An intrauterine device (IUD), also known as intrauterine contraceptive device or coil, is a small, often T-shaped birth control device that is inserted into the uterus to prevent pregnancy. IUDs are one form of long-acting reversible birth control (LARC). One study found that female family planning providers choose LARC methods more often (41.7%) than the general public (12.1%). Among birth control methods, IUDs, along with other contraceptive implants, result in the greatest satisfaction among users.

Long-acting reversible contraceptives (LARC) are methods of birth control that provide effective contraception for an extended period without requiring user action. They include hormonal and non-hormonal intrauterine devices (IUDs), and subdermal hormonal contraceptive implants. They are the most effective reversible methods of contraception because their efficacy is not reliant on patient compliance. The failure rates of IUDs and implants is less than 1% per year.