There are dozens of temporary tax provisions in the Internal Revenue Code (IRC), many of which had expired at the end of 2014. Recent legislation has extended certain expiring provisions, and, in some cases, made temporary provisions permanent. The American Taxpayer Relief Act (ATRA; P.L. 112-240 ), signed into law on January 2, 2013, reduced tax policy uncertainty by permanently extending most of the tax cuts first enacted in 2001 and 2003 and permanently indexing the alternative minimum tax (AMT) for inflation. ATRA, however, did not eliminate uncertainty in the tax code. Under ATRA, a number of provisions that had been allowed to expire at the end of 2011 or 2012 were temporarily extended through 2013. Most of the provisions that expired at the end of 2013 were retroactively extended for one year, through 2014, in the Tax Increase Prevention Act of 2014 ( P.L. 113-295 ). The Consolidated Appropriations Act, 2016 ( P.L. 114-113 ), signed into law on December 18, 2015, either made permanent or temporarily extended all tax provisions that had expired at the end of 2014. Collectively, temporary tax provisions that are regularly extended by Congress rather than being allowed to expire as scheduled are often referred to as "tax extenders." Many of these "tax extender" provisions have been temporarily extended multiple times. The research tax credit, for example, was extended 16 times since being enacted in 1981, before being modified and made permanent in P.L. 114-113 . Most of the temporary tax provisions that had expired at the end of 2014 were previously extended more than once. In the 114 th Congress, much of the debate on tax extenders focused on whether expired tax provisions should be made permanent, or temporarily extended. In P.L. 114-113 , all expired tax provisions were extended, either temporarily or by being made permanent. Making a number of expired provisions permanent reduced uncertainty in the tax code, by reducing the number of temporary provisions scheduled to expire. However, as not all expired provisions were made permanent, there are still a number of tax extenders set to expire at the end of 2016. Debate in the second half of the 114 th Congress may address whether the provisions set to expire at the end of 2016 should be extended. This report provides a broad overview of the tax extenders. Additional information on specific extender provisions may be found in other CRS reports, including the following: CRS Report R43510, Selected Recently Expired Business Tax Provisions ("Tax Extenders") , by [author name scrubbed], [author name scrubbed], and [author name scrubbed]; CRS Report R43688, Selected Recently Expired Individual Tax Provisions ("Tax Extenders"): In Brief , by [author name scrubbed] and [author name scrubbed]; CRS Report R43517, Recently Expired Charitable Tax Provisions ("Tax Extenders"): In Brief , by [author name scrubbed] and [author name scrubbed]; CRS Report R43541, Recently Expired Community Assistance-Related Tax Provisions ("Tax Extenders"): In Brief , by [author name scrubbed]; and CRS Report R43449, Recently Expired Housing Related Tax Provisions ("Tax Extenders"): In Brief , by [author name scrubbed]. The Consolidated Omnibus Appropriations Act, 2016 ( P.L. 114-113 ) contained, as Division Q, the Protecting Americans from Tax Hikes Act of 2015 (PATH Act). The PATH Act either temporarily extended or made permanent all tax provisions that had expired at the end of 2014. Further, the PATH Act also made permanent the enhanced child tax credit, the enhanced American Opportunity Tax Credit, and the enhanced earned income tax credit, which were scheduled to expire in 2017. The PATH Act also included a two-year moratorium on the medical device excise tax. Division P of P.L. 114-113 also contained tax-related provisions, including changes to and a two-year moratorium on the high-cost employer-sponsored health coverage excise tax, a one-year moratorium on the annual fee on health insurance providers, extensions of tax credits for wind renewable power facilities and solar energy, and changes to the Section 199 deduction for independent oil refineries. The Tax Increase Prevention Act of 2014, passed late in the 113 th Congress, extended expiring tax provisions for one year, retroactively through 2014. Other legislation considered in the 113 th Congress proposed a two-year extension—the Expiring Provisions Improvement Reform and Efficiency (EXPIRE) Act ( S. 2260 ). Legislation was also considered that would have made certain expiring provisions permanent—see, for example, the Jobs for America Act ( H.R. 4 ) and the America Gives More Act of 2014 ( H.R. 4719 ). Tax reform legislation introduced in the 113 th Congress, the Tax Reform Act of 2014 ( H.R. 1 ), proposed to make permanent certain provisions that are currently part of the tax extenders, including the research and experimentation (R&D) tax credit and increased expensing allowances for certain businesses allowed under Internal Revenue Code (IRC) Section 179. In the 114 th Congress, the House had passed legislation that would permanently extend certain expired provisions (America's Small Business Tax Relief Act of 2015 [ H.R. 636 ], State and Local Sales Tax Deduction Fairness Act of 2015 [ H.R. 622 ], America Gives More Act of 2015 [ H.R. 644 ], and American Research and Competitiveness Act of 2015 [ H.R. 880 ]). The Tax Relief Extension Act of 2015 ( S. 1946 ), as reported by the Senate Committee on Finance, would have extended the temporary provisions that expired at the end of 2014 for two years, making the provisions available for the 2015 and 2016 tax year. S. 1946 would have extended all temporary tax provisions that expired at the end of 2014, as well as one provision that expired at the end of 2013. The tax code presently contains dozens of temporary tax provisions. In the past, legislation to extend some set of these expiring provisions has been referred to by some as the "tax