Education Cost Sharing (ECS) Formula
The Education Cost Sharing (ECS) formula is the method the State of Connecticut has established to distribute approximately $2.46 billion annually in state education funding to local and regional public school districts.
The ECS formula is made up of several different components: the foundation, student need-based weights, the Base Aid Ratio, and the phase-in schedule.
Several components of the ECS formula (the foundation and weights) are also partially used to provide funds to public schools of choice, such as magnet schools, AgriScience programs, and state charter schools.
This page provides an overview of each of the ECS formula's components and how they impact students, schools, and communities.
Foundation
In an education funding formula, the foundation amount is intended to represent the estimated cost of educating a general education student who does not have any additional learning needs.
The foundation in the ECS formula is $11,525 per student. However, this foundation amount is not based on any data or analysis of the actual costs associated with educating a general education student in Connecticut.
Additionally, the foundation amount is not adjusted to reflect the annual increase in expenses such as the rising costs of personnel pursuant to collective bargaining contracts, energy costs, or inflation. As a result, the current foundation amount has been in place, without adjustments, since 2013.
Weights
Students with certain learning needs are more likely to need additional resources in order to have equal access to educational opportunities. In order to assist districts and schools serving students with higher learning needs, school funding formulas often include weights for specific student needs.
Weights are used in school funding formulas to drive greater funds to students (ex. low-income students, multilingual learners, students with disabilities) who have been found to require additional resources and educational supports to achieve at the same levels as their non-need peers.
The ECS formula contains three “need-student” weights, which increase per-student state education aid for students with additional learning needs. Below is a description of each of the weights in the ECS formula.
Low-Income Student Weight
- Increases foundation amount by 30 percent for students who live in economically disadvantaged households as measured by eligibility for free or reduced-price lunch (FRPL)
Concentrated Poverty Weight
- Increases foundation amount an additional 15 percent (for a total of 45 percent) for economically disadvantaged students residing in districts where 60 percent or more of the enrollment is considered economically disadvantaged
- Weight applies only to a district’s low-income students above the 60-percent level
Multilingual Learner Weight
- Increases foundation amount by 25 percent for students who are identified as needing additional English-language skills
Base Aid Ratio
The Base Aid Ratio is the variable in the ECS formula that determines each community’s ability to financially support its public schools. The Base Aid Ratio acts as an equity metric to distribute state education funding through the ECS formula, with the towns with the least ability to fund their public schools receiving the most state aid.
The Base Aid Ratio uses two elements to calculate a town’s ability to fund its public schools: a property wealth factor and an income wealth factor. The property wealth factor counts for 70% in determining a town’s Base Aid Ratio, while the income wealth factor counts for 30%. Below is a description of both factors.
Property Wealth Factor
- Counts for 70% of a town’s Base Aid Ratio
- Determined using a town’s Equalized Net Grand List per Capita (ENGLPC), compared to the state median town ENGLPC
- ENGLPC is the amount of taxable property (at 100% of fair market value) per person in a city or town
Income Wealth Factor
- Counts for 30% of a town’s Base Aid Ratio
- Determined using a town’s Median Household Income (MHI), compared to the state median MHI
- MHI refers to the income level earned by a given household where half of the homes in the area earn more and half earn less
PIC Index Bonus
The ECS formula also adds additional funding for communities that have one of the highest Public Investment Communities (PIC) index scores. Under the formula, if a town has one of the 19 highest PIC index scores, the town receives a bonus of three to six percentage points to its Base Aid Ratio — resulting in increased state education aid to the town. The chart below outlines the additional percentage point bonus towns with one of the 19 highest PIC index scores will see added to their Base Aid Ratio.
Phase-in Schedule & Hold-Harmless Provisions
Fiscal year 2026 (the 2025-26 school year) marks the completion of the ECS formula's 8-year phase-in schedule and the first time in state history that the formula will be fully funded.
From FY 2019 to FY 2025, towns considered "underfunded" according to the ECS formula received gradual increases to their ECS grants. For FY 2026, "underfunded" towns will receive their fully funded grant amount for the first time, and will continue to receive their full calculated ECS grant amount each fiscal year going forward.
In addition to the gradual increasing of ECS grants for "underfunded" towns, the ECS formula also contains a schedule for gradual reductions in ECS funding for towns considered "overfunded" according to the formula. These gradual decreases began in FY 2019 and were originally scheduled to continue through FY 2028. However, the Connecticut General Assembly has routinely delayed these scheduled reductions — opting instead to fund "overfunded" towns at their ECS grant amounts for the prior year and extend the timeline for when grant reductions are to occur.
Hold Harmless for "Overfunded" Towns
As part of the current state budget, towns that are "overfunded" are “held harmless" for the next two fiscal years (FYs 2026 and 2027) and will not experience decreases in their ECS funding as previously planned. Instead, these towns will receive the same grant amount they received for the previous year.
This marks the third straight state budget cycle the legislature has instituted a hold-harmless provision for towns considered "overfunded." As a result, the ECS formula’s phase-out schedule is now set resume in FY 2028 and proceed with gradual reductions until FY 2034. Click here for a table detailing the schedule for these gradual reductions in the future.
Hold Harmless for Alliance Districts
There is also a hold-harmless provision for Alliance Districts, which are identified as 36 of the lowest-performing school districts in the state. Alliance Districts that would otherwise receive a decrease in ECS funding, according to the formula, are permanently held harmless to the greater of their FY 2017 ECS grant amount, prior year ECS grant, or current year ECS grant.
It is important to remember the ECS formula is calculated on an annual basis using updated district and town data. As a result, a town’s calculated ECS grant will change as its district and town inputs change.
Additionally, as a town’s calculated ECS grant changes, so does the difference between the town’s calculated ECS grant and its prior year ECS grant, which impacts whether a town will receive an increase in funding, be held harmless at their current grant amount, or (in the future) be potentially subject to a decrease in funding.
Other Formula Components
Regional District Bonus
The Regional District Bonus provides additional funding to towns that send students to a regional school district or one of Connecticut's three endowed academies. The Regional District Bonus is scaled based on the number of student grades educated by the regional school district or endowed academy. Towns receive $100 for each student and each grade sent to a regional school district or endowed academy.
For example, a town sending 10 students to a regional high school (four grades) would receive $100 x 10 students x 4 grades = $4,000. The Regional District Bonus is calculated prior to the ECS phase-in, which means this example town would not receive the entire $4,000 prior to the ECS grant being fully funded.
Statewide Guaranteed Wealth Level (SGWL)
Commonly referred to as the threshold factor, the SGWL determines each town’s ECS aid percentage. Each town’s ability to support its public schools (as determined by the Base Aid Ratio) is compared to the SGWL to determine what percentage of the per-student funding amount the town will receive from ECS aid and what will have to come from local tax dollars. As the SGWL is lowered, and all other formula factors remain constant, the formula distributes education aid more equitably.
Minimum Aid Ratio
Under the ECS formula, all districts are guaranteed some state education aid, even when the result of the ECS formula calculation would be that a town would not be entitled to receive ECS grant funding. This guarantee is the result of the formula’s Minimum Aid Ratio, which is 10% for Alliance Districts and Priority School Districts and 1% for all other districts.
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