ESSA Tiers of Evidence vs. Evidence for ESSA: Key Differences

District leaders are often asked to make high-stakes decisions about which programs to adopt, how to allocate resources, and whether those choices will qualify for federal funding. Yet one common challenge lies in the term ESSA evidence. Two different systems use similar language: The ESSA Tiers of Evidence, defined by federal law, and Evidence for ESSA, an independent review tool created by Johns Hopkins University. While the names sound alike, the two systems serve different purposes, and only one determines eligibility for federal funding.

Understanding this distinction matters. When administrators face competing priorities, clear insight into which programs meet federal requirements helps ensure investments support both student outcomes and compliance. For those seeking a deeper dive into how research frameworks shape educational practice, see a Full Breakdown of the Science of Reading Components.

This blog post will explain the differences between ESSA Tiers of Evidence and Evidence for ESSA, then show where Lexia’s programs fall within the ESSA framework so district leaders can make confident, well-informed decisions.

What Is ESSA?

District leaders are responsible for ensuring the programs they select not only improve student learning but also qualify for federal support. The Every Student Succeeds Act (ESSA), signed in 2015, sets the rules for how those choices are made. Unlike its predecessor, No Child Left Behind, ESSA strikes a balance between accountability and flexibility, granting state and district leaders more control while mandating evidence-based interventions.

For district leaders, this matters because federal funding is directly tied to whether chosen programs meet ESSA’s evidence requirements. When weighing different options, leaders need to know which solutions meet ESSA evidence requirements so they can invest with confidence and stay compliant.

Key provisions of ESSA include:

• Upholding equity by protecting high-need and historically underserved students.

• Requiring all students learn at challenging academic levels that get them ready for college and career success.

• Mandating annual statewide assessments to monitor progress.

• Encouraging educators to create innovative solutions that are tailored to the unique needs of their local communities.

• Holding district leaders accountable for improving outcomes in the lowest-performing schools.

What Are ESSA Tiers of Evidence?

When deciding which programs to adopt, administrators need a clear, federally recognized framework for assessing research quality. That’s what the ESSA Tiers of Evidence provide. These categories help district leaders determine which programs qualify for federal funding and which are still considered too early in development. By relying on this framework, leaders can make decisions rooted in research.

The 4 tiers of ESSA evidence are:

1. Tier 1: Strong Evidence

   • Backed by at least one well-designed and well-implemented randomized controlled trial.

   • Considered the gold standard because results show clear cause-and-effect relationship between a program and student outcomes.
     
     

2. Tier 2: Moderate Evidence

   • Supported by well-designed quasi-experimental studies.

   • These studies compare groups but may not use random assignment, offering reliable but somewhat less rigorous findings.
     
     

3. Tier 3: Promising Evidence

   • Based on correlational studies with statistical controls for selection bias.

   • Shows meaningful links between program use and improved student performance, but without experimental design.
     
     

4. Tier 4: Demonstrates Rationale

   • Requires a logic model grounded in research, plus a commitment to ongoing study.

   • Encourages innovation by supporting programs still building their evidence base.

For district administrators, the takeaway is straightforward: Programs in Tiers 1–3 qualify as evidence-based under ESSA and are eligible for federal funding. Tier 4 programs may be used strategically if paired with a plan to strengthen the evidence throughout time.

What Is Evidence for ESSA?

While ESSA itself sets the federal standard for evidence, administrators often turn to third-party reviews when comparing options, and Evidence for ESSA was designed for that purpose. It provides accessible program ratings that can help district leaders evaluate choices. Its purpose is to help educators and administrators compare programs by providing clear, accessible summaries of research.

How Evidence for ESSA works:

• Reviews programs against criteria aligned to ESSA, but applies its own methodology.

• Rates interventions using three categories:

  • Strong

  • Moderate

  • Promising

• Provides an external, third-party perspective that some district leaders use when evaluating program options.

For leaders, the key distinction is that ESSA Tiers of Evidence are the criteria that determine federal funding eligibility. Evidence for ESSA can be a helpful comparison tool, but it does not replace the requirements set by law.

