Obtain a General Education Diploma (GED). The GED test is an option for individuals who do not have a high school diploma. Passing the GED test is considered the equivalent of a high school diploma by most colleges, universities, job-readiness programs and vocational schools. To earn a GED, an overall passing score as well as a passing score is required on each of the five parts -- math, science, reading, writing and history.
If you do not have a diploma, consider two-year colleges or online schools. Many community colleges are more accustomed to accommodating students who have not earned a high school diploma and have been out of school for a while. Some online schools will even allow students to work toward a college degree and high school diploma at the same time.
Research services for non-traditional students. Many colleges and universities offer special services for non-traditional students, allowing them to bypass typical standard requirements such as a high school diploma or an SAT score. The student usually must demonstrate that she can handle the demands of college to be accepted. These services vary at each school.
Speak with the school's admissions counselor about taking a college placement test. These tests can qualify you for enrollment. If you pass the placement test, the school may decide to admit you whether you have obtained a high school diploma or not.