The lawsuit filed by House Republicans in 2014 alleges that the Obama administration was "unconstitutionally spending money that Congress had not formally appropriated" to provide subsidies for "working poor policyholders."
A district court judge in Washington, D.C. ruled in favor of the GOP lawsuit in a May 2016 decision. The ruling has since been appealed.
Anthony Wright, executive director of advocacy group Health Access California, said low-income residents in the state stand to lose an estimated $900 million in subsidies if the decision stands.
"Losing that $900 million would not just raise deductibles and copayments for hundreds of thousands of Californians, but also spike premiums and potentially crash our individual insurance market," said Wright.
Health Access California estimates that eliminating cost-sharing subsides would raise annual deductibles for someone making under 150% of the poverty level from $75 per year to $2,500 and "take a wrecking ball" to the health insurance market in the state.
'A Fine Line'
Analysts say there are limits to how far the Trump administration can go in dismantling the ACA without Congressional action.
Health & Human Services Secretary Tom Price, MD, "risks being sued for failure to implement the ACA if they go too far," said Kominski. "So there is a fine line."
The GOP can also pursue reforms to Medicaid that would cap federal funding to states but those kinds of changes would require Congressional action—something lawmakers may not wish to pursue after the defeat of the AHCA.
"Even if they can get to yes in the House, it's not clear that there is anything in the middle of the Venn diagram between the House Freedom Caucus (HFC) and the moderates in the Senate unless the HFC decides to allow almost all of the Medicaid expansion to remain in place," said Weinberg.