The average price for the most common type of health insurance sold through the Affordable Care Act’s federal marketplace will drop by about 4 percent for next year, extending a reversal of steep rate increases that daunted in its early years.

The second consecutive year of lower monthly premiums coincides with a significant improvement in the number of insurance companies selling ACA health plans. Just 12 percent of ACA customers live in counties that will have only one insurer in the marketplace for the coming year, compared with almost 30 percent for 2018, and more than two-thirds will have a choice of at least three companies.

This brightening scenario for Americans buying such health insurance creates awkward conflicting messages for senior Trump administration officials who on Tuesday presented the statistical picture of the ACA marketplaces before the seventh annual enrollment season opens late next week.

Health and Human Services Secretary Alex Azar and Centers for Medicare and Medicaid Services Administrator Seema Verma persisted in tarring the system of individual insurance created under the health-care law as unwieldy, unaffordable for too many and in need of replacement. They also praised President Trump’s guidance for making the law’s insurance exchanges work better.

“The president who was supposedly trying to sabotage the law has been better at running it than the guy who wrote the law,” Azar said during a phone briefing for reporters, alluding first to Trump and then to his predecessor, President Barack Obama, who regarded the ACA as one of his main domestic accomplishments.

A pro-ACA organization, made up largely of Obama-era health officials, derided Azar’s characterization. “The [current] administration deserves zero credit for the success of the ACA,’’ said Leslie Dach, chair of Protect Our Care, contending that Trump’s policies were causing more people to be uninsured.

The marketplaces were created under the ACA for people who cannot get affordable health benefits through their jobs. The 4 percent price drop is not for everyone; it is the average for premiums in 2020 for the popular level of coverage on which federal subsidies are based. The figure is calculated for both a typical 27-year-old and for a family of four. This premium drop comes after a smaller decrease for 2019.

The rates announced Monday are for the 39 states that are in the federal insurance marketplace or rely on the government’s computerized enrollment system. The other states and the District of Columbia operate their own insurance marketplaces under the ACA.

In the Washington area, Virginia is the only state using, and the average premium there will decrease by 6 percent, according to federal data, which shows that rates are going down in 27 of the states included in the analysis.

The data also shows that the number of insurance companies willing to sell ACA health plans has rebounded after widespread defections for a few years. Early in Trump’s time in the White House, health officials often pointed to departing insurers as evidence that the law was failing.

Verma, the CMS administrator, told reporters that the administration has taken steps to appeal to insurers, such as making it more difficult for consumers to sign up for health plans outside of the annual enrollment season.

Neither she nor Azar addressed the reason behind falling insurance prices, but they repeated an administration refrain that premiums are unaffordable for Americans whose incomes are slightly too high for them to qualify for the premium subsidies the law provides. Some ACA proponents have contended that premiums rose higher than necessary early in Trump’s tenure after he eliminated a type of subsidy for insurers, so the rate decreases lately have been seen as a sort of correction.

ACA health plans first became available for 2014, four years after Congress passed the sweeping law that revised large parts of the U.S. health-care system. During the first enrollment period, which started in the fall of 2013, debuted with computer defects so severe that many people could not sign up for coverage, but the bugs eventually were corrected, and the past few enrollment periods have been relatively smooth.

Since Trump took office, the larger impediments, critics say, have been steps his administration has taken to try to thwart the ACA.

Federal health officials have, for instance, slashed federal money that has paid for “navigators” — experts from nonprofits who helped consumers figure out how to sign up for coverage. The administration also has nearly eliminated funds for advertising and other outreach activities focused on hard-to-reach people who are eligible for ACA health plans but remain uninsured. Verma has repeatedly said that neither form of help was particularly useful.

In addition, a central requirement of the law — that most Americans carry health insurance — was neutralized starting in January because recent tax changes, passed at the end of 2017 by a Republican-led Congress and signed by Trump, eliminated the financial penalty for people who flouted that requirement.

Still, despite predictions of ACA supporters that such moves would reduce enrollment, the draw of the marketplaces has remained fairly sturdy. According to the most recent federal figures, 10.6 million consumers had ACA health plans as of early this year — a decline of less than 1 percent from a year before.

In contrast with the Obama years, Verma told reporters that the administration once again has not produced a forecast of how many consumers will sign up for coverage for 2020, even though the Government Accountability Office last year urged HHS to do so.

The next sign-up period, Nov. 1 through Dec. 15, comes as a New Orleans-based federal appeals court is expected to issue its opinion soon in a lawsuit challenging the ACA’s constitutionality. Asked whether a ruling against the law, as the administration has urged in the case, would dissuade people from enrolling, Azar predicted that it would not.

“Our message would be keep calm and carry on,” Azar said, noting that the court’s opinion almost certainly would be appealed to the Supreme Court. “There will be no immediate disruption to anybody.”