The Affordable Care Act ensures that all FDA-approved birth control methods are covered without a copay if you have health insurance, with few exceptions.

But the revised Senate health care bill would scrap the birth control mandate — allowing insurance companies to sell plans that don’t include any of the currently mandated women’s preventive health services, from birth control to HPV testing.

This change is part of a broader rollback of preventive benefits: If the Senate bill becomes law, health insurers will be able to offer plans that don’t cover a range of these services, from cancer screenings to childhood immunizations. Under the Affordable Care Act, all insurers are required to cover them.

Insurers would have to sell at least one comprehensive plan that complies with all the Obamacare-era regulations. But as long as they did that, they could also sell skimpier, cheaper plans, including ones that exclude women’s preventive care.

This is a new development in the Senate health bill, based on a proposal by Sen. Ted Cruz (R-TX). The original draft of the Better Care Reconciliation Act allowed for states to waive the requirement that insurers cover essential health benefits — including emergency or maternity care; preventive care was covered in a different part of the bill, and therefore the birth control mandate was left untouched.

The revised Senate bill, though, lets some health plans opt out of Section 2713(a) of the Public Health Service Act, which under the Affordable Care Act mandates that insurance plans cover preventive health care. The Obama administration interpreted this section to require the coverage of contraceptives.

In May, Vox’s Sarah Kliff reported that the Trump administration was considering weakening the birth control mandate by giving employers a path to opt out based on moral or religious considerations. The Senate bill would go even further by getting rid of the requirement that insurers cover birth control (and other preventive care, for both men and women) entirely.

Ultimately, the BCRA creates a two-track system for health care coverage, offering both bare-bones options and more comprehensive plans, which would disproportionally benefit healthier and wealthier Americans while disadvantaging lower-income sicker Americans, as Kliff explained:

One would offer cheaper, deregulated health plans, which healthy people would likely flock to. The other would include comprehensive plans governed by Obamacare’s regulations, which would cost more and mostly be used by less healthy people and those with preexisting conditions — a system experts expect would function like a poorly funded high-risk pool.

The Senate health bill already reduces access to women’s health care — particularly for low-income Americans — through defunding Planned Parenthood, which provides many of these preventive services, and making drastic cuts to Medicaid, which currently covers half of all US births, as Vox’s Julia Belluz has written.

Obamacare’s regulations expanded access to contraception for millions of American women, both for family planning and for other health concerns, like endometriosis, which birth control is often used to treat.

This new revision would be a drastic reversal of that effort.