Lexia’s Tiers

District leaders face constant pressure to ensure every program they adopt is both fundable under ESSA and proven to deliver results. With budgets tied to compliance, the stakes are high: Choosing a program that doesn’t meet ESSA standards can mean lost funding, wasted resources, and stalled progress on student outcomes.

To support confident decision-making, Lexia’s portfolio has been rigorously evaluated against the ESSA Tiers of Evidence framework. Each program meets the federal definition of “evidence-based,” ensuring administrators can move forward knowing their investments are not only effective but also fully fundable.

Lexia® Core5® Reading—Tier 1: Strong Evidence

Core5 is supported by more than seven high-quality studies that meet ESSA’s Strong Evidence criteria. These randomized controlled trials demonstrate clear, positive impacts on foundational literacy outcomes, giving district leaders confidence Core5 qualifies for federal funding.

Lexia® PowerUp Literacy®—Tier 1: Strong Evidence

Like Core5, PowerUp has ESSA strong studies, four showing that students using PowerUp make significant gains, placing it firmly in the Tier 1 category under ESSA.

Lexia English Language Development™—Tier 2: Moderate Evidence

Lexia English has been evaluated through well-designed quasi-experimental studies. These findings meet ESSA’s Moderate Evidence criteria, confirming the program is eligible for federal funding while continuing to build toward a Tier 1 evidence base.

Lexia® LETRS® Professional Learning—Tier 2: Moderate Evidence

LETRS, including Lexia® LETRS® for Early Childhood Educators, is backed by experimental and quasi-experimental studies that demonstrate strong impacts on teacher knowledge and classroom practice. This places LETRS at Tier 2, underscoring its alignment with ESSA’s most rigorous standard.

Lexia Aspire® Professional Learning—Tier 4: Demonstrates a Rationale

As a newer offering, Aspire currently falls into the Demonstrates a Rationale category. Correlational studies show meaningful connections between Aspire participation and improved educator practice, while additional research is underway to expand its evidence base.

Bottom line for administrators: Whether your priority is early literacy, secondary reading support, English language development, or professional learning, Lexia® solutions align with ESSA’s evidence standards—removing uncertainty about funding eligibility.

What Should District Leaders Use?

When making investment decisions, administrators should anchor their choices to ESSA’s federal tiers. These are the standards written into law, and they dictate which programs are eligible for funding. These tiers determine whether programs qualify for federal funding and provide a consistent, government-backed framework for evaluating educational interventions.

While Evidence for ESSA can be a useful resource for comparing products, it is not the system that drives funding decisions. Administrators making investment choices should prioritize programs that meet the federal ESSA tiers, particularly those in Tiers 1–3, which qualify as evidence-based under the law.

For district leaders, this means:

• Focus on ESSA Tiers of Evidence when determining program eligibility for funding.

• Recognize Lexia programs meet these standards, Core5 and PowerUp at ESSA Strong, LETRS and Lexia English at ESSA Moderate, and Aspire at ESSA Demonstrates a Rationale.

• Use third-party reviews like Evidence for ESSA for added perspective, but always anchor decisions to the federal criteria.

By aligning program selection with the official ESSA tiers, administrators can ensure investments are not only research-driven but also fundable under federal guidelines.

For administrators navigating competing priorities and limited budgets, clarity about evidence frameworks is essential. The good news is the path forward is clear: ESSA Tiers of Evidence provide a reliable framework for identifying which programs qualify for federal funding, and Lexia’s portfolio is strongly aligned with these standards.

• Core5—ESSA Strong Evidence (highest standard under the law)

• PowerUp—ESSA Strong Evidence (highest standard under the law)

• Lexia English—ESSA Moderate Evidence

• LETRS—ESSA Moderate Evidence

• Aspire—ESSA Demonstrates a Rationale (logic model with ongoing research)

By choosing programs that meet ESSA requirements, district leaders can feel confident their investments are both fundable and effective in improving student outcomes.

See the full evidence base for Lexia solutions and explore detailed findings you can share with your team at Product Efficacy and ESSA Evidence.