CAST UDL Guidelines: The 3 Principles And How To Use Them

Every student learns differently, that’s not news to any teacher. But having a framework that actually helps you design lessons for all learners? That’s where the CAST UDL Guidelines come in. Developed by the nonprofit organization CAST (Center for Applied Special Technology), these guidelines give educators a research-backed structure for creating flexible, inclusive learning experiences.

The Universal Design for Learning framework is built on three core principles: Engagement, Representation, and Action & Expression. Together, they address the "why," "what," and "how" of learning. Understanding these principles isn’t just academic, it’s practical. When applied thoughtfully, UDL can transform how you reach struggling students, challenge advanced learners, and reduce the need for constant modifications down the road.

At The Cautiously Optimistic Teacher, we’ve built resources like our UDL Lesson Plan Template because we know how powerful this framework can be when teachers actually use it. This article breaks down the three UDL principles, explains what the latest guidelines (version 3.0) include, and shows you concrete ways to apply them in your classroom. Whether you’re new to UDL or looking to deepen your practice, you’ll walk away with a clear understanding of how to make it work for you and your students.

Why CAST UDL guidelines matter in real classrooms

You’ve probably been there: you plan a lesson, deliver it, and then realize three students couldn’t access the material the way you presented it. So you scramble to create modifications, adjust on the fly, or pull students aside for reteaching. This cycle eats up your time and energy, and it’s exactly what the CAST UDL guidelines help you avoid. When you design lessons with multiple pathways built in from the start, you eliminate much of that reactive work.

They reduce the need for constant retrofitting

Traditional lesson planning often follows a "one-size-fits-all" approach that you then modify for individual students. The problem? You’re always playing catch-up. UDL flips this process by having you consider learner variability during the planning stage, not after. When you anticipate different needs upfront, you build flexibility into the lesson itself rather than creating separate versions for different students.

Think about a reading assignment. Instead of assigning the same text to everyone and then creating simplified versions for struggling readers, UDL asks you to offer multiple text options from the beginning. Some students might read the full chapter, others might use an audiobook version, and still others might work with an adapted text. Everyone accesses the same core content, but through different entry points that match their current reading level.

"When you design for the margins, you create something that works better for everyone in the middle too."

They work for all learners, not just some

Here’s what surprises many teachers: UDL isn’t just for students with disabilities or those who struggle. The framework benefits your advanced learners, your English language learners, your students with ADHD, and yes, even your "typical" students. By offering varied ways to engage, learn, and demonstrate understanding, you create a classroom where more students can show what they actually know.

Consider a student who excels at content but freezes during traditional tests. With UDL, you might offer that student the option to demonstrate mastery through a video explanation instead. Another student might prefer a written essay, while a third creates an infographic. All three options assess the same learning goals, but they remove unnecessary barriers that have nothing to do with the actual content you’re teaching.

They align with what research says about how brains learn

The cast udl guidelines aren’t based on educational trends or wishful thinking. They’re grounded in neuroscience and learning sciences research about how different brains process information. CAST synthesized decades of research to create a framework that acknowledges a simple truth: learner variability is the norm, not the exception.

Your classroom includes students whose brains process visual information quickly but struggle with auditory input. Others might need movement to maintain attention, while some thrive in quiet, still environments. Research shows that these differences aren’t deficits, they’re normal variations in how humans learn. When you apply UDL principles, you’re working with these brain differences instead of against them, which leads to better outcomes for everyone.

The practical impact shows up in your daily teaching. You spend less time creating last-minute accommodations, students engage more consistently with lessons, and your classroom management improves because fewer students disengage due to inaccessible materials or rigid teaching methods. These aren’t abstract benefits. They’re the reasons teachers who implement UDL consistently report feeling more effective and less overwhelmed.

What CAST means and what the guidelines cover

CAST stands for Center for Applied Special Technology, a nonprofit education research organization founded in 1984. The organization didn’t set out to create a framework that would transform education, they started by developing accessible technology solutions for students with disabilities. Through this work, they discovered something important: when you design learning experiences that work for students with the most significant challenges, you often create something better for everyone.

