Inside the Updated Dyslexia Definition: What District Leaders Need to Know

For the first time in more than twenty years, the International Dyslexia Association (IDA) has released an updated dyslexia definition that reflects major advances in reading research, assessment, and language development. This revision replaces the long-standing 2002 version and better represents what district leaders and school teams observe every day in classrooms.

The updated dyslexia definition will influence how districts:

• Identify and support students

• Revise dyslexia guidance and policy

• Design MTSS and intervention frameworks

• Train and coach instructional staff

• Strengthen early childhood language development

• Communicate clearly with families

It will also shape curriculum decisions, staffing allocations, data systems, and professional learning priorities as districts determine whether current practices reflect the broader understanding of dyslexia contained in this new definition.

District leaders should also examine how the updated dyslexia definition aligns with state legislation. Because states vary in policy language, crosswalking district guidance with both state requirements and the IDA definition is essential for clarity and compliance.

Definitions shape systems. This one supports more coherent, research-aligned screening, instruction, evaluation, and intervention across the district.

The Updated IDA Definition of Dyslexia

The updated IDA definition of dyslexia reflects more than two decades of scientific progress. It provides a fuller, more accurate description of what dyslexia is, how it develops, and how it affects students across grade levels. District leaders can use this definition to align screening practices, instructional decisions, and MTSS structures with the most current understanding of reading development. The complete definition is included below for reference.

“Dyslexia is a specific learning disability characterized by difficulties in word reading and/or spelling that involve accuracy, speed, or both and vary depending on the orthography. These difficulties occur along a continuum of severity and persist even with instruction that is effective for the individual’s peers. The causes of dyslexia are complex and involve combinations of genetic, neurobiological, and environmental influences that interact throughout development. Underlying difficulties with phonological and morphological processing are common but not universal, and early oral language weaknesses often foreshadow literacy challenges. Secondary consequences include reading comprehension problems and reduced reading and writing experience that can impede growth in language, knowledge, written expression, and overall academic achievement. Psychological well-being and employment opportunities also may be affected. Although identification and targeted instruction are important at any age, language and literacy support before and during the early years of education is particularly effective.”

This updated definition offers a comprehensive, research-aligned understanding of dyslexia. For district leaders, it establishes a foundation for reviewing current systems, identifying gaps, and ensuring that screening, instruction, and intervention practices reflect the best available science. The next section outlines the most significant changes and what they mean for district-level decision-making.

What Has Changed in the Updated Dyslexia Definition

Below are the eight major shifts introduced in the updated dyslexia definition. These changes expand the field’s understanding of dyslexia and shape how districts design systems for early identification, instruction, staffing, data use, and communication.

1. Dyslexia Is Described as a Continuum

The updated dyslexia definition recognizes that dyslexia varies in severity. Students may present with mild, moderate, or significant challenges. This supports more accurate MTSS placement and reduces reliance on rigid cut scores.

2. Fluency and Processing Speed Receive Greater Emphasis

Many students decode accurately but read slowly or with great effort. The updated dyslexia definition elevates fluency, automaticity, and processing speed as essential components of both screening and instruction.

3. Dyslexia Persists Despite Effective Instruction

The updated definition clarifies that dyslexia is not caused by weak teaching or lack of effort. When students continue to struggle even after receiving strong, research-aligned instruction, the persistence of difficulty becomes a meaningful indicator of dyslexia.

4. The Causes of Dyslexia Are Complex and Interacting

Genetic, neurobiological, environmental, and developmental factors contribute to dyslexia. This reinforces the need for comprehensive evaluations, not checklist-based identification.

5. Morphological Processing Plays a Larger Role

For the first time, the updated dyslexia definition identifies morphology as an area of potential difficulty. Districts should ensure instruction in:

• Prefixes and suffixes

• Roots

• Word structure

• Morphological vocabulary

This shift may require curriculum updates, especially in grades three through twelve.

6. Early Oral Language Weaknesses Are Predictive

Early language skills strongly predict later reading outcomes. Districts benefit from implementing early language screening and vocabulary-rich instruction beginning in preschool and kindergarten.

7. Emotional and Long-Term Impacts Are Recognized

The updated dyslexia definition acknowledges that dyslexia affects confidence, motivation, and engagement. This encourages stronger collaboration between academic teams, SEL specialists, and mental health staff.

8. Reading and Writing Experience Matters

Students with dyslexia often struggle with written expression, comprehension, vocabulary, and background knowledge. District leaders may need to review curriculum materials and instructional approaches to ensure they support these broader literacy components.

Key Changes in the Updated Dyslexia Definition: Bringing it All Together

The infographic below graphically represents an overview of the key updates to the definition of dyslexia. It is provided as an overview and can be used by district leaders to support communication with instructional teams, other district leaders, and families. It serves as a helpful reference as districts consider where alignment is strong and where additional updates may be needed.

This graphic illustrates the key shifts in the updated 2025 IDA dyslexia definition, highlighting the move from a narrow, phonics-only view to a broader, whole-child and spectrum-based understanding.

Why the Updated Dyslexia Definition Matters

for District Leaders

The updated dyslexia definition provides a clearer and more comprehensive understanding of dyslexia that reflects research and classroom realities. This foundation supports district leaders as they strengthen literacy systems and ensure equitable access to early identification and intervention.

