Expanding publicly funded pre-K: How to do it and do it well

Preschool enrollment fell across the United States during the COVID-19 pandemic, with the nation’s lowest-income families experiencing the most precipitous drop.1 And among school-age children, historically disadvantaged students saw achievement gaps widen even further.2COVID-19 and education: The lingering effects of unfinished learning,” McKinsey, July 27, 2021.

This disruption to children’s schooling, including prekindergarten (pre-K) for children ages three through five, was a major contributor to the pandemic’s disproportionate impact on women, children, and low-income households.3 While the return to the classroom marked a return to stability for many families, the economic, health, and social challenges that disproportionately affected low-income households, women, and historically marginalized communities still exist.4 States now have an opportunity to strengthen the foundation that supports families, particularly those in poverty, by implementing best-in-class pre-K educational programs.

The benefits of a high-quality early childhood education are supported by rigorous research and can touch many corners of society. Quality pre-K education programs help children from all backgrounds, with proven long-term benefits in academic, mental-health, and social outcomes. For children from historically disadvantaged communities, pre-K can help break the cycle of poverty (see sidebar “The potential benefits of public pre-K”).5 But how state and local governments invest in pre-K education matters tremendously. Recent studies have found that investments that fail to focus on program quality can backfire and negatively affect students’ long-term achievement.6 High-quality programs, by contrast, can produce pre-K graduates who have stronger educational outcomes through high school and into adulthood.7

To ensure best-in-class, cost-effective pre-K programs, state and local leaders can assess the needs of their population and their available budget and then take lessons from districts that have implemented these programs successfully. To help with those efforts, we have identified eight elements that have yielded pre-K programs that have delivered positive impacts for students and taxpayers. Drawn from research and the experiences of dozens of jurisdictions, these elements prioritize lessons from states and municipalities with programs that have resulted in positive outcomes for children from kindergarten to 12th grade. We also explore six major decisions that states typically make regarding program design, the trade-offs those decisions could entail,8 and the cost considerations for standing up a high-quality program. For states that decide to invest in pre-K, this could provide a road map for how to design a program that will be both high quality and cost-effective.

Research-backed, parent-approved: The elements of a high-quality pre-K program

Large-scale, publicly funded pre-K programs exist in many states and large cities across the country, and many have been rigorously studied. Across the research, the evidence is clear: one of the single greatest drivers of child outcomes, both academically and behaviorally, is high-quality interactions between teachers and students.9

States can make intentional design choices that could enable the kinds of high-quality teacher–student interactions that lead to positive outcomes. This often requires clear decisions and investment up front and sustained attention from stakeholders all along the delivery chain. Across successful programs, we’ve identified eight specific variables that support high-quality instruction and interactions in early childhood education. Each of the eight variables involve providing the necessary time, space, and support for teachers and students to learn and develop meaningful connections.10

Sufficient time in the classroom

Studies show that full-day pre-K programs lead to better student outcomes than half-day programs.11 And parents report higher satisfaction with full-day programs because they make it easier to accommodate work and other responsibilities.12

Opinions vary over whether “full day” pre-K—typically about six hours—is sufficient for a full-time working parent; some systems supplement with paid aftercare or other options for working families to extend the day.13

Low teacher-to-child ratio

Small class sizes are easier to manage, allowing for more individualized instruction and improved safety and supervision. For this reason, high-quality programs typically limit their teacher-to-child ratio to 1:10, with a maximum of 20 children in a classroom with two adults, typically including a lead teacher and an assistant teacher.14

Developmentally appropriate learning standards

Just as in K–12 education, standards that determine what children should learn in pre-K can drive classroom practice and accountability. Most states have a set of standards in place, but these standards vary.15 High-quality pre-K standards in general strive to address the specific academic and social needs of four-year-olds16 and directly shape curricular choices and professional development for teachers. Nationally standardized expectations, such as the Head Start Early Learning Outcomes Framework, could provide a road map for determining learning standards in line with state and local expectations of children in grades K–3. A lack of alignment risks compromising students’ learning and could require kindergarten teachers to undergo redundant instruction.17

Just as in K–12 education, standards that determine what children should learn in pre-K can drive classroom practice and accountability.

Effective curriculums

Multiple research studies have demonstrated that young children learn social and academic skills best and most easily through play.18 Historically, more affluent families have gravitated most toward play-based early-learning models, but all children, including those from low-income households, could benefit from this approach.19 Similar to learning standards, linking pre-K and K–3 curriculums could ensure smooth learning transitions and logical content progressions for children.

Specialized teacher education

Strong pre-K programs tend to have lead teachers with specialized training in early childhood instruction and child development.20 At present, nearly all successful programs require a minimum of a bachelor’s degree for lead teachers. However, given the current labor shortage in early childhood education, states may want to consider a skills-based approach to identify those who have the skills to be successful but who have not yet obtained the credentials (that is, creating an on-ramp for currently uncertified early childhood teachers).21

Ongoing professional development

Successful programs offer teachers ongoing professional development that is aligned to the curriculum, incorporate on-the-job coaching, and include practical activities such as role-playing and demonstrations. This training is most effective when teachers have time to practice their new skills, are supported in reflecting on their practice, and have the time and space to set goals.22 Coaching that specifically targets teacher–student interactions could improve student learning.23

