Which brings me to the final ambiguity. The manager’s amendment retains almost the entirety of the ACA’s rule governing the essential health benefits. The Secretary of HHS is still required to “define the essential health benefits,” which must include the ten major benefit categories, including maternity care and mental health services. Plus, the Secretary must “ensure” that the scope of the essential health benefits is “equal to the scope of benefits provided under a typical employer plan.”

The amendment just tacks on a provision saying that, for 2018 and beyond, “each State shall define the essential health benefits with respect to health plans offered in such State.” That’s all the provision says; it doesn’t elaborate. So do these state-defined essential health benefits also have to cover the ten categories of benefits? And do those benefits have to be the same as those in a “typical employer plan”?

The amendment doesn’t say. It’s probably best understood to give states carte blanche to define essential health benefits. The ten categories and the typicality requirement would then apply only to the HHS Secretary’s definition, not to the states’ definitions.

But that’s not the only way to read the amendment. It’s also possible to read it as shifting responsibility for defining the essential health benefits from the Secretary to the states. On that view, states would have to adhere to the same rules that govern the Secretary’s definition. Maternity care and mental health services, among other benefits, would still have to be covered. Typicality would be preserved.