MTSS vs. RTI: How RTI Works Inside MTSS, and Why the Academic Tier Still Decides Results

Although MTSS and RTI are both approaches to intervention, they differ in what they are trying to achieve. MTSS (Multi-Tiered System of Supports) is a broader framework that supports all aspects of a student’s growth, including behavior, academics, attendance, and more.

RTI (Response to Intervention) has a narrower purpose: academic intervention. Its goal is to identify a student’s level of understanding and help them master grade-level material.

The question isn’t whether to choose between MTSS and RTI. It’s whether the academic tier inside your MTSS is doing what it’s meant to do and helping students make progress.

What Are the Specific Differences Between MTSS and RTI?

RTI is a tiered framework for academic support, primarily in reading and math. MTSS wraps academics together with behavior, social-emotional, and attendance supports. It also looks at how schools or districts can improve the systems they use to support students.

One federal rule applies to both: neither RTI nor MTSS can be used to delay or deny a special education evaluation. OSEP Memo 11-07 addresses this requirement in the context of RTI and applies the same principle to MTSS.

How Effective Is RTI?

RTI is one of the stronger practices in education research. In the current version of John Hattie’s Visible Learning MetaX database (v1.4, February 2026), RTI has an effect size of 0.73, drawn from eight meta-analyses covering 180 studies and more than 11,000 students. That’s nearly double Hattie’s 0.40 hinge point, the average effect across the influences he tracks. MetaX rates RTI as having the potential to considerably accelerate learning.

Earlier editions reported RTI effect sizes of 1.07 or 1.29. The current MetaX figure is 0.73, which is still well above average. Because MetaX doesn’t report a separate effect size for MTSS, these findings speak to RTI rather than the broader MTSS framework.

Why RTI Works

RTI isn’t a single program. It’s a way of organizing several practices that each have strong evidence behind them.

• Catching struggles early. Universal screening finds students who are struggling while their gaps are still small and easier to close.
• Targeted, small-group instruction. The What Works Clearinghouse’s RTI practice guide for reading gives a strong evidence rating to Tier 2 instruction: intensive, systematic teaching on up to three foundational reading skills in small groups for students who score below the screening benchmark. The companion guide for elementary math recommends systematic instruction during intervention.
• Data that changes instruction. Progress monitoring tells teachers whether an intervention is working while there’s still time to adjust. The reading guide rates regular progress monitoring of at-risk students as moderate evidence and recommends checking Tier 2 students at least monthly.

What Makes It Work

Outcomes depend in part on how intervention is implemented. RTI delivers most when three things hold:

• Intervention adds time instead of replacing core instruction.
• Students are placed according to their specific skill gaps.
• Progress is checked often enough to change course.

A federal evaluation of RTI practices in elementary reading illustrates why these decisions matter. The Institute of Education Sciences examined RTI practices in 146 elementary schools across 13 states. For grade 1 students who scored just below their schools’ reading intervention eligibility cutoffs, assignment to intervention did not improve reading outcomes. The study found negative effects on spring reading scores. The researchers suggested that inaccurate placement or a mismatch between students’ needs and the interventions they received might help explain the findings. 

The evaluation highlights an important point: identifying students for intervention isn’t enough. Placement, instructional fit, and scheduling all matter. These are district-level decisions, and we’ll get to them after looking at what the rest of MTSS adds.

Does Improving Behavior Raise Achievement?

Not on its own, but it makes academic growth a lot easier. That’s the real reason RTI belongs inside MTSS. Behavior, social-emotional, and attendance supports can help create conditions where academic intervention can actually land.

• Students can’t learn from instruction they’re not in. Every office referral and suspension pulls a student out of class. In a five-year randomized trial in 37 Maryland elementary schools, schools trained in schoolwide positive behavioral interventions and supports (PBIS) saw significant drops in suspensions and office referrals. A related analysis in Pediatrics found that students in those schools were 33% less likely to be sent to the office. A Maryland statewide analysis also found that PBIS-trained schools improved reading and math proficiency.
• Social-emotional skills support achievement. A meta-analysis of 213 school-based SEL programs covering more than 270,000 K-12 students found that, in the studies that measured academics, participants scored the equivalent of 11 percentile points higher on achievement tests than students in comparison groups.
• The link runs both ways. In a study that followed students from kindergarten through grade 5, kindergarten reading skills and early behavior predicted how many discipline referrals students received in fifth grade. Problem behavior can sometimes be a way to escape work that’s too hard. In one small study, matching reading instruction to students’ actual level reduced problem behavior for three of the four students.

