Frequently Asked Questions (FAQs)

What is CBO’s estimate of the deficit for 2018? What was the budget deficit for 2017?

CBO’s latest estimate (reported in June 2017) is that, if the laws governing taxes and spending generally remain unchanged in fiscal year 2018 (which ends on September 30), the deficit for the year will total $563 billion, equal to 2.8 percent of gross domestic product (GDP). The federal government ran a budget deficit of $666 billion in fiscal year 2017, equal to 3.5 percent of GDP.

Our Budget page provides quick links to our 10-year and long-term budget projections.

Where can I find CBO’s latest budget and economic projections?

CBO issues 10-year budget projections (usually three times a year), 10-year economic forecasts (usually twice a year), reports on spending and revenues in the current fiscal year (monthly), and long-term budget projections (once a year).

10-Year Budget Projections 10-Year Economic Projections Long-Term Budget Projections
Monthly Budget Reviews Historical Budget Data

Visit our Budget, Economy, Outlook for the Budget and Economy, and Taxes pages for more information.

What is a cost estimate? When does CBO prepare cost estimates for legislation? How can I get a cost estimate?

A cost estimate states the likely effects of proposed legislation on the federal budget—compared with what future spending and revenues would be under current law.

CBO is required by law to produce a formal cost estimate for nearly every bill that is approved by a full committee of either the House or the Senate; the only exceptions are appropriation bills, which do not receive formal written cost estimates but whose budgetary effects CBO estimates for the Appropriations Committees. CBO also produces formal cost estimates at other stages of the legislative process if requested to do so by a relevant committee or by the Congressional leadership. Moreover, CBO produces informal cost estimates for a much larger number of legislative proposals—including some that Congressional committees consider during the process of developing legislation, and some that receive consideration at other stages in the legislative process.

For requests for cost estimates from individual Members offices, when time permits, CBO tries to provide informal feedback on possible direct spending effects, usually by phone or email. If you’re seeking a cost estimate from CBO, simply submit your request, with any draft language attached or the bill number referenced, by email to That address is monitored by our Budget Analysis Division and they will route your request to the proper analyst. If we can’t work on your estimate right away, CBO will try to give you a sense of whether and when the estimate can be prepared.

Our Cost Estimates page provides all of our estimates in chronological order, with the most recent estimates shown first. The estimates are searchable by the number, title, committee, and program area of bills. View our Frequently Asked Questions About CBO Cost Estimates to learn more about CBO’s estimates.

How does CBO account for new information in its estimates?

CBO typically updates its baseline budget projections at specific times each year to reflect legislative action, economic changes, and other developments. Generally, the budgetary impact of legislation being considered in the House or Senate is measured relative to the baseline produced in the spring.

During the course of a year, however, events sometimes occur that are different from those anticipated in developing the baseline projections. In such cases, CBO follows long-standing procedures governing when and how to take into account such developments, which sometimes include the enactment of legislation, actions by the courts, or decisions by executive branch agencies.

If new information indicates that an action or event that would affect CBO’s baseline has happened or definitely will happen (such as a Supreme Court decision, or an agency issuing a final rule or making an official announcement that clearly indicates an intended action by the Administration), CBO incorporates that information in its next regular baseline update. In addition, CBO immediately takes that information into account in assessing what will happen under current law when it analyzes the effects of legislation being considered by the Congress, even if the agency has not published new baseline projections.

How do I find CBO’s major reports?

Looking for current and previous installments of CBO’s Budget and Economic Outlook, Long-Term Budget Outlook, or Analysis of the President’s Budget?

CBO’s page on major recurring reports has links to those and other key reports going back to 2000.

How do I find budget options and reports with policy options?

CBO produces numerous reports with specific options and broad approaches for changing federal tax and spending policies.

CBO periodically issues a volume of policy options—often referred to as “Budget Options”—covering a broad range of issues as well as separate reports that include policy options in particular areas.

