By the close of Obamacare's first open enrollment in mid-April, the federal government was crowing about how many people had signed up via the HealthCare.gov insurance exchange that it operates.
But nearly four months later, the federal government remains mum on several key questions about that online marketplace, which sells coverage in 36 states, and was built with hundreds of millions of dollars in taxpayer funds.
In sharp contrast to HealthCare.gov, the 15 health insurance exchanges run by individual states and the District of Columbia are, as a group, much more forthcoming with answers when asked those same kinds of questions.
The questions that the U.S. Health and Human Services Department wouldn't answer when asked by CNBC.com were:
HHS also would not disclose the premium rates that insurers have proposed to charge for their 2015 plans, which go on sale at HealthCare.gov when Obamacare's second enrollment season begins Nov. 15.
The department noted that although some of the 36 states it serves do disclose such information via their insurance regulators, the majority don't.
In a email response to CNBC, HHS spokesman Aaron Albright suggested that all of the information requested would be disclosed in the future, but he would not specify a date.
"HHS issued monthly enrollment reports during the first marketplace open enrollment period in order to provide the best understanding of enrollment activities as it was taking place. Now that this time period has ended, we are looking at future opportunities to share information about the marketplace that is reliable and accurate," Albright said.
"For instance, we are releasing monthly reports on Medicaid enrollments, recently released a state-by-state analysis of premiums paid by consumers and a brief on those taking advantage of preventive screenings under the Affordable Care Act, among others. As we have previously stated, we look forward to releasing additional information later this year on those who have paid their premiums."
Conversely, at least 12 out of the 15 state-/D.C.-run exchanges have disclosed their respective enrollment per insurer, according to a survey done by CNBC.
And at least 10 of those exchanges have disclosed, at some point, how many people have paid their first month's premiums.
For example, a spokeswoman for Colorado's exchange, in a statement to CNBC, said: "As of June, we received data from the health insurance carriers that show 89.9 percent of Coloradans who purchased private health insurance through Connect for Health Colorado paid their first-month premium. There is some lag in data, so we anticipate that percentage may actually be higher ... we obtain this data from each of our 17 carriers and anticipate more complete information as we move forward."
At least 11 states are either regularly releasing information about the special enrollment tallies or will provide such information when asked.
And the proposed premium rates for next year's plans on 12 of those 15 exchanges are publicly available, usually from the state's insurance regulator.
One state-run exchange, Covered California, held a press conference last week to publicly reveal the proposed rates for that marketplace, which sells more Obamacare plans than any other in the U.S.
Bethany Frey, a spokeswoman for Washington state's Obamacare exchange, said, "We just think it's important to share" the information that CNBC had requested.
"We know that people are interested in the data," said Frey, whose state's exchange, along with that of Massachusetts, is one of just a few to report enrollment only if someone has paid for their plan.
The federal government's lack of transparency on these questions has irked Obamacare supporters and critics alike.
It also has raised questions about whether the Obama administration is withholding answers to questions—particularly about HealthCare's "paid rate" and how much premiums will rise in 2015—because of fear that information could hurt Democratic candidates in the this fall's congressional elections.
"The self-proclaimed 'most transparent administration in history' has failed to shoot straight with the American public [and is] reluctant to share any meaningful or relevant information regarding the president's health-care law from the get go," said Rep. Bill Cassidy, R-La.
"There is no doubt that if there were positive news to spread, the administration would take to its megaphone and shout it from the rooftops, but the sad reality is that this law has led to canceled plans, fewer choices, higher costs and limited access to doctors," said Cassidy, who is a medical doctor. "The law was built on the president's broken promises, and the White House has been focused on damage control ever since. The American people deserve to know the facts, especially when it involves their personal health-care options and potential costs."
Caroline Pearson, vice president of health reform at the consultancy Avalere Health, said the federal government could "quickly" get the answers to the questions that CNBC posed from insurers, even if that information is not immediately at hand.
