Missouri and the four-day school week
Missouri has been at the center of the four-day school week movement, with more than a third of its districts on the schedule and a 2024 law — Senate Bill 727 — reshaping how districts adopt and keep it.
District map & school list
192 Missouri public (non-charter) districts are on a four-day school week in 2026–27, up from 185 in 2025–26: eight districts joined, and one, Sunrise R-IX, was required by law to return to five days for at least a year after missing the vote deadline set by SB 727. We count a district as four-day if it is on the schedule for at least 75% of the school year; the count excludes districts that have since returned to five days. DESE’s own historical list differs from ours — a few districts on it were never actually on a four-day week — so treat any single number here as a careful estimate rather than a census.
SB 727: requirements and election results
As of July 1, 2026, any district located wholly or partially in a charter county (Jackson, Clay, St. Louis, Jefferson, and St. Charles) or in a city with 30,000 or more residents must have:
- 1,044 hours and 169 days of instruction, or
- a four-day week approved by voters with at least 142 days — a “yes” vote locks in the schedule for ten years.
A financial incentive is paid to any district offering at least 169 instructional days. Rural districts under 30,000 residents and outside charter counties can still adopt the four-day week by school-board vote.
Read the full text of SB 727 → (PDF backup)Every district that has put the four-day week to a public vote has passed it, with support ranging from about 62% to 87% — consistently higher than typical pre-adoption parent surveys. Observers credit communities having lived with the schedule before voting on it.
How each district voted
Missouri implementation research
State-level studies of the four-day week’s effects on achievement and school finance in Missouri.
What Missouri’s newest retention data show
In July 2026, DESE filled a data request from our team covering teacher retention in every Missouri district for the six school years 2019–20 through 2024–25 — the freshest statewide look yet at whether the four-day week helps districts keep their teachers. We analyzed all 513 traditional districts, excluding three whose large statewide virtual programs would distort the picture. This is our own analysis of the raw data, not yet peer-reviewed — read it with the same caution we ask of any working paper.
Districts that adopt the four-day week were already struggling to keep teachers. In the years before switching, future adopters ran about 3.3 percentage points below rural districts that remained on five days through 2025–26 in one-year retention. The twelve districts that adopted in 2025 ran 3.5 points behind that comparison group throughout their five-day years. Struggling to retain teachers is part of who chooses this schedule — so simply comparing four-day and five-day districts mostly measures who adopts, not what adoption does.
After switching, adopters roughly stopped falling further behind — through the worst teacher market in memory. From a 2019–21 baseline through 2024–25, rural districts that adopted in 2022–24 lost about two points of one-year retention while rural districts that remained on five days through 2025–26 lost about four. That relative difference is not statistically significant, and it does not appear at all in three-year retention.
And nobody caught up. Four-day districts have not closed the gap with the comparison group; they have held their relative position while the whole state’s retention fell after COVID and only partly recovered.
In our data, the four-day week is neither the retention disaster its critics describe nor the retention fix its adopters hope for. That reading agrees with the two strongest Missouri studies to date — Thompson (2025) and the CALDER working paper by Camp, Anglum, Koedel, Lee and Nguyen — both of which find no consistent retention effect. What our data add is the view through 2024–25, past both studies, and a before-and-after picture that shows the pattern was already there before districts switched.
How to read this. Each point is the median gap between adopting districts and rural districts that remained on five days through 2025–26, in the years before and after the switch. Zero means keeping pace with that comparison group. Adopters ran three to four points behind before switching and drift toward zero — parity, not advantage — in the years after.
See the chart data
| Year relative to adoption | Gap (percentage points) | Adopter-district observations |
|---|---|---|
| −4 | −4.2 | 20 |
| −3 | −3.3 | 46 |
| −2 | −3.1 | 63 |
| −1 | −3.6 | 105 |
| Switch | −3.9 | 105 |
| +1 | −2.2 | 105 |
| +2 | −4.3 | 85 |
| +3 | −1.5 | 59 |
| +4 | +0.7 | 42 |
Rural adopters from 2021 through 2024 only. Each point is the median across adopter districts of district one-year retention minus that year’s median among the 209 rural districts that remained on five days through 2025–26.
Source: DESE data request DR 6977 (received July 2026): one-year and three-year teacher retention rates, district level, school years 2019–20 through 2024–25 (DESE labels each school year by its second calendar year). We analyzed the 513 traditional districts, excluding Grandview R-II, Laquey R-V, and Sturgeon R-V, whose statewide virtual programs dominate their teacher counts. Rates are district-level, so a teacher moving between buildings counts as retained, while one moving to the district next door counts as lost. Retention is not a measure of teacher quality. This is an original Missouri State University analysis and has not been peer reviewed. The underlying district-year table is available on request.
From the Missouri State University research team
Dr. Jon Turner and colleagues have published a series of studies on the four-day school week, focusing on rural districts, teacher recruitment, and the perspectives of parents, staff, and community leaders.
Missouri teacher shortage data
Did you know? One of the main reasons schools transition to a four-day week is the teacher shortage and the difficulty of retaining teachers, especially given pay inequity from district to district. In 2024, around 9% of Missouri public school courses were taught by non-certified teachers — roughly 2,000 non-certified teachers, up from 2023.
Contact Dr. Jon Turner
Associate Professor of Educational Leadership · Missouri State University, Springfield MO