None of this replaces academic intervention. A five-year study of 350 students in seven at-risk schools found that behavior and achievement are related, but teaching one doesn’t automatically improve the other. Behavior and SEL supports help create the learning environment; the academic tier does the teaching. That’s why the two belong in the same system, and why the academic tier still needs its own focus.

Why Does the Academic Tier Need Its Own Focus?

The academic tier has the most direct evidence on achievement. MTSS is still the right container and provides a broader framework, but the academic aspect of intervention is still essential.

1. It’s what accountability measures. State tests, growth measures, and subgroup targets are academic, and those are the results a chief academic officer brings to the board.
2. It carries legal weight. State criteria for identifying specific learning disabilities must permit a process based on a student’s response to intervention. As a result, the quality of intervention and progress data matters when an eligibility team relies on that information. 
3. It lightens the behavior load. Since early academic struggle can predict later referrals, strong academic intervention can double as behavior prevention.

So, what separates effective academic intervention from less effective implementation? Often, it comes down to decisions made at the district level, and that’s where an MTSS investment can pay off.

Five District Decisions That Can Decide Whether Your RTI Works Inside MTSS

The right approach depends on how districts schedule intervention, place students, and use progress data. The following five decisions can help districts strengthen academic intervention within their MTSS framework.

1. Protect intervention time outside the core block

The IES evaluation described above found that about two-thirds of the schools delivered some grade 1 intervention during the core reading block. As a result, students received intervention in place of core reading instruction rather than getting more of both. 

Build a dedicated intervention block into the master schedule so Tier 2 and Tier 3 support adds instructional time rather than replacing it. Kentucky’s MTSS regulation takes a similar approach, defining Tier 2 as supplemental to Tier 1, not a replacement.

If that block needs staffing or a new tool, see our guide to making the case for intervention funding.

2. Give students near the cut score a second look

The IES study’s authors flagged imprecise placement near the cut score as a likely reason those grade 1 students didn’t benefit. Treat your screener as the first gate, and confirm placement with a diagnostic for students who land near the cut. 

3. Match the intervention to the skill gap

The researchers also suggested that a mismatch between the intervention and students’ needs could help explain the results. Reteaching grade-level content rarely closes a gap that opened two grades earlier. Find where the skill actually breaks down by working backward through prior-grade standards, and start intervention there. 

4. Monitor progress on a fixed cadence, with clear exit and intensify rules

The Center on MTSS offers examples like biweekly monitoring at Tier 2 and weekly monitoring at Tier 3. Write exit and intensify rules down before the first data review, not during it. And watch fidelity of usage: students need to use the intervention consistently enough to produce data you can act on.

5. Review academic and behavior data at the same table

Because early academic struggle predicts later discipline referrals, academic and behavior data tell you more together than apart. Align your academic and behavior screening calendars, and add this question to your team protocol: when a referral pattern shows up, have we checked the student’s academic skill level before choosing a behavior intervention?

Where to start depends on how your district is set up. If one person or a small team owns MTSS, RTI, and testing, decisions 1 through 3 are usually the most manageable place to begin. If academic and behavior supports sit with different teams or departments, decision 5 will likely take the most work, so it’s worth starting those conversations early. 

What an Effective Academic Tier Looks Like: Liftoff in Practice

When districts make these decisions well, they create better conditions for effective academic intervention. Here’s how that plays out in districts using Liftoff, our adaptive intervention program for grades 2 to 8. These are classroom and district accounts, not controlled studies.

Protected time. One district gives students working below grade level a daily morning block in Liftoff, split between math and ELA. Because Liftoff looks nearly identical to the grade-level platform, no one is singled out. A student on grade-level work and a student in intervention can sit side by side doing what looks like the same thing. 

Grade-level teaching alongside matched intervention. In Clarendon County School District, a rural Title I district in South Carolina, NWEA MAP scores feed Liftoff learning paths while teachers keep class time on grade-level content. Instructional technology coach Jill Owens says those paths push students “from where they are to where they need to be.”

Consistent use. Sophia Brown, M.Ed., ran Liftoff twice a day as a Dallas ISD teacher and estimated that at least 70% to 75% of her students showed growth, including students in special education. Her advice: “You can’t just log in once or twice a week.”

Tools alone don’t guarantee effective intervention. Students need dedicated time beyond core instruction, interventions matched to their specific skill gaps, and consistent use that produces data educators can act on. These are the elements that make academic intervention effective within MTSS.

If you’re ready to see how Liftoff can support the Tier 2 and Tier 3 academic intervention inside your district’s MTSS, schedule a demo below.