Every fall, somewhere, a classroom opens with a long-term substitute instead of a real teacher — and it’s rarely because too few people finished a teaching degree. A new national scan of every state’s staffing data shows the actual driver is something schools have been slow to fix.
The Problem Isn’t Who’s Missing From the Pipeline
If your building is covering a class with a long-term sub again this year, you already know something is off. What you might not know is how big the gap actually is, or where it’s really coming from.
About 1 in 8 U.S. teaching jobs is either sitting empty or filled by someone not fully certified for the assignment, according to the Learning Policy Institute’s July 2026 scan of state staffing data. That’s at least 425,412 positions nationwide: 387,843 filled by teachers who aren’t fully certified for what they’re teaching, plus 37,569 confirmed vacancies in the states that publish that number. LPI has now logged a third straight year of increases among states that report the data.
It’s Not About Too Few New Teachers
The instinct is to blame the pipeline — not enough people choosing teaching in the first place. That’s part of the story, but a smaller part than most people assume. Interest among college students in becoming teachers is at a 50-year low, and prep-program enrollment dropped by roughly 100,000 candidates between 2012-13 and 2014-15, then stayed roughly flat since.
But researchers Tiffany Tan, Gian Anthony Baez, and Susan Kemper Patrick, who authored LPI’s 2026 report, point to a different number: about 90% of annual new-teacher demand comes from attrition, not growth in the number of students who need teaching. Teachers are leaving. Nearly 3 in 4 of those who moved schools or left the profession entirely did it voluntarily, for reasons that had nothing to do with retirement.
Why They’re Actually Walking Away
When departing teachers are asked why, the answers cluster around the same few things: other career opportunities, higher salaries elsewhere, and plain dissatisfaction with the job itself. LPI’s own policy recommendations are blunt about it — competitive pay and better working conditions — because most vacancies exist not because no one wanted the job, but because someone already in it walked out before retirement age. Each departure costs a district somewhere between $12,000 and $25,000 to replace.
The Shortage Isn’t Evenly Spread
Some subjects and some schools have it far worse than others. Special education is the most commonly reported shortage area, cited by 45 states, followed by science (41 states) and math (40 states). The largest raw numbers of unfilled or uncertified positions sit in special education, elementary grades, language arts, and career and technical education.
Turnover runs 35% to 37% higher in schools serving the most students of color and students from low-income families than in schools serving the fewest. Rural districts get hit from both directions at once — lower pay and a longer commute from the nearest teacher-prep program.
The Loop Tennessee Educators Are Describing
A Tennessee Education Report piece from August 2026 put the dynamic in plain classroom terms: empty rooms make the remaining job harder. A harder job pushes the next person out. Recruitment gets worse because the job itself looks worse to anyone considering it — a self-reinforcing loop that no hiring campaign can out-recruit on its own.
Why the Popular Fixes Fall Short
Expanding teaching residencies and loan forgiveness programs isn’t nothing — they genuinely help people who already want to teach get into the classroom. But they don’t fix a building where pay, respect, and workload are the actual reason last year’s new hire is already updating a résumé. Until those conditions change, the pipeline fixes will keep filling a bucket that’s leaking from the bottom.
Frequently Asked Questions
What’s driving the U.S. teacher shortage?
About 90% of annual new-teacher demand comes from attrition — teachers voluntarily leaving — not a shrinking pipeline of new graduates, according to the Learning Policy Institute’s July 2026 report.
How many teaching positions are affected?
At least 425,412 positions nationwide are either vacant or filled by someone not fully certified for the assignment — roughly 1 in 8 of all U.S. teaching jobs.
Which subjects have the biggest shortages?
Special education is the most widely reported shortage area, cited by 45 states, followed by science (41 states) and math (40 states).