Find budget options from recent volumes as well as some options that appeared in separate reports on CBO’s digital budget options page. You can sort by major budget category (mandatory spending, discretionary spending, or revenues), budget function (such as national defense, transportation, or income security), and by topic (such as housing, Medicare, or business and finance).

A related page—Reports with Policy Options—organizes CBO’s analytic reports that include policy options by broad issue area.

In addition to the budget options volume and various analytic reports, another report—Choices for Deficit Reduction: An Update—frames the choices that policymakers need to make, summarizes policy alternatives, and provides criteria that might be used to evaluate policy changes. (This is a companion report to CBO’s 2013 budget options volume, but the information presented is still largely relevant.)

Note: The agency’s most recent estimate of the budgetary effects of an option might differ from previous estimates or future estimates for various reasons. One reason is that the effects of policy options are measured relative to CBO’s latest projections of budget outcomes under current law; when CBO’s “baseline” projections change, the options’ estimated budgetary effects can change as well. Another reason is that CBO regularly incorporates new analysis—by the agency or others—in order to improve its estimates. A third reason that estimates can change over time is that the details of largely similar options may differ in ways that give rise to differences in their budgetary effects.

What are CBO’s latest projections for Medicare, Medicaid, and other health care programs?

For CBO’s latest projections of spending for major health care programs, see Table 2 of An Update to the Budget and Economic Outlook: 2017 to 2027 (June 2017).

How many people under age 65 are projected to have health insurance?

The most recent estimates of these amounts by CBO and the staff of the Joint Committee on Taxation (JCT) were included in the September 2017 report Federal Subsidies for Health Insurance Coverage for People Under Age 65: 2017 to 2027.

At that time, CBO and JCT projected that an average of about 244 million noninstitutionalized U.S. civilians under age 65 would have health insurance in any given month in 2017. Almost two-thirds of them were expected to obtain coverage through an employer, and about a quarter were projected to be enrolled in Medicaid or the Children’s Health Insurance Program (CHIP). A smaller number were expected to have nongroup coverage, coverage provided by Medicare, or coverage obtained from other sources. On average, about 28 million people—10 percent of all noninstitutionalized civilians younger than 65—were projected to be uninsured in 2017. Between 2017 and 2018, the number of uninsured people was projected to rise by 2 million, mainly because premiums in the nongroup market were expected to rise.

From 2018 through 2027, the number of people with coverage was expected to grow from 242 million to 247 million, mostly because of increased enrollment in Medicaid. But the number of uninsured people was also expected to grow, from 30 million to 31 million, keeping the uninsured share of the under-65 population at 11 percent throughout that period.

How large are the projected federal subsidies, taxes, and penalties associated with health insurance coverage for people under age 65?

The most recent estimates of these amounts by CBO and the staff of the Joint Committee on Taxation (JCT) were included in the September 2017 report Federal Subsidies for Health Insurance Coverage for People Under Age 65: 2017 to 2027.

At that time, CBO and JCT estimated that in 2017 the federal subsidies, taxes, and penalties associated with health insurance coverage would result in a net subsidy from the federal government of $705 billion, or 3.7 percent of gross domestic product (GDP). That amount was projected to rise at an average annual rate of 5.0 percent between 2017 and 2027, reaching $1.2 trillion (or 4.1 percent of GDP) in 2027. For the entire 2018–2027 period, the projected net subsidy was $9.2 trillion. Two types of costs account for most of that amount:

  • Federal spending for people under age 65 with full Medicaid and CHIP benefits (excluding those who reside in a nursing home or other institution) was projected to amount to $4.0 trillion. That amount includes $1.0 trillion in subsidies for people whom the ACA made eligible for Medicaid.
  • Federal subsidies for work-related coverage for people under age 65, which stem mainly from the exclusion of most premiums for such coverage from income and payroll taxes, were projected to be $3.9 trillion.

