An Institute of Medicine panel recommended insurance companies cover contraception without copayments.
Contraception - along with such care as diabetes tests during pregnancy and screening for the virus that causes cervical cancer - was one of eight recommended preventive services for women.
"Unintended pregnancies carry health consequences for the mother - psychological, emotional and physical - and also consequences for the newborn," said Dr. Linda Rosenstock, panel chairwoman and dean of public health at the University of California, Los Angeles. "The overwhelming evidence was strongly supportive of the health benefit" of contraception.
Medical experts say easier access could start a shift to more reliable forms of long-acting birth control, such as implants or IUDs. Emergency contraception, known as the morning-after pill, would also be covered.
The Health and Human Services Secretary Kathleen Sebelius called the recommendations "historic," saying they are based on science. She is expected to make decision by Aug. 1.
The recommendations will become effective for insurance plans a year after the final decision is posted.
The Associated Press contributed to this story.