Schools need effective and well-prepared teachers, especially in areas where there are high concentrations of students with high needs.

This lesson explains the messy processes and rules that determine who works where in California schools. It explores the power that teachers have (and lack) to choose where they work, and answers the question why so many teachers never move. This lesson also explains the basics about substitute teaching — and what happens when the regular teacher isn’t there.

Push and Pull in teacher assignments

Teachers are employed by school districts, not by schools. Every class needs a teacher, and it's a big logistical challenge, even in small schools. Districts can take a mix of two main approaches to determine where their employees work and the classes they teach: push and pull.

• Push approaches directly assign teachers to schools and classes. Teachers don't love being told where they have to work. Push policies often require collective bargaining agreements that provide the district with sufficient discretion to make assignments.
• Pull approaches give teachers more control over which school they work in and the classes they are assigned to teach. In this model, some districts use incentives to attract teachers to choose more-challenging assignments. Such incentives include promises about working conditions, recruitment of a strong school leader, arrangements to move teachers as a group, reduced or flexible work assignments, and (sometimes) increased compensation. Pay matters; school districts use pay incentives to attract teachers to apply for open positions.

California laws about school assignments are complex. It can be challenging for a district to change a teacher assignment if the teacher objects.

How do teachers switch schools?

Teachers in California public schools are employed by school districts or by charter schools (LEAs). Within a big district, teachers can negotiate a move from one school to another without changing their employer, usually with the cooperation of the school leaders affected. To move to a school in another district is considerably more complicated, because it involves leaving your job and signing a new contract with a new employer. This means relinquishing your seniority, which can imply a pay cut. This is part of the reason teachers tend to stay put.

What is student mobility?

Funding for education in California is based on school attendance, as Ed100 Chapter 8 will explain. School districts decide how many teachers to employ in each school based on the number of students that they expect will attend. In places where there is high student mobility — that is, where families are more likely to relocate during the school year — this can be a tricky business. California began making historical data available about mobility and stability in 2021.

In general, districts plan the number of teachers at a site based on a ratio of students and teachers. This ratio doesn't generally take teacher experience into account, which can create unintended consequences.

Inexperienced teachers earn lower wages than experienced ones, so a school with many inexperienced teachers has low average staff costs.

Because inexperienced teachers earn lower pay than experienced ones, a school with a large percentage of inexperienced teachers has low staff costs. Conversely, schools with lots of experienced teachers have high true costs. This is not always obvious. Under federal law (ESSA Title I), districts must allocate state and local funds to schools using a method that doesn’t penalize a school because it receives federal Title I funds.

The SARC report

In California, information about actual staff costs at the school site level can be hard to find. The School Accountability Report Card (SARC) is a dense document full of useful information for those intrepid few who actually find it and read it. SARCs are collected by the state, but the locally reported information they contain is not systematically reviewed for accuracy or quality. (Yes, this is bad, but it still represents some progress. Until the passage of the Federal ESSA law at the end of the Obama Administration, there was almost no way to get this information — it was a completely hidden area of inequity in school systems. This issue is explained in greater depth in Ed100 Lesson 8.7.)

How often are teachers absent?

According to data from the National Center for Teacher Quality, teachers miss work an average of about 9.4 days per school year, but the rate varies significantly among districts and data are not easy to find. Teacher absences can involve training days, conferences, sick leave, personal days, and absences for other reasons — or no reason at all. Expectations about teacher absences can become part of the culture of a district, intentionally or otherwise. On a typical day, about three to six percent of teachers are absent.

Some teacher contracts accidentally encourage teacher absences with "use 'em or lose 'em" clauses that blur the use of vacation days and sick leave. The cost of covering for a teacher's absences is a hidden area of compensation. A major study of teacher attendance in 2012 estimated the cost at about $1,800 per teacher per year (at least $2,600 in 2026 dollars), again with big variances.

Students spend a surprising amount of their education with substitute teachers. Over the course of a K-12 education, an average student will cumulatively spend more than half of a school year being taught by substitute teachers.

When teachers are absent, student learning tends to suffer, but what happens in the teacher’s absence matters. Some substitutes are considerably more effective than others, and continuity helps.

How do people become substitute teachers?

As explained in Lesson 3.1, California has a persistent shortage of people who want to work as teachers. The shortage is even more acute for substitute teachers.

It is very easy to qualify to work as a substitute teacher in California. You must have earned a four-year college degree, and there's some minimal paperwork involved, but the state doesn't require a full credential. Districts have the power to set their own requirements. Despite its name, the 30-Day Permit can be used throughout the school year; the usual limit is 30 days substituting for any one teacher, or 20 days in a special education classroom.

Most substitute teachers are paid by the day, and the rate can vary wildly from one substitute "gig" to the next. In October 2026 many job listings for substitute teachers on EdJoin offered more than $400 per school day in San Francisco. Districts have some practical incentives to re-hire the same substitutes repeatedly, if they can. Districts often try to maintain a pool of candidates so that when a teacher calls in sick there's a clear list of people to call. Substitute teachers don’t have to accept every job offered to them. Schools with a reputation for treating substitute teachers well have a significant advantage over those with a poor reputation.

When no substitute is available, students still need supervision. Lacking better options, administrators can find themselves serving as costly stand-ins. Teachers can also cover for one another by sending otherwise unsupervised students to other classrooms.

Last updated October 2026.