Other subsidy costs were smaller:

  • Medicare benefits for noninstitutionalized beneficiaries under age 65 (net of their premium payments and other offsetting receipts) were projected to amount to $1.0 trillion. Such spending is primarily for people who are disabled.
  • Subsidies for coverage obtained through the marketplaces established under the Affordable Care Act or through the Basic Health Program were estimated to total $0.8 trillion.

The costs of those subsidies were projected to be offset to a small extent, $0.5 trillion, by taxes and penalties collected from health insurance providers, uninsured people, and employers.

What are CBO’s latest estimates of the cost of the insurance coverage provisions of the ACA and how have those estimates changed?

The most recent estimates of these amounts by CBO and the staff of the Joint Committee on Taxation (JCT) were prepared as part of the March 2016 baseline projections.

The effects of the health insurance coverage provisions of the ACA are incorporated into estimates of overall health insurance coverage and are a subset of the estimates of the net federal subsidies associated with such coverage that are discussed above. To separate the effects of the ACA’s coverage provisions from those broader estimates, CBO and JCT compared their 2016 projections with estimates of what would have occurred if the ACA had never been enacted. For the 2017–2026 period, the projected net cost of those provisions was $1.4 trillion. Those estimates were included in CBO’s March 2016 report Federal Subsidies for Health Insurance Coverage for People Under Age 65: 2016 to 2026 and address only the insurance coverage provisions of the ACA, which do not generate all of the law’s budgetary effects. Many other provisions—such as various tax provisions that increase revenues and reductions in Medicare payments to hospitals, to other providers of care, and to private insurance plans delivering Medicare’s benefits—are, on net, expected to reduce budget deficits.

For the 2016–2025 period, CBO and JCT’s March 2016 projection of the net cost of the ACA’s insurance coverage provisions was $136 billion higher than their March 2015 estimate (from the last detailed projections that the agencies published). The largest difference from the March 2015 projection stemmed from an increase in projected spending for Medicaid because more people whom the ACA made eligible for Medicaid were expected to enroll than were anticipated when the 2015 projection was made. Compared with the projection made by CBO and JCT in March 2010, just before the ACA was enacted, the March 2016 estimate of the net cost of the insurance coverage provisions over the 2016–2019 period (the final years of the 10-year budget window used in the original report) was lower by $157 billion, or 25 percent.

How many people, according to CBO’s estimates, will have insurance coverage through the health insurance marketplaces?

Under the ACA, individuals and families can purchase health insurance through the marketplaces operated by the federal government, state governments, or partnerships between the federal and state governments; those meeting certain criteria may receive federal subsidies for that coverage. In September 2017, CBO and the staff of the Joint Committee on Taxation (JCT) estimated that, in any given month, an average of about 10 million people will be covered by insurance purchased through the marketplaces during 2017. The agencies estimate that 8 million of those people will receive subsidies to purchase their coverage.

CBO and JCT estimate that average enrollment in any given month during the year will be lower than the number of people who selected a plan by the end of the open-enrollment period and lower than the total number of people who will have coverage at some point during the year. Some people are covered for only part of the year, and enrollment varies over the course of a year because people who experience a qualifying life event (such as a change in income or family size or the loss of employment-based insurance) are allowed to purchase coverage later in the year and because some people stop paying the premiums or leave their marketplace-based coverage as they become eligible for insurance through other sources.

CBO and JCT expect average enrollment to continue to increase to 11 million people in 2018 and to 12 million in 2019. About 10 million people are expected to receive subsidies for purchasing that insurance each year after 2018.

What is CBO’s current estimate of the budgetary effects of the Affordable Care Act (ACA)?