"There is clearly a political motivation" in the failure of HHS to release either the paid rate or the proposed premiums for 2015, Pearson said.
"The federal government is trying to manage the message to the best of their ability in anticipation of midterm election," she said. "There has certainly been a strategy from the administration of very tightly managing the message by not releasing the more substantive data points that people want."
The paid rate has been one such bit of data.
For weeks last spring, after HealthCare.gov began enrolling substantial numbers of people on the heels of significant repairs to that website, Republican critics of Obamacare suggested that the number of people who would actually pay their first premium would be much lower.
Individual insurers and surveys soon suggested that the paid rate was, on average, between 80 to 90 percent, which is consistent with what was seen in the individual insurance market pre-Obamacare.
But even if that rate is within industry norms, it presents a potential public relations problem for the Obama administration.
"They did a huge amount of publicity about getting 8 million people in," said Pearson, referring to the total number of sign-ups on both HealthCare.gov and the 15 other state-run exchanges by the close of open enrollment in mid-April.
"That's the talking point they want to persist in the environment," she said. "They do not want to undermine the victory of 8 million in by saying '15 percent or more didn't pay.'"
She also noted that the administration, which originally planned Obamacare's second open enrollment to begin this coming Oct. 15, moved it so it will now start Nov. 15—nearly two weeks after the congressional elections. That means that people shopping for Obamacare plans, or looking to renew existing coverage, will not likely be aware of the final approved premium rates for 2015 until after they've voted.
Even when they might have some good news to tell, HealthCare.gov's operators are keeping quiet.
In particular, the administration is not releasing data on how many people have been signing up during the ongoing special enrollment period.
Charles Gaba, a website developer whose Obamacare enrollment-tracking blog ACASignups.net has become a key resource for health-care media, is estimating that by the second week of August, total sign-ups should reach 9 million nationwide—nearly 1 million more since the close of open enrollment.
Gaba's estimates of nationwide sign-up totaling between 8,000 to 10,000 per day are based on a variety of sources, including reports by state-run exchanges. At the close of open enrollment, Gaba's estimates ended up being extremely close to what the administration ended up reporting.
Last month, the news site ProPublica reported that nearly 1 million transactions had occurred on HealthCare.gov since the close of open enrollment.
ProPublica's report, which was based on a Freedom of Information Act document request to HHS, noted that a transaction could include not only new enrollments, but also changes in plans by people who had a so-called qualifying life event. Still, the volume of transactions suggests there could be a significant increase in the total number of sign-ups.
Gaba argued that HHS should be releasing official numbers during the special enrollment period for several reasons.
"For one thing ... the numbers are still going up," he said. Gaba added that Obamacare is such a big issue that the public deserves to know how the program is doing, without having to wait until open enrollment begins.
"The Democrats lost the House of Representatives over this ... it has certainly sucked the oxygen out of Washington for the better part of the past four years," Gaba said. "It's important to give updates on a fairly regular basis."
He noted that the exchange run by the state of Minnesota "is almost doing daily updates. It's like an odometer."
And Oregon's exchange updates its enrollment weekly.
"I wouldn't think it would be terribly difficult" for HealthCare.gov to give such regular updates, said Gaba, noting HHS' monthly Medicaid enrollment reports.
Gaba's estimates of the current enrollments reflect only sign-ups—not possible drop-offs. He acknowledged that even as a number of people sign up, some people—possibly more—will drop their plans because they can't afford them or for other reasons. But if HHS doesn't reveal its tally, then it allows Obamacare opponents to argue that the administration has something to hide.
"If you don't release the data, then the sky's the limit—they can say anything they want," he said.
Kevin Counihan, the head of Connecticut's state-run Obamacare exchange, said he's made it a practice to release what data he can about enrollment, as well as any problems the exchange had in its operation "to create and maintain credibility."
"I may be wrong in this, but when you've got something this new and this ideologically polarizing, the best way to try to get support from both sides is to share information," Counihan said. "If you create trust, you create a buffer when things go bad."
—By CNBC's Dan Mangan