Frelinghuysen, 71, has represented New Jersey’s eleventh district for over 23 years.
Several of his colleagues have cited committee chairmanship term limits as a reason for their retirement this year, but Frelinghuysen would have been eligible to remain chairman of the powerful House Appropriations Committee until 2023.
President Donald Trump won the district, which is located in northern New Jersey, by only one point in 2016.