The organization behind the framework

The researchers at CAST noticed a pattern. Tools and strategies designed to help students with disabilities often benefited all learners in unexpected ways. Closed captions helped not just deaf students but also English language learners and students in noisy environments. Text-to-speech supported struggling readers while also helping auditory learners process written content. This realization led them to develop Universal Design for Learning as a proactive approach to teaching rather than a reactive accommodation model.

CAST continues to update and refine the cast udl guidelines based on emerging research in neuroscience and education. The organization provides free access to the guidelines online, along with extensive resources for educators. They partner with schools, districts, and researchers worldwide to study UDL implementation and measure its impact on student outcomes.

What the guidelines actually include

The guidelines themselves provide a detailed roadmap organized around three main principles, each broken down into specific guidelines and checkpoints. You get concrete strategies for how to apply each principle in your classroom, not abstract theory that sounds good but offers little practical help. Each checkpoint includes examples and suggestions that you can adapt to your specific content and grade level.

Think of the guidelines as a planning tool rather than a checklist you must follow perfectly. They offer multiple options for addressing each principle, and you choose which strategies fit your students, content, and teaching context. Some teachers start by focusing on one principle at a time, while others integrate strategies across all three from the beginning.

"The guidelines don’t prescribe specific teaching methods. They give you a flexible framework for making instructional decisions."

The current version also includes connections to educational standards and assessment practices, showing how UDL aligns with what you’re already required to teach. This matters because UDL isn’t something extra you layer on top of your existing curriculum. It’s a way of thinking about how you design and deliver that curriculum so more students can access it successfully.

The 3 UDL principles with classroom examples

The cast udl guidelines organize their framework around three principles that correspond to three distinct brain networks involved in learning. Each principle addresses a different aspect of the learning process, and together they create a comprehensive approach to designing instruction. You don’t need to master all three at once, but understanding how they work together gives you powerful planning tools for reaching more students.

Engagement: The "why" of learning

This principle focuses on motivating students and sustaining their interest throughout a lesson. Students engage with content for different reasons, and what hooks one learner might completely miss another. Some students love competition, while others shut down when you introduce it. Your job is to offer multiple entry points that appeal to different motivational profiles.

In practice, you might teach a unit on the water cycle by giving students choice in their project format. One group creates a public service announcement about water conservation, another designs an interactive poster, and a third writes and performs a song about the water cycle stages. Each option taps into different interests while addressing the same learning objectives. You’ve built engagement options into the assignment rather than assuming all students will feel equally motivated by a single approach.

"Engagement isn’t about making learning fun. It’s about removing barriers that prevent students from connecting with content that matters."

Representation: The "what" of learning

This principle addresses how you present information to students. Some learners process visual information quickly, others need auditory input, and still others require hands-on experience to grasp concepts. When you represent content in multiple formats, you ensure that more students can access the material regardless of their processing strengths.

Consider teaching fractions. You might use physical manipulatives like fraction bars, display visual models on your board, explain concepts verbally, and have students work through written examples. Students who struggle with abstract symbols can work with the manipulatives first, while those who grasp concepts quickly through visual patterns can move ahead using the diagrams.

Action and Expression: The "how" of learning

The third principle gives students multiple ways to demonstrate what they’ve learned. Traditional assessments often measure test-taking skills as much as content mastery, which creates unnecessary barriers for students who know the material but struggle with specific output formats.

You might assess understanding of character development in a novel by offering options: a traditional essay, a character diary with multiple entries showing growth, a visual timeline with annotations, or a recorded conversation between characters. Each format allows students to show mastery without being penalized for weaknesses in areas unrelated to your actual learning goals.

What changed in the UDL Guidelines 3.0 update

CAST released version 3.0 of the cast udl guidelines in 2024, marking the first major revision since 2018. The update doesn’t overhaul the framework or change the three core principles. Instead, it refines the language, consolidates checkpoints, and incorporates new research about how students learn. If you’ve been using earlier versions, you won’t need to throw out your existing lesson plans, but you’ll want to understand what shifted and why.

Language changes that make practical difference

The most noticeable change involves how CAST describes the guidelines themselves. The organization moved away from saying teachers should "provide" specific supports and instead uses language like "foster" and "develop." This shift matters because it acknowledges that learning happens through a dynamic process rather than through static delivery of materials.

