Achievement test · K-12 · Updated November 3, 2026

Iowa Assessments (ITBS), explained for parents

Which level your child takes, what is on it, how long it runs, and what the numbers on the report mean. Taken from Riverside Insights' own brochure and score guides.

What is the Iowa Assessments?

A nationally normed achievement test for kindergarten through grade 12, published by Riverside Insights. It measures what a child has learned in reading, language, math, and often science and social studies, and compares the result with students in the same grade across the country. The University of Iowa's testing program wrote the first version in 1935 as the Iowa Tests of Basic Skills (ITBS); it was later renamed.

It is not Iowa's state test. Iowa public schools give a separate state assessment; see our Iowa state test guide for that one.

Who gives it, and why

Schools and districts

On paper or online, often in fall to plan teaching and again in spring to measure growth. Forms E, F and G are built to the same blueprint, so a school can test with one form in fall and another in spring.

Private and Catholic schools

Riverside offers private and Catholic school norms on request, so a report can compare your child with private school students as well as the nation.

Gifted programs

Riverside publishes the CogAT too, and its online Multimeasure Student Roster can show both scores side by side: the CogAT measures reasoning, the Iowa measures what was learned. South Carolina gives both to every grade 2 student (SC Department of Education). Ohio's 2025-26 approved list includes the Iowa Assessments for gifted prescreening in specific academic ability (grades 1 to 8) and for gifted identification (Ohio approval form).

Which level does each grade take?

The test comes in levels, not grades. This is Riverside's recommended level for each grade and testing season.

Grade	Fall	Midyear	Spring
K	not listed	5	5 to 6
1	6	6 to 7	7
2	7	8	8
3	8 to 9	9	9
4	10	10	10
5	11	11	11
6	12	12	12
7	13	13	13
8	14	14	14
9	14 to 15	14 to 15	14 to 15
10	16	16	16
11	17/18	17/18	17/18
12	17/18	17/18	17/18

Source: Riverside Iowa Assessments Overview Brochure.

What is on the test, grades 3 to 8

Levels 9 to 14 cover grades 3 to 8. The number of questions grows with each level, but the time for each subtest stays the same.

Test	Questions (Level 9 to 14)	Minutes
Reading *	41 to 46	30 + 30
Written Expression *	35 to 48	40
Mathematics *	50 to 75	30 + 30
Vocabulary *	29 to 42	15
Spelling *	24 to 35	10
Capitalization *	20 to 29	10
Punctuation *	20 to 29	10
Computation *	25 to 32	20
Science	30 to 43	35
Social Studies	30 to 43	35

* Part of the Core battery. Reading and Mathematics are given in two parts. Level 9 (grade 3) also has Word Analysis (33 questions) and a Listening test read aloud by the teacher (28 questions).

Grades 4 to 8 (Levels 10 to 14)

About 4 hours 55 minutes for the Complete battery, 3 hours 45 minutes for the Core.

Grade 3 (Level 9)

About 5 hours 40 minutes for the Complete battery, 4 hours 30 minutes for the Core.

Kindergarten to grade 2 (Levels 5 to 8) have Vocabulary, Word Analysis, Listening, Language, Mathematics and Reading. Level 6 splits Reading into two parts. Levels 7 and 8 add Computation, Science and Social Studies, and split both Reading and Mathematics into two parts.

The scores on the report

These definitions follow Riverside's score descriptions, in plain words.

National Percentile Rank (NPR)

The share of students in the same grade nationally who scored the same or lower. 50 is average. It is not the percent of questions right, and its steps are uneven: moving from the 90th to the 95th takes far more than moving from the 50th to the 55th.

Percentile Rank (PR)

The same idea as the NPR, against whichever group the line names: local percentiles compare with your district, and private school percentiles with private school students.

Stanine

The same result in nine broad bands, 1 to 9, averaging 5. Small differences that mean little do not change the stanine.

Grade Equivalent (GE)

Grade and month, so 4.6 means the score a typical student gets in the sixth month of grade 4. A third grader with a GE of 5.2 did very well on the third grade test; it does not mean they know fifth grade content.

