29 U.S. Code § 1185 (a,b,f)

(a) (1) In general

A group health plan, and a health insurance issuer offering group health insurance coverage, may not—

(A) except as provided in paragraph (2)—

(i) restrict benefits for any hospital length of stay in connection with childbirth for the mother or newborn child, following a normal vaginal delivery, to less than 48 hours, or

(ii) restrict benefits for any hospital length of stay in connection with childbirth for the mother or newborn child, following a cesarean section, to less than 96 hours; or

(B)require that a provider obtain authorization from the plan or the issuer for prescribing any length of stay required under subparagraph (A) (without regard to paragraph (2)).

(b) Prohibitions

A group health plan, and a health insurance issuer offering group health insurance coverage in connection with a group health plan, may not—

(1) deny to the mother or her newborn child eligibility, or continued eligibility, to enroll or to renew coverage under the terms of the plan, solely for the purpose of avoiding the requirements of this section;

(2) provide monetary payments or rebates to mothers to encourage such mothers to accept less than the minimum protections available under this section;

(3) penalize or otherwise reduce or limit the reimbursement of an attending provider because such provider provided care to an individual participant or beneficiary in accordance with this section;

(4) provide incentives (monetary or otherwise) to an attending provider to induce such provider to provide care to an individual participant or beneficiary in a manner inconsistent with this section; or

(5) subject to subsection (c)(3), restrict benefits for any portion of a period within a hospital length of stay required under subsection (a) in a manner which is less favorable than the benefits provided for any preceding portion of such stay.

(f) Preemption; exception for health insurance coverage in certain States

(1) In general

The requirements of this section shall not apply with respect to health insurance coverage if there is a State law (as defined in section 1191(d)(1) of this title) for a State that regulates such coverage that is described in any of the following subparagraphs:

(A) Such State law requires such coverage to provide for at least a 48-hour hospital length of stay following a normal vaginal delivery and at least a 96-hour hospital length of stay following a cesarean section.