WASHINGTON — The Education Department is announcing $28.4 million in grants to 38 states, Washington, D.C., and the Virgin Islands to reduce costs of advanced placement exams for low-income students.

Education Department Delegated Deputy Secretary John King said the grants help to eliminate barriers for “historically underserved students” including African-American and Latino students.

Some students could pay as little as $12 for an exam. Without the grants, some tests cost nearly $100.

The grants help pay for tests administered by the College Board, the International Baccalaureate Organization and Cambridge International Examinations.

The department said the reduced costs will encourage students to take placement tests and obtain college credit for high school courses, reducing time and costs for a postsecondary degree.

The department offset costs for nearly 832,000 during the 2014-2015 school year.