Although CBO’s baseline projections incorporate the budgetary effects of the Affordable Care Act’s (ACA’s) insurance coverage provisions over the coming decade, CBO cannot readily provide a new estimate that separately identifiers all of the budgetary effects of the ACA. The reasons for that are explained in a June 2014 blog post, which highlights the following points:

  • The incremental budgetary effects of many provisions of the ACA are embedded in CBO’s baseline projections for preexisting programs and tax revenues, and they cannot be separately identified using the agencies’ normal estimating procedures—which are generally based on data that reflect all of the provisions of current law, including the ACA.
  • A retrospective analysis of the effects of a current law is very different from a cost estimate for proposed legislation, particularly because it requires formulation of a counterfactual benchmark representing what would have happened if the law had not been enacted—a challenging undertaking that is beyond the scope of CBO’s usual analyses.
  • Therefore, CBO and the staff of the Joint Committee on Taxation (JCT) cannot readily provide a retrospective analysis of the ACA that is analogous to the cost estimate provided by the agencies when the legislation was considered in 2010. That problem is not unique to the ACA but is common to most legislation that affects preexisting federal programs.

Visit our Affordable Care Act page for CBO’s work on this topic, and visit our Health Care page for all of CBO’s work related to health care.

What is CBO’s latest estimate of the budgetary effects of repealing the ACA?

Consistent with their statutory responsibilities, CBO and the staff of the Joint Committee on Taxation (JCT) can continue to estimate the effects of prospective legislative actions, such as proposals to modify provisions of the Affordable Care Act (ACA) or to repeal the law entirely. Because of the complexities involved in implementing a repeal of the ACA, the budgetary effects of repealing the act would not simply be the opposite of the budgetary effects of the ACA itself.

CBO’s most recent estimate of the budgetary impact of repealing the entire ACA was published in June 2015. In that report, CBO and JCT analyzed the main budgetary and economic effects of repealing that law and concluded that doing so would probably increase federal deficits over the next decade, whether or not the effects on the overall economy are taken into account. Those macroeconomic “feedback” effects would reduce deficits, but would not offset the increases in deficits stemming from the other consequences of repealing the ACA. Since then, CBO has revised some components of its estimates and legislation has been enacted that will also affect them.

More recently, CBO and JCT have analyzed legislation that would have repealed some, but not all, of the ACA’s provisions. For example, several iterations of H.R. 1628, the Better Care Reconciliation Act of 2017, were projected to reduce deficits over 10 years. However, that bill would not have repealed all of the ACA’s provisions; in particular, the ACA’s reductions in Medicare payments would not have been repealed. CBO and JCT have also estimated the budgetary effects of just repealing the individual health insurance mandate, projecting that, by itself, such a change would reduce federal deficits by about $338 billion over the 2018–2027 period and increase the number of uninsured people by 4 million in 2019 and 13 million in 2027.

In their June 2015 estimate, CBO and JCT projected that repealing the entire ACA would have several major effects, relative to the projections under current law, as discussed below.

Estimated Effect on Deficits: Including the budgetary effects of macroeconomic feedback, repealing the ACA would increase federal budget deficits by $137 billion over the 2016–2025 period. That estimate takes into account the proposal’s impact on federal revenues and direct spending, incorporating the net effects of two components:

  • Excluding the effects of macroeconomic feedback—as has been done for previous estimates related to the ACA (and most other CBO cost estimates)—CBO and JCT estimated that federal deficits would increase by $353 billion over the 2016–2025 period if the ACA was repealed.
  • Repeal of the ACA would raise economic output, mainly by boosting the supply of labor; the resulting increase in GDP is projected to average about 0.7 percent over the 2021–2025 period. Alone, those effects would reduce federal deficits by $216 billion over the 2016–2025 period, CBO and JCT estimated, mostly because of increased federal revenues.

Uncertainty Surrounding the Estimates: For many reasons, the budgetary and economic effects of repealing the ACA could differ substantially, and in either direction, from the central estimates described above. The uncertainty is sufficiently great that repealing the ACA could reduce deficits over the 2016–2025 period—or could increase deficits by a substantially larger margin than the agencies have estimated. However, CBO and JCT’s best estimate was that repealing the ACA would increase federal budget deficits by $137 billion over that 10-year period.

