(NewsNation) — Roughly one-fourth of women in the United States with private insurance plans are paying for contraception, despite the Affordable Care Act mandating that such plans cover the “full range” of Food and Drug Administration-approved options.

That includes emergency contraceptives, female sterilizations and all newly approved products alongside services connected to contraception, including insertion and removal procedures and follow-up appointments.

Under ACA coverage, women with private insurance plans should not be left with a co-pay, no matter whether they have met their deductibles. But research from KFF reveals that’s not the case; insurers still make a quarter of the country’s women pay.

25% of women wrongly pay for contraception

Around 16% said their insurance plans only partially covered contraceptive costs, while an additional 6% reported the cost was not covered at all.

The KFF report also found that the 41% of reproductive-age women did not know their private insurance plans were required to cover contraception — despite the requirement going into effect more than a decade ago.

“It is completely unacceptable that plans consistently defy mandated coverage and that there is little enforcement or accountability,” Sen. Bernie Sanders, I-Vt., said in a letter to the Government Accountability Office, imploring the watch dog agency to find answers.

Newer methods aren’t included

Many women are left footing at least part of the contraceptive bill because new types of contraceptives aren’t automatically added to the list insurers work from or their requests are flat-out denied.

That includes FDA-approved Phexxi, a gel regulating vaginal acidity to prevent sperm from reaching an egg, and Natural Cycles, a smart phone app that tracks a woman’s menstrual cycle to avoid pregnancy, according to NPR.

Often, insurance companies prefer a woman use the oral birth control pill, with some being forced to try it before exploring other contraceptive options, The New York Times reported.

The Department of Labor called the “fail first” method and similar practices “unreasonable medical management techniques” and “problematic.”

A 2022 congressional investigation found the process of applying for exceptions to have contraception covered could be “burdensome for patients,” with insurance companies denying at least 40% of the request on average.

But if it’s law, how are insurance companies getting away with it? Anna Bahr, Sanders’ director of communications, told the Times “these mandates are rarely enforced, and the penalties for ignoring them are relatively low.” Rather than cover contraception as required, Bahr said the company will just invent new ways to deny coverage after each penalty.

How to get free contraceptives

File an appeal with your insurance provider if they deny you the contraceptive you want, Gretchen Borchelt, vice president for reproductive rights and health at the National Women’s Law Center, told NPR.

Borchelt emphasized that the decision is not up to the insurance company but the provider, which must comply with federal rules granting a patient the right to a contraceptive if a doctor determines it is needed for the patient.