The difference is the type of practice, not just the hours. STEM Critical Thinking practice tests that require logical deduction and multi-step reasoning — the kind available at stemcriticalthinking.com — are built specifically for this gap.
The BASIS Independent Bothell ISEE Essay: What Admissions Actually Looks For
The ISEE essay is not scored by ERB. It is, however, sent directly to BASIS Independent Bothell, where admissions staff read it as a writing sample. For a school that holds middle and high school students to AP-level writing standards, a weak essay signals a mismatch — even when test scores are strong.
Students have 30 minutes to complete a handwritten response to a grade-appropriate prompt. BASIS admissions is looking for organization, clarity, developed reasoning, and a sense that your child can construct an argument rather than just restate the question. A focused thesis, two or three specific supporting points, and a clean conclusion — all written by hand in under 30 minutes — is exactly what a strong BASIS applicant produces.
Timed essay practice before test day is not optional for BASIS Bothell applicants. Build the habit of writing a clear thesis first, then supporting it with specific details, then wrapping up in two or three sentences. Aim to finish the essay in 25 minutes and spend the last five reviewing. Essay Writing practice tests at stemcriticalthinking.com match this exact 30-minute format and help 8th and 9th graders build the writing stamina they need before test day.
BASIS Independent Bothell ISEE Test Dates, Application Deadlines, and the Full Admissions Timeline
BASIS Independent Bothell proctors the ISEE on campus for applicants — once during the Fall season (August through November) and twice during the Winter season (December through March). These dates are available only to students who have already submitted an application. You can also register for the ISEE at any ERB or Prometric testing center year-round for more scheduling flexibility.
The 2025–2026 application cycle opens August 1. The submission deadline is November 19, and the completion deadline is December 3. Decisions roll out after your file is complete. Early Admissions — reserved for siblings of current students — is reviewed first. The commitment deadline requires a signed Enrollment Agreement and a $1,750 non-refundable deposit.
Seats fill quickly at popular grade levels. Earlier applications get earlier decisions, and earlier decisions give your family more time to plan. If your target grade level is competitive, aim to submit well before November 19 rather than in the final days of the window.
Beyond the ISEE, BASIS Bothell requires current-year and prior two-year transcripts, one to two recommendation letters from math and English teachers, a Virtual Family Meeting, and a student interview or virtual play date depending on grade level.
Frequently Asked Questions: BASIS Independent Bothell ISEE Admissions 2026–2027
Q: Did BASIS Independent Bothell change its entrance exam?
A: Yes. Starting with the 2026–2027 admissions cycle, BASIS Independent Bothell replaced its in-house entrance exam with the ISEE for middle and high school entry grades. Any prep materials built around the old proprietary test are now outdated — the question types, scoring system, and strategy are completely different. The ISEE covers Verbal Reasoning, Quantitative Reasoning, Reading Comprehension, Mathematics Achievement, and an unscored essay. ERB administers and scores the multiple-choice sections, but the essay is sent directly to BASIS admissions staff for review. If someone tries to sell you old BASIS prep materials, ask specifically whether they are built for the ISEE.
Q: What ISEE level does my child take for BASIS Independent Bothell?
A: Your child's current grade determines the level, not the grade they are entering. Students currently in grade 6 or 7 applying to enter grades 7 or 8 take the Middle Level ISEE. Students currently in grades 8 through 11 applying to enter grades 9 through 12 take the Upper Level ISEE. Confirm this with BASIS admissions before registering with ERB. Taking the wrong level forfeits your one accepted score submission. The Upper Level includes more advanced algebra, data analysis, and complex verbal reasoning than the Middle Level, so prep timelines and materials are different — do not mix them up.
Q: Why does BASIS Independent Bothell only accept the earliest ISEE score?
A: BASIS reviews the first set of ISEE scores submitted per applicant, not the highest scores from multiple attempts. Retaking the test to improve your score does not help here. The practical implication most families miss: if your child tests in August for a different school and those scores reach BASIS before a stronger December attempt, August is what BASIS sees. Map out your child's full testing calendar before booking any date, and make sure the first submission to BASIS is from your strongest, best-prepared sitting.