Impact on the Economy and the Budget Beyond 2025: Repealing the ACA would cause federal budget deficits to increase by growing amounts after 2025, whether or not the budgetary effects of macroeconomic feedback are included. That would occur because the net savings attributable to a repeal of the law’s insurance coverage provisions would grow more slowly than would the estimated costs of repealing the ACA’s other provisions—in particular, those provisions that reduce updates to Medicare’s payments. The estimated effects on deficits of repealing the ACA are so large in the decade after 2025 as to make it unlikely that a repeal would reduce deficits during that period, even after considering the great uncertainties involved.

Effect on Insurance Coverage: Repealing the ACA also would affect the number of people with health insurance and their sources of coverage. In June 2015, CBO and JCT estimated that the number of nonelderly people who are uninsured would increase by about 19 million in 2016; by 22 million or 23 million in 2017, 2018, and 2019; and by about 24 million in all subsequent years through 2025, compared with the number who are projected to be uninsured under the ACA. In most of those years, the number of people with employment-based coverage would increase by about 8 million, and the number with coverage purchased individually or obtained through Medicaid would decrease by between 30 million and 32 million.

Visit our Affordable Care Act page for CBO’s work on this topic.

Does CBO do “dynamic scoring”?

The short answer: Yes, but only under specific circumstances.

The concurrent resolution on the budget for fiscal year 2018 and a House rule for the 115th Congress require CBO, to the greatest extent practicable, to incorporate the budgetary impact of macroeconomic effects into its 10-year cost estimates for “major” legislation that Congressional authorizing committees approve. Incorporating such macroeconomic feedback into cost estimates for legislation is often called “dynamic scoring.”

That requirement previously appeared in the concurrent resolution on the budget for fiscal year 2016. An example of how CBO implemented the requirement can be seen in a cost estimate for H.R. 3762, the Restoring Americans’ Healthcare Freedom Reconciliation Act (January 4, 2016). For a more general discussion, see a presentation and a blog post about dynamic scoring, both published in 2015.

Major legislation is defined as having either a gross budgetary effect, before incorporating macroeconomic effects, of 0.25 percent of GDP in any year over the next 10 years, or having been designated as such by the Chairman of either Budget Committee. Those macroeconomic effects might include, for example, changes in the supply of labor or in private investment. Such estimates must also include, when practicable, a qualitative assessment of the budgetary effects for the following 20 years.

Since the Congressional budget process was established in the 1970s, CBO’s cost estimates have typically not included dynamic analysis—and most still do not because the majority of bills do not meet the definition of major legislation. Furthermore, completing macroeconomic analysis of all proposed legislation would not be feasible—it would require complex modeling and a significant amount of time; most legislation analyzed by CBO would have negligible macroeconomic effects (and thus negligible feedback to the federal budget); and estimates of macroeconomic effects are highly uncertain.

In analyses other than cost estimates, CBO has produced a number of estimates of how some proposals that would significantly change federal spending and tax policies would affect the overall economy, as well as how such effects would affect the federal budget. Recent reports incorporating such analyses include the agency’s annual examination of the economic impact of the President’s budget, its annual Long-Term Budget Outlook, and several reports on the macroeconomic effects of alternative budgetary paths.

You can see these reports and other work in this area on our Dynamic Analysis web page. (Also see CBO’s Economic Effects of Fiscal Policy page for additional analyses focused primarily on economic outcomes.)

How can I learn about CBO’s products, processes, and organization?

Visit our About CBO section to learn more.

Where can I learn about CBO’s career and business opportunities?

Visit our About CBO section to learn more.

Where can I find some definitions of key terms used in your reports? For example, what’s the difference between the deficit and the debt?

CBO’ s glossary defines various economic and budgetary terms as they are used in our reports. The document is updated periodically—most recently in 2012.