Private schools are usually able to determine their own teacher qualifications because they are not state funded. Typically, they will require a college degree in a relevant subject (e.g., if you have a Bachelor of Arts degree in English, you might apply to teach English). Some private schools may be stricter in their employee qualifications than public schools, while others may be more lenient. It can vary from school to school because each is independent. Public schools, however, will be consistent throughout a state in their requirements, as determined by the board of education.
If you know where you will be living or teaching, at least initially, your best bet is to get the certification information for your particular state. Go to your state government's website, and find the teacher certification requirements. Most state websites have a handy checklist of necessary certification requirements. In the case of Washington state, the basic requirements are a bachelor's degree, a recognized teacher training program (a list is approved programs is included) and a passing grade on a teacher skills test.
Virtually without exception (see the next section), you will have to complete at least one college degree and probably some additional education in order to be a licensed teacher. If you go to college in the same state where you plan to get your certification, odds are your school's teacher training program will be recognized by the state. The education programs at the University of Alabama in Huntsville, for example, are approved by the state of Alabama. But if you're planning on attending school in Alabama but teaching in Kentucky, speak to a student advisor in the education faculty or someone at the licensing board in Kentucky to make sure your program meets requirements.
Teacher training is often offered through a master's degree program, thus falling under graduate studies. Admission requirements vary from school to school but may require a minimum undergraduate GPA and certain required courses. If you're thinking of going into education, determine your admission requirements now, so you don't have to make up compulsory courses later.
Virtually all states have provisions for a situation wherein a qualified candidate cannot be found. State licensing boards can issue emergency teaching licenses to individuals who do not meet the normal educational requirements. These licenses are normally temporary, and the deficient credentials must be made up within a set period in order for the certification to be made permanent. If you know you want to teach, you should meet the requirements for a regular professional teaching certification for your state.
You may teach outside the public school system and therefore not require state certification. This could include private schools or instructor positions at small colleges, which may require only a university degree. Additionally, instructor positions for private language instruction, music instruction and athletics instruction may have their own requirements and may involve instructing in these subjects privately, through a small business or through a community club.
Many foreign countries also look for native English speakers, especially Americans, to teach English as an additional language. Depending on the job, you may require a college degree or TESOL training.