Q: What sections of the ISEE should my child prioritize for BASIS Independent Bothell?
A: Quantitative Reasoning and Mathematics Achievement are the two sections most directly tied to BASIS Bothell's STEM-intensive curriculum. Quantitative Reasoning tests logical deduction and multi-step reasoning without a calculator — not memorized formulas. Mathematics Achievement tests grade-level content. Together they make up half the multiple-choice exam. That said, Verbal Reasoning and Reading Comprehension still affect your overall stanine profile, and BASIS evaluates the full picture. Spend the most time on Quantitative Reasoning if your child has any gaps in math logic, but do not neglect the verbal sections.
Q: What ISEE stanine score does my child need to be competitive at BASIS Independent Bothell?
A: BASIS does not publish official cutoffs. At competitive private schools using the ISEE, stanines of 7 or above are considered strong. A stanine of 5 is exactly average, and stanines are normed against students who applied to the same entry grade over the past three years — not the full global ISEE population. That is already a high-achieving comparison group. Given how rigorous BASIS Bothell's program is from day one, a stanine of 4 or below in any section would be a red flag. Target 7 or above across all four sections and use practice tests to check your child's score range before booking a test date.
Q: Does BASIS Independent Bothell actually read the ISEE essay if it is not scored?
A: Yes — BASIS admissions staff receive the essay directly from ERB and read it as a holistic writing sample. Students have 30 minutes to write by hand in response to a grade-appropriate prompt. Because BASIS's academic program requires structured analytical writing at an AP level, admissions uses the essay to see whether your child can organize thoughts, develop an argument, and write clearly under time pressure. A strong essay will not cancel out weak test scores, but a disorganized essay can introduce real doubt about readiness even when scores are solid. Practice timed writing before test day — it is a skill, and it responds to repetition.
Q: Can my child take the ISEE at the BASIS Independent Bothell campus?
A: Yes, but only after submitting an application. BASIS proctors on-campus ISEE sessions once in the Fall (August through November) and twice in the Winter (December through March), exclusively for their applicant pool. Families who have not yet applied must use an external ERB or Prometric center. One practical upside to the on-campus option: your child sees the school environment before the admissions decision comes through, which can make the Virtual Family Meeting and student interview feel less unfamiliar.
Q: Which teacher recommendation letters does BASIS Independent Bothell require, and how should we ask for them?
A: BASIS requires one to two recommendation letters from core subject teachers — specifically math and English. Pick teachers from the current or most recent year who have watched your child work through genuinely difficult material. Give each teacher at least four weeks of lead time. When you ask, share a quick note about what BASIS values: intellectual curiosity, persistence, and initiative with hard problems. The letters that actually help in admissions name a specific moment — a time your child caught a mistake and fixed it, asked a question that pushed the class further, or tackled something hard without being prompted. Generic praise does not give admissions staff anything to work with.
Start Your BASIS Independent Bothell ISEE Prep Today
Your child gets one shot at the BASIS Independent Bothell ISEE — that first submitted score is the one that counts. The students who score stanines of 7 and above on ISEE Quantitative Reasoning are the ones who practiced logical, multi-step problem solving before test day. Not formula drills. Not generic math worksheets. Actual reasoning practice that mirrors what the ISEE tests.
Our STEM Critical Thinking Practice Tests at stemcriticalthinking.com are built for 8th–10th graders and designed to match the abstract reasoning demands of the ISEE Quantitative Reasoning section. They build the same analytical habits BASIS Independent Bothell expects its students to use from their first week of class.
And because BASIS admissions reads every ISEE essay, a clear and organized writing sample matters. Our Essay Writing Practice Tests give your child timed essay practice in the exact 30-minute format they will face on test day — with structured feedback to help them improve before it counts.
Start both practice tracks at least 8 weeks before your child's planned ISEE test date. Seats at BASIS Independent Bothell fill quickly, and preparation time is the one variable entirely in your control.
Try a STEM Critical Thinking Practice Test → | Try an Essay Writing Practice Test →