Standard Score (SS)

A point on one long scale from kindergarten through high school. Because every level shares the scale, the SS is the score to compare from year to year to see growth.

Normal Curve Equivalent (NCE)

Runs from 1 to 99 with 50 as average, like a percentile, but in equal steps, so schools can average it. You can usually skip it.

Percent Correct (%C)

Questions right divided by questions asked. On skill lines it shows which skills went well and which did not, next to the national average for that skill.

Lexile and Quantile

A reading measure for choosing books at the right difficulty, and a math measure for which skills your child is ready for next.

College readiness (Levels 12 and up)

From grade 6, scores can be mapped to ACT benchmarks and shown as a predicted ACT or SAT range.

Percentile and stanine together, roughly

Stanine	NPR	What it means
9	96 to 99	Top 4%
8	89 to 95	Well above average
7	77 to 88	Above average
4 to 6	23 to 76	The middle 54% of students
2 to 3	4 to 22	Below average
1	1 to 3	Bottom 4%

Stanine bands hold 4, 7, 12, 17, 20, 17, 12, 7 and 4 percent of students, which gives the percentile ranges above; published tables can differ by a point at the edges. Your child's report prints both numbers; go by those.

Check the norms year

A percentile depends on which students it is compared with. Riverside's scoring instructions, updated in August 2025, score Forms E, F and G against 2024 national norms by default; a school can still ask for the older 2017 norms. The norms year is printed near the top of the report. If last year's report used 2017 norms and this year's uses 2024, part of any change in percentile can come from the new comparison group rather than from your child. Source: Riverside, 2024 norms.

Questions parents ask

Is the ITBS the same as the Iowa Assessments?

Yes. The University of Iowa's testing program wrote the first Iowa Tests of Basic Skills in 1935, and the test is now called the Iowa Assessments. It is published by Riverside Insights, the same company that publishes the CogAT.

Is the Iowa Assessments the same as Iowa's state test?

No. Iowa public schools give the state's own summative assessment (formerly called ISASP) for accountability. The Iowa Assessments is a separate, nationally normed test that schools in any state can choose to give.

What is a good Iowa Assessments score?

A National Percentile Rank (NPR) of 50 is exactly average: your child scored the same as or higher than half of students in the same grade nationally. Stanines 4 to 6 (roughly NPR 23 to 76) are the average band, and stanines 7 to 9 (NPR 77 and up) are above average. Gifted programs and schools set their own cut-offs.

What does a grade equivalent of 5.2 mean for a third grader?

It means your child scored the way a typical student in the second month of grade 5 would score on that same third grade test. It is a strong result, but it does not mean your child has learned fifth grade content: the test they took only covered third grade material.

How long is the Iowa Assessments?

For grades 4 to 8 (Levels 10 to 14), Riverside lists about 4 hours 55 minutes of working time for the Complete battery and 3 hours 45 minutes for the Core battery. The Level 9 (grade 3) Complete battery is about 5 hours 40 minutes, because it also has Word Analysis and Listening.

Which norms are on my child's report?

Riverside's scoring instructions, updated in August 2025, score Forms E, F and G with 2024 national norms unless the school asks for the older 2017 norms. The report shows the norms year near the top. Percentiles from the two norm years are not directly comparable.

What is the difference between the Complete and Core battery?

From grade 3 up, the Core battery is Reading, Written Expression, Mathematics, Computation, Vocabulary, Spelling, Capitalization and Punctuation; at Level 9 (grade 3) it also includes Word Analysis and Listening. The Complete battery adds Science and Social Studies. A school can also give a shorter Survey battery or single subjects.

Can my child prepare for the Iowa Assessments?

The test measures what was taught, so the best preparation is solid grade-level skills: reading stamina, math facts and multi-step word problems, spelling and punctuation. A short look at the question formats beforehand can help a child feel calmer; last-minute cramming is less useful than steady grade-level practice.

Sources

Checked November 3, 2026.

Find the skills behind the score

The Iowa Assessments tests grade-level skills. Our diagnostic shows which of your child's grade-level skills are solid and which need work.

Start the diagnostic →Grade-level guides CogAT scores Gifted testing dates