The great majority of federally recognized tribes in the United States have urged the Fifth Circuit to preserve portions of the Affordable Care Act specific to Native Americans, saying those provisions have nothing to do with the individual mandate a lower court found unconstitutional.

A group of nearly 500 tribes, along with many national and local tribal organizations, told the Fifth Circuit in an amicus brief on Monday that a Texas district judge failed to analyze the history and purpose of the Indian Health Care Improvement Act, the “primary, stand-alone statutory framework for the delivery of health care services to Indian people by the United States” that was included in the ACA.

The IHCIA and other parts of the ACA dealing with tribal health care “provide the foundation for an independent, freestanding Indian health care system,” and were made part of the larger law in order to fulfill the government’s trust responsibility to tribes and individual Indians, according to the brief.

“Striking down the IHCIA and other Indian health provisions on the ground that a wholly unrelated private insurance coverage mandate is constitutionally invalid would disregard those responsibilities and subvert federal Indian health care policy, without any indication that Congress had anticipated — let alone intended — such a result,” the tribes said.

In a letter to the U.S. Department of Justice on Monday, Geoffrey D. Strommer of Hobbs Straus Dean & Walker LLP, which represents the tribes, slammed the government for its March 25 brief to the Fifth Circuit arguing no part of the lower court’s judgment should be overturned.

That approach — which marked a dramatic escalation in the Trump administration’s position against the ACA — was “a gross and irresponsible violation of the federal trust responsibility to tribal nations and to American Indian and Alaska Native people, and it requires immediate corrective action,” according to the letter.

“The department’s new position … that no part of that judgment should be reversed amounts to an endorsement of the district court’s invalidation of the Indian Health Care Improvement Act and other provisions critical to the integrity of the Indian health care system,” Strommer wrote, calling for the government to tell the court that the IHCIA “must be preserved.”

In the lawsuit now before the Fifth Circuit, Texas and other states argue that the ACA’s individual mandate, which the U.S. Supreme Court upheld as a valid form of taxing, is unconstitutional following Congress’ repeal of its tax penalty in 2017, according to court filings. That repeal went into effect this year.

In their amicus brief on Monday, 483 of the 573 tribes currently recognized by the federal government, the National Congress of American Indians, Alaska Native nonprofit Norton Sound Health Corp. and many other groups didn’t take a position on the constitutionality of the individual mandate, but said that didn’t matter when it came to preserving the Indian-specific aspects of the ACA.

In his December decision, U.S. District Judge Reed O’Connor failed to analyze those portions of the law as required to see if they should be severed, and instead just threw out the entire law, according to the brief.

The IHCIA, which was originally enacted in 1976, “and other Indian-specific provisions have a separate genesis and purpose from the remainder of the ACA,” the tribes contended.

The Indian health care system, including services through the U.S. Department of Health and Human Services‘ Indian Health Service, as well as tribal hospitals and urban Indian clinics, “exists largely apart from the mainstream health care delivery system in the United States,” and “enrollment in an insurance plan is not a prerequisite for receiving direct services through Indian health care providers,” the tribes said.

Amendments to the IHCIA and related provisions were added to the ACA two days before it passed the Senate “because it was a convenient legislative vehicle — not because they were part of or related to the insurance market reforms of which the individual mandate is a part,” the tribes said.

But Judge O’Connor “did not review any of these provisions, and did not even attempt to determine whether they were in fact dependent upon the individual mandate reforms.”

“By invalidating those provisions along with the rest of the Act, the court nullified much more than was necessary to excise the effect of the individual mandate,” the tribes said. “This was error. The IHCIA and other Indian-specific provisions of the ACA are legally severable from the individual mandate, and remain valid even if the individual mandate is deemed unconstitutional.”

There’s no evidence Congress meant for the IHCIA to depend on the individual mandate when it passed the ACA, the tribes said. And when Congress passed the Tax Cuts and Jobs Act of 2017, it “chose to zero out the individual mandate tax penalty, without altering the Indian provisions or any other portion of the ACA,” according to the brief.

Strommer told Law360 on Tuesday that “the biggest flaw” in Judge O’Connor’s decision was that “he simply did not do the analysis necessary to reach a decision” on the severability of the IHCIA. Strommer added that he “wouldn’t be surprised if there are other provisions [of the ACA] that have absolutely no relationship whatsoever to the individual mandate and can stand alone without it.”

Representatives for the parties were not immediately available for comment Tuesday.

The tribes, tribal programs and tribal organizations are represented as amici by Geoffrey D. Strommer, Caroline P. Mayhew, Elliott A. Milhollin, William R. Norman and Riley F. Plumer of Hobbs Straus Dean & Walker LLP and John T. Kitchens of Norton Sound Health Corp., and by Blue Lake Rancheria General Counsel Amanda Wilbur, California Indian Legal Services Directing Attorney Mark Vezzola, Fond du Lac Band of Lake Superior Chippewa Tribal Attorney Sean Copeland, Gila River Indian Community General Counsel Linus Everling and Deputy General Counsel Thomas L. Murphy, Kalispel Tribe of Indians Senior Tribal Attorney Lorraine A. Parlange, Mississippi Band of Choctaw Indians Attorney General N. Cheryl Hamby,  National Congress of American Indians General Counsel Derrick Beetso, Navajo Nation Acting Attorney General Doreen McPaul and Assistant Attorney General Paul Spruhan, Pascua Yaqui Tribe Attorney General Laura Berglan, Red Lake Band of Chippewa Indians Legal Counsel Joseph Plumer, Rincon Band of Luiseño Indians Attorney General Denise Turner Walsh, Seminole Tribe of Florida General Counsel Jim Shore, Soboba Band of Luiseno Indians Tribal Attorney Devon L. Lomayesva, Lloyd B. Miller and Rebecca A. Patterson of Sonosky Chambers Sachse Miller & Monkman LLP, and Suquamish Tribe Attorney Melody Allen.

The plaintiff states are represented by their respective attorneys general.

The defendant states are represented by their respective attorneys general.

The House is represented by Munger Tolles & Olson LLP, the Constitutional Accountability Center and the Office of General Counsel for the U.S. House of Representatives.

The U.S. is represented by the DOJ.

The case is Texas et al. v. U.S. et al., case number 19-10011, in the U.S. Court of Appeals for the Fifth Circuit.