Three years ago, on the eve of Obamacare’s implementation, the Congressional Budget Office (CBO) projected that President Obama's centerpiece legislation would result in an average of 201 million people having private health insurance in any given month of 2016. Now that 2016 is here, the CBO says that just 177 million people, on average, will have private health insurance in any given month of this year—a shortfall of 24 million people.

Indeed, based on the CBO's own numbers, it seems possible that Obamacare has actually reduced the number of people with private health insurance. In 2013, the CBO projected that, without Obamacare, 186 million people would be covered by private health insurance in 2016—160 million on employer-based plans, 26 million on individually purchased plans. The CBO now says that, with Obamacare, 177 million people will be covered by private health insurance in 2016—155 million on employer-based plans, 12 million on plans bought through Obamacare's government-run exchanges, and 9 million on other individually purchased plans (plus a rounding error of 1 million).

In other words, it would appear that a net 9 million people have lost their private health plans, thanks to Obamacare—with a net 5 million people having lost employer-based plans and a net 4 million people having lost individually purchased plans.

None of this is to say that fewer people have "coverage" under Obamacare—it's just not private coverage. In 2013, the CBO projected that 34 million people would be on Medicaid or CHIP (the Children's Health Insurance Program) in 2016. The CBO now says that 68 million people will be on Medicaid or CHIP in 2016—double its earlier estimate. It turns out that Obamacare is pretty much a giant Medicaid expansion.

To be clear, the CBO—which has very generously labeled Obamacare's direct subsidies to insurance companies as "tax credits," even though sending money to insurers doesn't lower anyone's taxes—isn't openly declaring that Obamacare has reduced the number of people with private health insurance or that it has doubled the number of people on Medicaid or CHIP. Rather, the CBO maintains that Obamacare has actually increased the number of people with private health insurance by 9 million and has increased the number of people on Medicaid or CHIP by (just) 13 million. But it would seem that the only reason the CBO can make these claims is that it has moved the goalposts.

That is, the CBO has significantly altered its estimates for what 2016 would have looked like if Obamacare had never been passed. In 2013, the CBO projected that, in the absence of Obamacare, 186 million people would have had private health insurance in 2016, and 34 million people would have been on Medicaid or CHIP. The CBO now maintains that, in the absence of Obamacare, only 168 million people would have had private health insurance in 2016 (a reduction of 18 million people from its 2013 projection), while 55 million people would have been on Medicaid or CHIP (an increase of 21 million people from its 2013 projection). Somehow the hypothetical non-Obamacare world has changed a lot in the past three years. (The CBO doesn't explain how this could have happened.)

Even the CBO's revised figures for a non-Obamacare world, however, can't gloss over the fact that Obamacare has failed to hit its target for private health insurance by 24 million people. To see that, one must simply compare Obamacare's new tally of 177 million to its 2013 target of 201 million.

The CBO doesn't release retroactive scoring of Obamacare. Try finding, for example, tallies from the federal government (whether from the CBO or otherwise) on what Obamacare has actually cost so far. Rather, the CBO is like a handicapper who predicts the results of horseraces, but then never bothers to publish the races' actual results.

Now that it's clear enough, however, that Obamacare is basically an expensive Medicaid expansion coupled with 2,400 pages of liberty-sapping mandates, it's time for a winning Obamacare alternative to emerge, one along the lines of what Ed Gillespie almost rode to victory in the Virginia Senate race. Such an alternative should address the longstanding inequity in the tax code—between employer-based and individually purchased insurance—while adhering to four basic notions:

1. It shouldn't touch the tax treatment of the typical American's employer-based plan.

2. It should close the tax loophole on the employer side—which says that the more you spend (on insurance), the more you save (in taxes)—by capping the tax exclusion at $20,000 for a family plan (while letting anyone with a more expensive plan still get the full tax break on that first $20,000).

3. It should offer a simple tax break for individually purchased insurance that isn't income-tested and thus doesn't pick winners and losers (in marked contrast with Obamacare, which is all about picking winners and losers.)

4. It shouldn't provide direct subsidies to insurance companies like Obamacare does. (The federal government provides a tax break for mortgage interest paid—it doesn't directly pay a portion of people's mortgage bills. Likewise, it shouldn't directly pay people's health insurance bills as if it were some kind of "single payer.")

In addition, anyone crafting an Obamacare alternative should keep this important point in mind and express it publicly: Far from being the gospel truth, the CBO's scoring is more like a wild guess that will never be checked against future reality.

Update: The CBO is apparently doing two things differently in its current projections than it did in 2013: First, it now breaks out 15 million people that it apparently used to include in its "nongroup and other" category and instead lists them as being on Medicare (through Social Security Disability Insurance) or "other coverage" (such as student or foreign coverage). Second, it now lists people with more than one kind of insurance (there are apparently 14 million such people) in more than one place (e.g., someone on both employer-based insurance and Medicaid is now listed in both categories), whereas it apparently used to assign people to just one category, based on their "primary source of coverage"—a practice that resulted in the number of people with various types of insurance, plus the number of uninsured, adding up to the total population. (This new practice yields a number—for people on various types of insurance plus those who are uninsured—that exceeds the total population. It exceeds it by 14 million for 2016.) The first of these changes likely accounts for about five-eighths of the apparent shortfall in the CBO's projections for the number of people on private insurance.

The second change affects the CBO's underestimation of how many people would be on Medicaid under Obamacare. Even if we assume that all 14 million of those who are now double-counted are listed as being on Medicaid (or CHIP) but are primarily on another type of insurance, and we thus remove them from the Medicaid category (to reflect the way the CBO categorized things in 2013), that would still leave 54 million people on Medicaid (the CBO's current projection of 68 million minus 14 million), versus the CBO's projection in 2013 that, in 2016, there would be 45 million people on Medicaid under Obamacare and 34 million people on Medicaid in the absence of Obamacare. That's a difference of 9 million people on Medicaid this year versus the CBO's 2013 projection for 2016, and a difference of 20 million people on Medicaid this year versus the CBO's 2013 projection for what 2016 would have looked like without Obamacare.

Jeffrey H. Anderson, the author of an "An Alternative to Obamacare," is a Hudson Institute senior fellow.