The Obama administration is cracking down on health insurers that have violated the Obamacare mandate requiring them to cover birth control at no cost to patients.

In new regulations, the administration clarified that insurance plans must cover all FDA-approved forms of birth control, including the pill, the patch, IUDs, and sterilization. Recent investigations have shown that some health plans were not doing this; for example, some would not cover the patch and would ask patients to use birth control pills instead.

Obamacare requires insurers to cover birth control without any cost to the patient

Obamacare requires health insurance plans to cover all FDA-approved contraceptives without any cost to the patient.

While birth control is often used as shorthand for hormonal birth control pills, in the case of the health-care law, it refers 18 types of contraceptives that the FDA has found to be safe and effective. This includes but is not limited to oral contraception (a.k.a. the pill), birth control patches, the ring (otherwise known as Nuvaring), the shot (Depo-Provera), IUDs (intrauterine devices), and permanent contraceptives like sterilization.

The birth control mandate means insurance plans cannot charge co-payments when patients fill any birth control prescription, whether that's for birth control pills, an IUD (which can cost as much as $1,000), or something else.

Insurers used a loophole to avoid covering some birth control products

Two recent investigations — one by the Kaiser Family Foundation and another by the National Women's Law Center — found that not all insurance plans were abiding by these rules.

Some insurers seemed to blatantly disregard the Obamacare mandate. The KFF study — which looked at a sample of 20 insurers in five states — found one that simply didn't cover the birth control ring and four that "couldn't ascertain" whether they covered birth control implants. These are potential violations of the law.

What was more common, however, was insurers using something called "reasonable medical management." This is where insurers restrict access to certain medications when they think there might be a cheaper, equally effective way for patients to get the same treatment — and this did seem to be legal under the health law's birth control mandate, until now.

This tactic seems to be especially prevalent with birth control patches and rings. These contraceptives use the same hormones as pills. And they have a slightly worse failure rate than the pill. On these contraceptives, 9 out of 100 women using them will become pregnant within a year, versus a 6 percent failure rate with the pill.

The pill has another advantage over the patch and the ring, too: it tends to be slightly cheaper. So the KFF study finds that some plans are limiting access to rings and patches, offering the pill as an equally effective option.

One insurer that KFF talked to said it "cover[s] a birth control pill with no cost-sharing and therefore charges cost-sharing for the NuvaRing, which has the same chemical composition." Another insurer charges cost-sharing and requires enrollees to "show medical necessity on why oral contraceptives are not suitable before they will cover the NuvaRing."

The Obama administration's new order: cover all birth control types

In new guidance released May 11, the Obama administration essentially said this type of reasonable medical management is illegal — that the mandate in Obamacare ought to be interpreted as requiring insurers to cover every type of birth control.

This does not, however, mean that insurers have to cover every single birth control product approved by the FDA. The new guidance does give them leeway to limit coverage to certain products so long as they cover all contraceptive types.

For example: an insurance plan cannot deny a woman coverage for a birth control patch and ask her to use pills instead. This new guidance makes that flatly illegal.

What it can do, however, is only offer coverage for the generic birth control patch and refuse to pay for the brand-name one.

Overall, reproductive health advocates were pleased with the new guidance, which they think will better protect women's access to care.

"It is past time for insurers to adhere to the law and stop telling women that their chosen method isn’t covered or that they must pay for it," Gretchen Borchelt, vice president for reproductive rights at the National Women's Law Center, said in a statement. "We welcome the Administration’s guidance and know it will go a long way to improve the health and economic well-being of women and their families."