Tex. Insurance Code § 1271.155

(a) A health maintenance organization shall pay for emergency care performed by non-network physicians or providers at the usual and customary rate or at an agreed rate.

(b) A health care plan of a health maintenance organization must provide the following coverage of emergency care:

(1) a medical screening examination or other evaluation required by state or federal law necessary to determine whether an emergency medical condition exists shall be provided to covered enrollees in a hospital emergency facility or comparable facility;

(2) necessary emergency care shall be provided to covered enrollees, including the treatment and stabilization of an emergency medical condition;

(3) services originated in a hospital emergency facility, freestanding emergency medical care facility, or comparable emergency facility following treatment or stabilization of an emergency medical condition shall be provided to covered enrollees as approved by the health maintenance organization, subject to Subsections (c) and (d); and

(4) supplies related to a service described by this subsection shall be provided to covered enrollees.

(c) A health maintenance organization shall approve or deny coverage of poststabilization care as requested by a treating physician or provider within the time appropriate to the circumstances relating to the delivery of the services and the condition of the patient, but not to exceed one hour from the time of the request.

(d) A health maintenance organization shall respond to inquiries from a treating physician or provider in compliance with this provision in the health care plan of the health maintenance organization.

(e) A health care plan of a health maintenance organization shall comply with this section regardless of whether the physician or provider furnishing the emergency care has a contractual or other arrangement with the health maintenance organization to provide items or services to covered enrollees.

(f) For emergency care subject to this section or a supply related to that care, a health maintenance organization shall make a payment required by Subsection (a) directly to the non-network physician or provider not later than, as applicable:

(1) the 30th day after the date the health maintenance organization receives an electronic clean claim as defined by Section 843.336 for those services that includes all information necessary for the health maintenance organization to pay the claim; or

(2) the 45th day after the date the health maintenance organization receives a nonelectronic clean claim as defined by Section 843.336 for those services that includes all information necessary for the health maintenance organization to pay the claim.

(g) For emergency care subject to this section or a supply related to that care, a non-network physician or provider or a person asserting a claim as an agent or assignee of the physician or provider may not bill an enrollee in, and the enrollee does not have financial responsibility for, an amount greater than an applicable copayment, coinsurance, and deductible under the enrollee's health care plan that:

(1) is based on:

(A) the amount initially determined payable by the health maintenance organization; or

(B) if applicable, a modified amount as determined under the health maintenance organization's internal appeal process; and

(2) is not based on any additional amount determined to be owed to the physician or provider under Chapter 1467.

(h) This section may not be construed to require the imposition of a penalty under Section 843.342.