5 Things The Obamacare Enrollment Numbers Won't Tell You

So is Obamacare a success? Has President Barack Obama 's signature health reform law revolutionized our broken health care system?

More than 7 million people used the Affordable Care Act's health insurance exchanges to buy private coverage through Monday, the end of the first sign-up period. Certainly the Obama administration is touting this as a huge victory .

"In these first six months, we've taken a big step forward," Obama said in the White House Rose Garden Tuesday. "The Affordable Care Act hasn't completely fixed our long-broken health care system, but this law has made our health care system a lot better."

Yet, there's still much we don't know about what the law has accomplished. Until we have answers to these five questions, it's still early to assess the full impact of Obamacare.

1. How many people really signed up for health insurance?

The 7.1 million figure the White House cited may be too low. The raw number doesn't include all of the most recent updates from 14 states and the District of Columbia, which have their own websites and saw a flurry of activity leading up to the open enrollment deadline. Nor does it include the applications still pending at the exchanges . Also missing: those who will sign up throughout the year when they become eligible because of a major life change, like marriage or moving to another state.

People who bought Obamacare-compliant insurance directly from a carrier aren't counted either .

Confusingly, the 7 million number may also be too high: We don't know how many of those people took the crucial final step and actually paid their first month's insurance premium to lock in coverage. Based on anecdotal reports from individual insurance companies, Health and Human Services Secretary Kathleen Sebelius said 80 percent to 90 percent of consumers thus far had paid up. There also will surely be people who let their policies lapse during the rest of the year.

2. How many uninsured people gained coverage?

It's logical to assume that the Affordable Care Act reduced the ranks of the uninsured. There's a legal mandate to most people get covered or face tax penalties , and the law expands Medicaid and offers generous subsidies to low-income households. But logic isn't the same as data, and the Census survey many consider the gold standard won't even come out until September 2015.

Although the federal government can't or won't say how many enrollees from HealthCare.gov and state exchanges used to be uninsured, some states are reporting those figures. In Kentucky, 270,000 of the 370,000 people who enrolled via Kynect , the state's exchange, were uninsured -- meaning 43 percent of the Kentuckians without coverage are now enrolled. Likewise, more 70 percent of the 865,000 enrollees on New York State of Health previously were uninsured.

And an unknown number of uninsured people bought private insurance outside the exchanges. From Jan. 1 to mid-March, for example, 51 percent of those buying unsubsidized coverage via online broker eHealth reported they were uninsured. In addition, as many as 3 million young adults are now covered because of the 2010 Obamacare rule letting them remain on their parents' plans until they turn 26, according to the Department of Health and Human Services.

There are signs that the impact is real. According to unpublished survey data from the Rand Corp. obtained by the Los Angeles Times, the rate of uninsured working adults fell from 20.9 percent last fall to 16.6 percent on March 22 , which the newspaper calculates as 9.5 million people gaining coverage via Medicaid and private insurance. Gallup also has reported a decline in the uninsured rate.

There were 48 million uninsured people in America in 2012 , according to the most recent Census report. The Congressional Budget Office projects the share of legal U.S. residents without health coverage will decline from 14 percent this year to 8 percent by 2024 .

But even these survey data are open to some degree of doubt. People transition on and off insurance for a variety of reasons that predate Obamacare, like getting or losing a job and its health benefits, so it's difficult to tease what's happening because of the law.

And despite persistent claims from Republican Obamacare critics , the several million people whose policies got canceled last year because they didn't meet the law's standards aren't now uninsured. Nearly all replaced that coverage with other plans, according to the Rand Corp.

3. Did enough healthy, young people get private insurance to balance out the costs of sicker people?

As of March 1, about one-quarter of nationwide private insurance enrollees were between the ages of 18 and 34, according to the Department of Health and Human Services. This matters because if only those who are heavy users of health care get covered, their medical bills will drive up future premiums. The White House originally hoped that 40 percent of those who bought the insurance would be young people , using age as an imperfect proxy for health.

The final share may or may not tick up much higher than 25 percent, but several health insurance companies recently have said their new customers were trending younger near the end of the enrollment period. EHealth reported the share of customers aged 18-34 rose from 39 percent during the first half to 45 percent during the second half.

And the impact on next year's premiums will be mitigated by Affordable Care Act funding mechanisms designed to limit the losses for insurers that attract a larger-than-normal share of sick customers.

4. How many people enrolled in Medicaid coverage?

This one should be easy to answer, but it isn't.

According to the March HHS report, 4.4 million people were deemed eligible for Medicaid or the Children's Health Insurance Program via the health insurance exchanges, including individuals who qualified because the law expanded Medicaid and those who were entitled under the old rules but weren't signed up. That figure doesn't count anyone who signed up for the programs directly through a state agency.

A February report from the Centers for Medicare and Medicaid Services revealing that state agencies deemed 8.9 million people eligible for these programs also is problematic. That figure includes a mix of people gaining access because of Obamacare, people who previously were eligible but not enrolled and people who are simply renewing their existing benefits.

Finally, Medicaid and CHIP enrollment are open year-round, so more people will sign up while others drop out over the remainder of 2014. Twenty-four states haven't adopted Obamacare's Medicaid expansion , however, which will suppress enrollment.

5. How much more is health insurance going to cost next year?

Health insurance companies like WellPoint already are making noises about "double digit" premium hikes for 2015. That reflects their concern that the new customers they gained via the exchanges are sicker than the customers they had last year, since the law now requires them to accept anyone regardless of pre-existing conditions.

There's virtually no doubt that health insurance rates will rise on average next year, because they always do. The questions are: How much will they rise, for whom and where?

The overall enrollment figures and the proportion of healthy and sick aren't what matter here. Under the Affordable Care Act, every state is its own health insurance risk pool , and sometimes it goes down to the county and local levels.

That means insurance companies will base their rates on the medical expenses they incur in each geographic location, not nationwide. The proportion of private insurance exchange customers under 35 years old varies a lot from state to state, as does the health of those populations. So consumers in some regions may get hit with big rate hikes next year, while consumers in others may see much smaller increases, or even decreases.