In this specific case, $ is earmarked as healthcare subsidies for households whose income falls below a threshold of about $88K. By definition not available to other taxpayers though an additional cost for them unless existing Medicaid/Medicare costs for the targeted groups already are of a similar size. Seems the CBO doesn't think that is the case.

FWIW it may not appear in articles but the CBO also has observed that under the current system costs can be expected inexorably to climb no matter how many extensions or additions are made to it. Finally, even those supporting the plan agree that there has to be an acceptable payment mechanism meaning that all these things need to be clarified before it can be expected to proceed.