For district leaders, the updated dyslexia definition affects:

• Universal screening and identification

• Eligibility documentation for IEPs and 504 plans

• Structured literacy implementation

• Professional learning and coaching

• Early childhood language initiatives

• Alignment with state dyslexia laws

• Consistent communication with families

It also highlights the need for robust district data systems that capture fluency, morphology, oral language, and processing efficiency. These indicators should be reflected in progress monitoring and instructional decision-making.

Districtwide alignment is essential. The updated dyslexia definition reinforces the need for consistent expectations and systems across all schools.

District teams that understand the updated dyslexia definition are better prepared to align MTSS, screening, instruction, and communication across all schools.

What the Updated Dyslexia Definition Means for District Leaders

Earlier and More Accurate Identification Under the Updated Dyslexia Definition

The expanded indicators in the updated dyslexia definition allow districts to identify students earlier and more accurately. Many districts begin with screening updates and professional learning, followed by MTSS refinement and curriculum review.

Expanded Instructional Priorities Aligned With the Updated Dyslexia Definition

District leaders should ensure core instruction includes morphology, oral language, vocabulary, and fluency. Expanding Tier 1 expectations reduces pressure on intervention and promotes equitable literacy outcomes.

Updated Screening Approaches Reflect the Updated Dyslexia Definition

Districts may need screening tools that measure:

• Oral language

• Vocabulary

• Morphological awareness

• Processing efficiency

• Rapid word retrieval

• Fluency

These indicators help identify students who might otherwise be missed.

Stronger MTSS Systems to Support the Updated Dyslexia Definition

District MTSS structures should include:

• Fidelity checks

• Clear decision-making protocols

• Regular progress monitoring

• Tiered supports aligned to student needs

Consistency across schools ensures equitable processes and outcomes.

Professional Learning Needs Expand With the Updated Dyslexia Definition

Teachers, specialists, and leaders require deeper knowledge in:

• Morphology

• Fluency development

• Language instruction

• Orthographic mapping

This strengthens instructional consistency across classrooms and buildings.

Emotional Well-Being Takes on Greater Importance in the Updated Dyslexia Definition

Students with dyslexia may experience frustration, avoidance, or reduced confidence. Districts should incorporate SEL supports into literacy planning to promote engagement and resilience.

How Level the Learning Field Helps Districts

Align With the Updated Dyslexia Definition

District alignment requires shared understanding, structured implementation, and sustained support. Level the Learning Field (LLF) provides tools that help districts turn research into practice.

Dyslexia Simulations

Interactive simulations that deepen understanding of the learner experience and strengthen instructional decision-making.

Teacher Self Assessment: Teaching With Dyslexia in Mind

Supports teachers in identifying strengths and growth areas related to dyslexia aligned instruction.

Administrator Self Audit

Helps leaders evaluate system readiness, identify gaps, and prioritize improvements to MTSS, screening, and instruction.

Implementation Toolkit

Provides practical tools that help districts achieve consistent, high-quality literacy practices across classrooms.

Final Thoughts

The updated dyslexia definition offers the clearest scientific understanding of dyslexia to date. For district leaders, this update is an opportunity to strengthen literacy systems, improve identification accuracy, increase instructional capacity, and support students academically and emotionally.

Stronger definitions lead to stronger systems. Stronger systems lead to stronger student outcomes.

Frequently Asked Questions for District Leaders

1. How should our district begin aligning to the updated dyslexia definition?

Start with a review of screening tools, MTSS structures, curriculum materials, and professional learning. Identify gaps between current practice and the updated definition. Many districts begin with training and screening updates before adjusting MTSS and curriculum.

2. Do we need new screeners to meet the updated dyslexia definition?

Not always, but many districts will. Tools should measure fluency, morphology, oral language, vocabulary, and processing efficiency. A broader screener reduces false negatives and improves identification accuracy.

3. How does the updated dyslexia definition affect eligibility for IEPs and 504 plans?

The definition supports more thorough documentation of student needs. Teams should evaluate fluency, morphology, oral language, and persistence despite instruction. Strong data improves decision-making and services.

4. How will Tier 1 instruction need to change?

Core instruction should include morphology, fluency, oral language, and vocabulary, not only phonics. District leaders may need to review curricula or provide supplemental materials to ensure these areas are embedded.

5. What kind of professional development is most important now?

Training should focus on morphology, fluency instruction, orthographic mapping, and language development.

6. What role does SEL play in supporting students with dyslexia?

Students with dyslexia often experience anxiety, frustration, or reduced confidence. Integrating SEL supports into literacy systems helps promote engagement and resilience.

7. How can Level the Learning Field support our district in making these changes?

LLF offers dyslexia simulations, administrator audits, teacher self-assessments, and implementation tools that help districts align systems to the updated dyslexia definition and sustain improvements over time.

If your district is preparing to align screening, instruction, MTSS, and professional learning with the updated dyslexia definition, Level the Learning Field can help.

Contact our team at support@levelthelearningfield.com or by phone at 774-0234-6074 to explore simulations, audits, and tools that promote consistent, research-aligned practice.