In its latest report on the law, the Congressional Budget Office said it is no longer possible to assess the overall fiscal impact of the law. That conclusion came as a surprise to some fiscal experts in Washington and is drawing concern. And without a clear picture of the law’s overall financing, it could make it politically easier to continue delaying pieces of it, including revenue raisers, because any resulting cost increases might be hidden.

Charles Blahous, a senior research fellow at George Mason University’s free market-oriented Mercatus Center, calls the CBO’s inability to estimate the net effect of the law “a real problem.”

“The ACA’s financing provisions were assumed to be effective so as to get a favorable score out of CBO upon enactment, but no one is keeping track of whether they’re being enforced,” says Blahous, a public trustee for Social Security and Medicare. “We receive occasional updates on the gross costs of the law, but none on whether the previously projected savings provisions are producing what was originally projected.”