Historic Drop in PISA Reading Scores Meets Program-Reported Gains: What Educators Should Make of New Lexia Data

The OECD’s PISA 2025 results show the largest-ever drop in reading performance among 15-year-olds. At the same time, Lexia’s 2025–26 data for K–12 students using Core5 Reading and PowerUp Literacy suggest substantial progress when those programs are implemented with fidelity. Educators and policymakers face the task of reconciling broad international declines with program-level improvement claims and deciding how best to invest in literacy recovery.

By Where Should I Learn Editorial · 2026-09-27

The Organisation for Economic Co-operation and Development’s PISA 2025 assessment delivered stark news for education systems: average reading performance among 15-year-olds across OECD countries fell 14 points between 2022 and 2025, the largest decline recorded between two cycles of the exam. The finding has prompted renewed concern among educators and policymakers about reading achievement and the long-term effects of recent disruptions on adolescent literacy.

Against that international backdrop, a program-level report released by Lexia, a brand of Cambium Learning Group, offers a contrasting narrative. Lexia’s newly released 2025–26 data indicate that K–12 students who used Lexia Core5 Reading and Lexia PowerUp Literacy with fidelity “made substantial literacy progress,” and that progress included students who began the school year multiple grade levels behind, according to the company’s statement. The company positions these findings as an encouraging counterpoint to the broad declines captured by PISA.

Readers should note the difference in scale and scope between the two sources. PISA is an international survey focusing on 15-year-olds and designed to compare system-level performance across countries on a common assessment. Lexia’s results pertain to students in K–12 classrooms who used two specific literacy programs during the 2025–26 school year. Because the samples, age ranges, and assessment methods differ, the two data sets are not directly comparable; they instead illuminate different aspects of the literacy landscape.

The Lexia report emphasizes the role of implementation fidelity: the claim of substantial progress applies to classrooms and schools that delivered Core5 Reading and PowerUp Literacy as intended. Fidelity typically refers to consistent use of program components—frequency, duration, and adherence to instructional protocols—plus teacher training and progress monitoring. Research on curriculum and intervention implementation generally shows that fidelity is a key mediator of student outcomes, a point that Lexia’s presentation echoes without providing detailed, independent metrics in the released summary.

Implementation fidelity is also where many districts run into practical challenges. Schools can adopt evidence-based materials but struggle to sustain them without ongoing professional development, data systems that flag students needing more support, and staffing arrangements that enable small-group or intensive instruction. That practical gap helps explain why system-level assessments like PISA can decline even as some classrooms or schools show gains with targeted tools.

The contrast between international declines and program-reported improvements raises questions about scale. Even if a program produces meaningful gains for participating students, the size of that participant pool and the conditions under which the gains were realized determine whether such gains can blunt or reverse broader downward trends. Lexia’s release highlights success among users of its products, but it does not, in the material provided, document how widely those conditions were met across districts or how gains translate into systemwide shifts on assessments like PISA.

Another consideration is the nature of the evidence. Program-reported outcomes are an important piece of the picture, particularly when they include disaggregated results for students far behind grade level. At the same time, independent evaluations, peer-reviewed studies, and replication across diverse contexts provide stronger confirmation that a program produces generalizable effects. For policymakers and district leaders weighing investments, comparing vendor data with external research and local pilot results is a prudent approach.

Policy implications follow from these distinctions. The PISA decline underscores the urgency of investing in literacy at multiple grade levels, not only in early grades but through adolescence. Lexia’s data underscore that targeted, implemented-with-fidelity interventions can help students who start the year behind. Together, these signals suggest a two-pronged response: strengthen prevention and grade-level instruction broadly, while expanding targeted interventions and the supports—training, staffing, data systems—that allow fidelity at scale.

District leaders contemplating specific tools should also build evaluation into adoption plans. That means setting clear implementation benchmarks, routinely monitoring student progress, and committing to third-party evaluation when possible. Successful classroom practice often depends on alignment: standards, assessment systems, professional learning, and instructional materials must work in concert to move large numbers of students.

The PISA 2025 results make clear that reading achievement in many systems is under strain. The Lexia 2025–26 findings, as reported by the company, present encouraging evidence that progress is possible for students when specific programs are delivered consistently and with appropriate supports. The larger task for education leaders is to translate program-level gains into sustained, systemwide improvement—an outcome that will require careful implementation, rigorous evaluation, and attention to the real-world constraints schools face.