There are six regional accrediting agencies to cover different parts of the U.S. For example, the New England Association of Schools and Colleges provides accreditation to schools located in the New England area. When an online college applies for regional accreditation, the regional agency that covers the home state of the college will evaluate the college. All six regional agencies are recognized by the United States CHEA or U.S. Department of Education and the Council for Higher Education Accreditation.
National accreditation is not geographically based like regional accreditation agencies are. These agencies were designed for the evaluation of specific schools and colleges. For example, a school may apply for national accreditation if the model of instruction is different from a traditional degree program. National accreditation allows trade schools, online schools and religious schools; basically all non-traditional colleges to be compared against similar institutions. The standards for evaluation and the categories for evaluation are different and will depend on the school to be accredited.
Specialized accreditation refers to program-based accreditation. It is awarded to specific departments in a college or university and to specific programs offered by a college or university. Specialized accreditation agencies represent specific fields of study and work to accredit programs rather than the entire college. For example, ABET (Accreditation Board of Engineering and Technology) accredits engineering programs offered by colleges and universities. Aspiring engineers need to ensure that the college chosen has special accreditation by the ABET but teachers, for example, will not need to worry about this accreditation.
The Carnegie Classification is not an accreditation per se; it is an independent assessment of the profile of a college. The Carnegie Foundation for the Advancement of Teaching created the classification system in 1970. It provides the framework of the grouping of American colleges and universities. The Carnegie Classification database includes all accredited degree awarding colleges in the U.S., as represented in the NCES (National Center for Education Statistics), and the IPEDS (Postsecondary Education Data System.