The Trump administration's move fueled accusations that it was politicizing the Justice Department, which is supposed to defend the constitutionality of federal statutes in court - even if the administration in power does not like them - if reasonable arguments can be made.
The filing declares unconstitutional the so-called individual mandate-which requires nearly all Americans to purchase health insurance or pay a "tax" if they don't-and calls for several elements of ACA to be invalidated.
It said that the requirement that people have health insurance - the individual mandate - was unconstitutional and that the entire law, including provisions that guarantee access to health insurance regardless of any medical conditions, should be struck down as a result. The Justice Department reportedly also wants to repeal limits on insurance costs based on gender and age. But in this instance it agrees with the state that the individual mandate and other requirements should be deemed illegitimate as of January 1, 2019. Cortez ScottBishop from royal wedding marches to White House Bishop from royal wedding to march against "America First" policies in DC Supreme Court upholds agreements that prevent employee class-action suits MORE (Va.), Frank Pallone Jr. But under the GOP tax bill signed into law last December, tax penalties for people without insurance were eliminated.
The Justice Department thus claims that the individual mandate is unconstitutional as of January 1.
These sections of the law, along with the mandate that insurers provide comprehensive coverage, are the bedrock of Obamacare's protections for those with pre-existing conditions.
A coalition of 20 US states sued the federal government in February, claiming the law was no longer constitutional after last year's repeal of the penalty that individuals had to pay for not having insurance.
What do other states say?
California and 15 other states also filed a brief Thursday to intervene and defend the ACA and its consumer protections. A definitive court ruling "could be months away" according to The New York Times, with appeals lasting many more.
But it said the rest of the law, including Medicaid expansion, can remain in place.
Some 70% of folks said the federal government should continue prohibiting insurers from charging more to those with pre-existing conditions, according to a Kaiser Family Foundation poll from June 2017.