Enrollment through HealthCare.gov for 2019 dropped less than many had predicted, due to a final surge of Americans signing up in 39 states. (Pablo Martinez Monsivais/AP)

Nearly 8.5 million Americans signed up for Affordable Care Act health plans for 2019 in the 39 states relying on HealthCare.gov — with a last-minute rush that suggests shoppers were undeterred by a federal court ruling that deemed the law unconstitutional.

The tally as of midnight Saturday was a 4 percent drop from a year ago, according to federal figures released Wednesday. The decrease from 8.8 million last year was significantly less precipitous than many had expected in light of the court decision and actions by Congress and the Trump administration to weaken the law.

After just completing its sixth annual enrollment season, the federal insurance marketplace created under the ACA “is far from dead and remarkably resilient,” said Larry Levitt, senior vice president of the Kaiser Family Foundation, a nonpartisan health policy group. He noted, however, that the number of first-time enrollees dropped by 15 percent from last year. The number of returning customers was marginally higher than last year.

For most of the six weeks of open enrollment — a shortened period adopted by the Trump administration in 2017 — enrollment was lagging by about 11 percent compared with the equivalent week last year. But the more than 400,000 who selected coverage during the final week this time actually exceeded the sign-ups during the same period last year.

The figures are not quite final, missing people who were awaiting help from federal call centers when the deadline arrived, as well as consumers in the District of Columbia and 11 states that run their own ACA insurance marketplaces and, in some cases, have later deadlines.

For the states that use the federal insurance exchange, the tally includes consumers who selected a health plan, as well as an unspecified number of current ACA customers whose coverage the government renewed automatically.

Seema Verma, administrator of the federal Centers for Medicare and Medicaid Services, which oversees much of the ACA, said Wednesday that the drop-off is a sign the Trump administration’s health-care policies are working.

In contrast to the initial chaotic year of the law’s marketplaces, when the website HealthCare.gov was dysfunctional, this year’s enrollment was “seamless,” Verma said on a conference call with journalists.

She noted that 2019 enrollment lagged behind the nation in one state, New Jersey, which rejected two of the administration’s changes to the ACA. President Trump signed a Republican tax law that eliminated the federal penalty for failing to comply with the ACA’s requirement that most Americans have insurance, and Trump health officials widened access to skimpy health plans that are cheaper because they bypass the law’s required benefits and consumer protections. New Jersey passed state laws to blunt both those changes from taking effect and still ended up with a bigger enrollment drop than the national figure, Verma said.

On Friday night, with the enrollment deadline approaching in just over 24 hours, a conservative federal judge in Texas ruled in a lawsuit by Republican attorneys general that the entire ACA was invalid. Top health aides to Trump, who has been eager to dismantle the law, responded to the ruling by U.S. District Judge Reed O’Connor by trying to reassure consumers. For now, the law’s provisions remain in place, and officials urged consumers to sign up on the final day, as usual.

Verma said Wednesday that the enrollment surge for the last day alone was milder than in previous years but noted that the fact that the deadline fell on a Saturday could have played a role.

This year and last, federal health officials have slashed the amount of money devoted to grass-roots ACA enrollment helpers, known as navigators, and to advertising and other outreach activities encouraging Americans to buy health plans. Many navigator organizations dropped out, saying they could no longer afford to do the work.

Allen Gjersvig, director of navigator and enrollment services for the Arizona Alliance for Community Health Centers, said that state’s navigator funding was cut by more than two-thirds. But on Saturday, in the hours after the Texas ruling and as the midnight enrollment deadline approached, not a single consumer asked a question about the court decision, he said.