Regular assessment of child progress

Individual child assessments offer visibility into a child’s progress and readiness for kindergarten. Research-backed tools such as Head Toes Knees Shoulders, the Peabody Picture Vocabulary Test, Teaching Strategies GOLD, and Woodcock–Johnson (WJ) tests measure student skills during everyday classroom activities and provide rich data for teachers to adjust their instructional practices during the year.24 Classroom-level assessments can provide data to families to inform program choice, to system administrators to maintain program accountability, and to leaders and coaches to tailor support to teachers. One of the most widely deployed assessments is the Classroom Assessment Scoring System (CLASS), which has demonstrated reliability, validity, and an ability to predict student outcomes.25

Robust data systems

Ideally, pre-K program data systems are linked to the state’s overarching K–12 data systems to track alignment and impact over time. Many states are struggling to get truly integrated systems off the ground due to a set of common barriers—fragmentation in the early childhood system, inconsistent data use and collection, and confidentiality concerns.26 Most states have adopted Quality rating and improvement systems (QRIS) as a tool to standardize and communicate publicly about early childhood program quality. Evidence from successful state programs demonstrates that pairing QRIS with other proven strategies to boost pre-K quality can be very effective.27 This has not been the case in all states, though: for QRIS to improve quality, states should consider investing in complementary program supports.

A, B, or C: Crucial pre-K program decisions

States will weigh the trade-offs of numerous decisions. Six are particularly pressing.

Define the scope: Universal versus targeted

Universal programs are open to all children, whereas targeted programs have eligibility criteria. Views differ—sometimes widely—on different program types. Ultimately, states could consider how much they could spend on pre-K and how best to meet the needs of children who stand to gain the most from a high-quality pre-K experience (see sidebar “Considering universal versus targeted pre-K”).

Locate the funding

To build a successful pre-K program, states will need a sustainable funding source, and most provide funding over and above the limited federal resources available. A few states allocate pre-K funding as part of their K–12 funding formula.28 Some states (and localities) have funded pre-K out of their general budget. Others have identified new revenue sources. Still others have used public–private partnerships for specific program components, such as new program pilots, assessment rollouts, or data system expansions. However, private funding to date has not been extensive enough to support annual operating costs for large-scale pre-K programs.

Establish clear governance

In most states, the department of education has principal oversight over the statewide pre-K program. Some states have created an agency focused on early childhood education; others split responsibilities across multiple agencies; and a few have delegated such programs to health and human services departments. Regardless of who is in charge, the decisions made at the state level have implications at the local level. Some states require funding and management to flow through local education agencies (LEAs) or similar entities, which may oversee key decisions such as determining the district’s minimum hours of pre-K operation, outlining professional-development requirements for teachers, and even establishing class size and teacher-to-student ratios.29

Determine accountability for services

States have different criteria for determining how public funds are allocated between providers. Some states mandate that funds be split between public and private providers. For example, West Virginia state law requires that 50 percent of pre-K classrooms in each county be in private settings.30 Other states leave the decision to localities. There are examples of programs with strong outcomes in a public-school-only model, such as in Boston, and of programs that allow for multiple delivery models, such as in Oklahoma.

Decide whether to serve three-year-olds

Research suggests that children benefit from a second year of high-quality preschool,31 which would translate into more children entering pre-K at age three rather than waiting until age four. Based on the research and the precedent being set by some cities, some states might consider supporting two years of preschool, which could be an immense help to low-income families.32

Given limited resources, most states and localities have focused, for now, on implementing one year of preschool. Today’s existing two-year pre-K programs—such as those in Boston, New York City, and Washington, DC—started with four-year-olds and expanded to include three-year-olds because the programs demonstrated positive outcomes and cities were able to identify additional resources to support the effort.

Offer wraparound services

Federal Head Start program standards require the provision of basic health and hygiene services, referrals for coordinated services, parent education, and a role for parents in program governance. Many Head Start and other pre-K programs include families as powerful tools for improving child outcomes by recognizing the strengths and diversity of their backgrounds and by finding ways to engage them in classroom activities. Students could benefit from additional services, but there is insufficient research to definitively conclude that this is critical to quality as states prioritize where to spend their funds—particularly given that implementation of such practices is largely determined at the classroom level or center level.33

Today’s existing two-year pre-K programs started with four-year-olds and expanded to include three-year-olds because the programs demonstrated positive outcomes.

How much will this cost?

RAND’s estimated average cost of $12,700 per child to run a high-quality, full-day pre-K program in 2019 is not far from that year’s national per-child K–12 average of $13,187.34 Actual spending on pre-K is barely half that figure: the national average in 2021 was just $6,804.35 To fund a high-quality program, states will need to narrow this gap.

Of course, there is no magic number to be spent per child to achieve high quality. However, there are prerequisites. There need to be enough teachers to maintain a reasonable classroom ratio. A full day of services for children needs to be funded, and teacher compensation needs to be sufficient to attract qualified candidates and limit turnover. The overall scale of certain administrative operations, such as assessment and coaching, varies widely from state to state and may be funded by other sources, such as local payment matching—in which case states need not bake those costs directly into their own per-child spending. And while many states have left some one-time federal stimulus funds unspent, there may be significant up-front investments they could make now to support a pre-K expansion, including spending on facilities, workforce development, and other program start-up costs.


Pre-K is an investment that delivers proven, widespread benefits, and research suggests an increasingly clear sense of how states can design programs to unlock them. There are certainly risks, particularly if the amount spent per child is insufficient for operating a quality program. But there are steps states could take to design programs that fit local circumstances, resources, and goals. The research suggests that investing in the next generation of students, particularly as we continue to recover from the economic and educational impacts of COVID-19, is likely to prove well worth the cost.

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