In the United States, there are public, private, and charter college preparatory schools and they can be either parochial or secular. Admission is sometimes based on specific selection criteria, usually academic, but some schools have open enrollment. Fewer than 1% of students enrolled in school in the United States attend an independent, private preparatory school, compared to 9% who attend parochial schools and 88% who attend public schools. Public and charter college preparatory schools are typically connected to a local school district and draw from the entire district instead of the closest school zone. Some offer specialized courses or curricula that prepare students for a specific field of study, while others use the label as a promotional tool without offering programs that differ from a conventional high school. The term "prep school" in the U.S. is usually associated with private, elite institutions that have very selective admission criteria and high tuition fees, catering to students in the 13 - 18 age range. Prep schools can be day schools, boarding schools, or both, and may be co-educational or single-sex. Currently day schools are more common than boarding, and since the 1970s co-educational schools are more common than single-sex. Unlike the public schools which are free, they charge tuition. Some prep schools are affiliated with a particular religious denomination. Unlike parochial schools, independent preparatory schools are not governed by a religious organization, and students are usually not required to receive instruction in one particular religion. While independent prep schools in the United States are not subject to government oversight or regulation, they are accredited by one of the six regional accreditation agencies for educational institutions.
In Japan, college-prep schools are called "yobikou", which literally means a school used to progress into another school. Prep schools in Japan are usually considered prestigious and are often difficult to get into. However, there are many tiers of prep schools, the entry into which depends on the university that the school leads into. Japanese prep schools started as "chu-gakkou", secondary schools for boys, which were founded after the secondary school law in 1886. Later, "koutou-jo-gakkou", secondary school for girls, and "jitsugyo-gakkou", vocational schools, were included among "chutou-gakkou" and were legally regarded as schools on the same level as school for boys, but graduates from those two types of schools had more requirements on college entrance. In the modern period, many Japanese secondary schools were five-year schools except for during a short term from 1943 to 1946. The social status of "chu-gakkou", or "kyusei chu-gakkou", secondary schools for boys under the old system, didn't disappear even after the new system took effect in 1947. Plenty of "shin-gakkou" are six-year schools these days, and many of them have their origins in "kyusei chu-gakkou" and "kotou jo-gakkou", or ones attached to universities. Japanese pupils who aspire to a prep school education take written examinations when they are in sixth grade in each prep school. Other than six-year prep schools, the top municipal senior high school in each school zone and some high-ranked private senior high schools are also regarded as "shingaku-kou". In the 21st century, some trial cases that connect public junior and senior high schools are seen in each region, too, which broadens education for college entrance. As Japanese government provides grant-in-aid to private schools, the tuition is 5,000–10,000 US dollars per year even if it is a private school.