Teachers in American public schools are required to hold or obtain a teaching license or certificate.

The terminology varies from state to state, but there are two main tracks that teachers follow to achieve licensure:

Traditional Route describes the pathway into the profession of students in approved teacher preparation programs (undergraduate or graduate) who gain their student-teaching experience in the course of studying for the degree. Many states will only issue a permanent or full certificate after a probationary period in the classroom, but traditional-route candidates are generally eligible to be hired for any teaching position in their content area. 

Alternate Route describes a variety of state-level programs which may allow certain individuals to begin teaching without a license. Alternate-route candidates must have earned a college degree and may be subject to other requirements as well: a certain number of credits in a particular content area, for example, or achieving a threshold score on a standardized exam like the Praxis. During the first year of service, alternate-route teachers receive mentoring and take classes (sometimes but not always for graduate credit) that prepare them for permanent licensure, which is also contingent on successful evaluations from supervisors.

The alternate route has become increasingly widespread in recent years as enrollment in traditional-route programs has declined. Many states with fast-growing populations have experienced teacher shortages and sought to fill them by relaxing pre-service requirements, especially in high-demand areas like mathematics and science. At the same time, though, even thorough mastery of a particular content area does not always translate immediately into skill in motivating students, organizing units of instruction, or explaining difficult concepts.

Generally, teaching licenses are only valid for particular kinds of jobs: elementary education, special education, and secondary school specialties like language arts or mathematics, for example. Because the certification of teachers is regulated on a state level, moreover, a teaching license issued in one state is not automatically valid in others. However, in recent years many states have negotiated reciprocity agreements to simplify and standardize the process. An overview of state licensure and reciprocity can be found at the website of the Education Commission of the States.

Regional State Licensure Requirements

Most states provide copious online documentation about policies and procedures related to licensure.