You’ll see this in how guidelines now emphasize student agency and self-regulation rather than teacher-controlled supports. For example, instead of "provide options for comprehension," the updated version focuses on "facilitate understanding" across modalities. The change pushes you to think about creating conditions where students develop their own strategies rather than relying solely on supports you provide.

Consolidated checkpoints and updated examples

Version 3.0 reduces the total number of checkpoints from 31 to 28 by combining overlapping items and eliminating redundancy. CAST didn’t remove any concepts but rather streamlined the framework to make it more accessible for teachers planning lessons. The organization also updated all examples to reflect current technology and teaching contexts, removing outdated references to tools teachers no longer use.

The guidelines now include more specific connections to social-emotional learning and culturally responsive teaching practices. You’ll find checkpoints that explicitly address belonging, identity, and community building, areas that earlier versions touched on but didn’t emphasize as strongly.

"The 3.0 update doesn’t ask you to learn something new. It clarifies what effective UDL implementation looks like based on years of classroom research."

What didn’t change (and why you should care)

The three core principles remain identical because neuroscience research continues to support them. Your brain still has separate networks for engagement, information processing, and strategic action, which means the fundamental structure of UDL stays solid. The checkpoints under each principle might use different language, but they address the same learning needs they always have. This stability means any work you’ve done implementing UDL over the past decade remains valid and doesn’t require starting over with an entirely new framework.

How to use CAST UDL guidelines in lesson planning

The cast udl guidelines work best when you integrate them into your planning process from the beginning rather than treating them as an afterthought. You don’t need to address every checkpoint in every lesson, but thinking through the three principles before you teach helps you identify potential barriers and build flexibility into your instruction. This approach saves time because you avoid creating multiple versions of the same lesson later.

Start with your learning goals, not the guidelines

Your first step involves clarifying exactly what you want students to know and do by the end of the lesson. Write down your learning objectives before you consult any UDL framework. Once you have clear goals, you can use the guidelines to identify barriers that might prevent students from reaching those objectives. This order matters because UDL should serve your content, not the other way around.

Consider a science lesson on photosynthesis. Your objective might be that students explain how plants convert sunlight into energy. Now ask yourself: what barriers might prevent students from demonstrating this understanding? Some might struggle with scientific vocabulary, others might need visual models to grasp abstract processes, and still others might show mastery better through diagrams than written explanations. Each barrier you identify suggests specific UDL strategies you can incorporate.

"Effective UDL planning means designing around barriers, not around individual students."

Build in options during the planning phase

Once you’ve identified potential barriers, you design multiple pathways into your lesson materials and activities. For presenting information (Representation), you might include a video explanation, a text reading, and a hands-on demonstration. For engagement (Engagement), you could offer choice in topics students research or how they approach a problem. For demonstrating learning (Action and Expression), you build in different assessment formats students can choose from.

Planning with options doesn’t mean creating entirely separate lessons. It means thinking about strategic variations within a single lesson structure. You might prepare three text complexity levels for a reading, create both verbal and written instructions for an activity, or design a rubric that works across multiple project formats.

Use the checkpoints as reflection prompts

After teaching a lesson, review the UDL checkpoints to identify what worked and what didn’t. Did students stay engaged throughout? Could everyone access the material in at least one format? Did your assessment options let students show what they actually learned? These questions help you refine future lessons based on evidence rather than assumptions about what students need.

You can access the full guidelines framework and checkpoints at no cost, making them practical planning tools you can reference whenever you design instruction.

What to do next

You’ve learned how the cast udl guidelines work, what the three principles cover, and how to apply them in your planning. The framework becomes more intuitive with each lesson you design using its principles. Start small by choosing one principle to focus on in your next unit, then gradually incorporate the others as you build confidence with the approach.

Download CAST’s free guidelines and keep them accessible during your planning time. Reference the specific checkpoints that address barriers your students face most often, whether that’s engagement, accessing content, or showing what they know. You don’t need to implement everything at once, just make steady progress toward more flexible instruction.

Looking for ready-to-use resources that apply UDL principles? The Cautiously Optimistic Teacher offers lesson templates, unit plans, and practical tools designed with universal design in mind. These materials save you planning time while helping you reach more students effectively. The more you practice thinking through learner variability during planning, the more natural UDL becomes in your daily teaching.