If you are sick and in need of health insurance, you’d be well advised to get it quickly. The Affordable Care Act (ACA) is once again in legal jeopardy, along with its protections for those with preexisting medical conditions.

A year ago, a federal judge in Texas ruled that the entire law must be struck down because its mandate to obtain insurance is unconstitutional. The decision was appealed, and this week, an appeals court agreed that the mandate must go. It asked the lower-court judge to revisit the question of how much of the rest of the ACA can remain, but he has already indicated where he stands on the issue. (To read the full opinion, click here.)

The reasoning of both courts was that the mandate lost constitutional protection when the penalty for noncompliance was set at zero by Congress in 2017. How, you might wonder, can a mandate that was constitutional when it included an enforcement penalty become unconstitutional when the penalty has disappeared, and it has become unenforceable? The line of reasoning is that the penalty had been upheld as a tax by the Supreme Court in 2012, but with money no longer involved, it can no longer be seen as a form of taxation.

The argument makes no sense. The Supreme Court characterized the penalty as a tax because you are in compliance whether you choose to pay it or to receive an exemption by maintaining the required coverage. With the penalty set at zero, everyone is automatically in compliance, even if they do not maintain coverage. For all practical purposes, the mandate no longer exists.

But nonsensical or not, the threat to the ACA is real under this latest ruling. The final call will probably be made by the Supreme Court, and it is too early to tell which way the justices are likely to rule or when the the case will go before them. Supreme Court review could come as early as this spring, or the case could drag on for years while the ACA’s fate remains uncertain.

At this point, any legal outcome is theoretically possible. The ACA could continue minus only the mandate, which it has been doing successfully for the last two years. Or, it could continue minus the mandate and the protections for those with preexisting conditions. Or, it could continue without some of its other provisions. Or, it could entirely disappear.

Losing the entire ACA would create chaos throughout the health-care system. It could also undermine the integrity of the legal system, since courts would have succeeded in overturning a major piece of legislation without a coherent justification. Of course, neither outcome seems to concern the law’s opponents or the judges who have most recently ruled against it.

So, if you rely on the ACA for health insurance, especially if you have a preexisting medical condition and can’t find coverage elsewhere, you have reason to be concerned. For the time being, the law will remain in place while the case works its way through the courts. However, the law’s opponents remain relentless in their efforts to undermine it, regardless of the consequences.

Robert I. Field is a member of The Inquirer’s Health Advisory Panel and a nationally known expert in health-care regulation and its role in implementing public policy. He holds a joint appointment as professor of law at the School of Law and professor of health management and policy at the School of Public Health at Drexel University.