Tangipahoa Kindergarten DIBELS Results: 24% to 68% at Benchmark

Tangipahoa Parish School System implemented Once with nearly every kindergarten student across its 14 elementary schools during the 2025-26 school year. A new LXD Research study reports substantial gains on DIBELS 8th Edition, while making an important limitation clear: without a comparison group, the results are descriptive and correlational, not proof that Once caused the gains.

The study included 1,263 kindergartners with complete fall and spring DIBELS data, representing 99% of the district’s kindergarten cohort. Of the students in the study, 82% were economically disadvantaged, 13% were students with disabilities, and 6% were multilingual learners.

Three findings stand out

First, the percentage of kindergartners reading at or above benchmark rose from 24% in the fall to 68% in the spring. Among the 962 students who began below or well below benchmark, 58% reached benchmark by spring.

Second, the median student’s standing relative to national DIBELS norms rose from the 43rd percentile in fall to the 61st percentile in spring. A cohort making the same growth as the national norm group would be expected to remain at roughly the same percentile. Most of Tangipahoa’s measured percentile movement occurred between fall and midyear, with more modest growth between midyear and spring.

Third, students who received more Once instructional time tended to have stronger spring outcomes. Across four instructional-hour groups, the share of students reaching benchmark rose from 39% in the lowest-hours group to 86% in the highest-hours group. The relationship remained statistically significant after the researchers accounted for fall DIBELS scores, school, and demographic characteristics.

Delivery and school-level variation matter

The median student completed about 100 Once sessions, equal to 17.4 hours of instruction. The district delivered a median of 80% of scheduled sessions, a high rate for an implementation reaching almost an entire district cohort.

Results also varied substantially across the 14 schools. Median percentile changes ranged from -7 to +34 points. The report identifies scheduling, staffing stability, and implementation oversight as possible contributors.

For district leaders, this may be the most actionable finding. Program adoption is only the first step. Leaders also need a clear delivery target, regular monitoring, and support for schools where implementation falls behind.

Why kindergarten deserves attention

Districts deciding how to divide limited intervention resources may ask whether kindergarten should take priority over later grades. A separate 2026 NWEA study of more than 400,000 students offers a strong reason to act early.

Among students who entered kindergarten in the bottom 20% for reading, 13.9% reached third-grade reading proficiency. For students still in the bottom 20% at the start of first grade, the rate fell to 5.8%. By the end of first grade, it was 2.5%.

These results do not mean a child’s future is fixed in kindergarten. They show that early screening and support give schools more time to change a student’s path before third grade.

Read the full study

The Tangipahoa findings are encouraging, especially given the scale of the implementation. They should still be read with the study’s limitations in mind. There was no untreated comparison group, DIBELS was administered by school staff, and the reported usage data may include some instruction delivered after spring testing.

Read the full LXD Research study and contact Once if you want to discuss what a district-wide early reading implementation could look like in your schools.