extender" package. While there is no formal definition of a "tax extender," the term has regularly been used to refer to the package of expiring tax provisions temporarily extended by Congress. Oftentimes, these expiring provisions are temporarily extended for a short period of time (e.g., one or two years). Over time, as new temporary provisions have been routinely extended and hence added to this package, the number of provisions that might be considered "tax extenders" has grown. There are various reasons Congress may choose to enact temporary (as opposed to permanent) tax provisions. Enacting provisions on a temporary basis, in theory, would provide Congress with an opportunity to evaluate the effectiveness of specific provisions before providing further extension. Temporary tax provisions may also be used to provide relief during times of economic weakness or following a natural disaster. Congress may also choose to enact temporary provisions for budgetary reasons. Examining the reason why a certain provision is temporary rather than permanent may be part of evaluating whether a provision should be extended. There are several reasons why Congress may choose to enact tax provisions on a temporary basis. Enacting provisions on a temporary basis may provide an opportunity to evaluate effectiveness before expiration or extension. However, this rationale for enacting temporary tax provisions is undermined if expiring provisions are regularly extended without systematic review, as is the case in practice. In 2012 testimony before the Senate Committee on Finance, Dr. Rosanne Altshuler noted that an expiration date can be seen as a mechanism to force policymakers to consider the costs and benefits of the special tax treatment and possible changes to increase the effectiveness of the policy. This reasoning is compelling in theory, but has been an absolute failure in practice as no real systematic review ever occurs. Instead of subjecting each provision to careful analysis of whether its benefits outweigh its costs, the extenders are traditionally considered and passed in their entirety as a package of unrelated temporary tax benefits. While most expiring tax provisions have been extended in recent years, there have been some exceptions. For example, tax incentives for alcohol fuels (e.g., ethanol), which can be traced back to policies first enacted in 1978, were not extended beyond 2011. The Government Accountability Office (GAO) had previously found that with the renewable fuel standard (RFS) mandate, tax credits for ethanol were duplicative and did not increase consumption. Congress may choose not to extend certain provisions if an evaluation determines that the benefits provided by the provision do not exceed the cost (in terms of foregone tax revenue). Tax policy may also be used to address temporary circumstances in the form of economic stimulus or disaster relief. Economic stimulus measures might include bonus depreciation or generous expensing allowances. Disaster relief policies might include enhanced casualty loss deductions or additional net operating loss carrybacks. Other recent examples of temporary provisions that have been enacted to address special economic circumstances include the exclusion of mortgage forgiveness from taxable income during the recent housing crisis, the payroll tax cut, and the grants in lieu of tax credits to compensate for weak tax-equity markets during the economic downturn (the Section 1603 grants). It has been argued that provisions that were enacted to address a temporary situation should be allowed to expire once the situation is resolved. Congress may also choose to enact tax policies on a temporary basis for budgetary reasons. If policymakers decide that legislation that reduces revenues must be paid for, it is easier to find resources to offset short-term extensions rather than long-term or permanent extensions. Additionally, by definition the Congressional Budget Office (CBO) assumes under the current law baseline that temporary tax cuts expire as scheduled. Thus, the current law baseline does not assume that temporary tax provisions are regularly extended. Hence, if temporary expiring tax provisions are routinely extended in practice, the CBO current law baseline would tend to overstate projected revenues, making the long-term revenue outlook stronger. In other words, by making tax provisions temporary rather than permanent, these provisions have a smaller effect on the long-term fiscal outlook. Temporary tax benefits are a form of federal subsidy that treats eligible activities favorably compared to others, and channels economic resources into qualified uses. Extenders influence how economic actors behave and how the economy's resources are employed. Like all tax benefits, extenders can be evaluated by looking at the impact on economic efficiency, equity, and simplicity. Temporary tax provisions may be efficient and effective in accomplishing their intended purpose, though not equitable. Alternatively, an extender may be equitable but not efficient. Policymakers may have to choose the economic objectives that matter most. Extenders often provide subsidies to encourage more of an activity than would otherwise be undertaken. According to economic theory, in most cases an economy best satisfies the wants and needs of its participants if markets allocate resources free of distortions from taxes and other factors. Market failures, however, may occur in some instances, and economic efficiency may actually be improved by tax distortions. Thus, the ability of extenders to improve economic welfare depends in part on whether or not the extender is remedying a market failure. According to theory, a tax extender reduces economic efficiency if it is not addressing a specific market failure. An extender is also considered relatively effective if it stimulates the desired activity better than a direct subsidy. Direct spending programs, however, can often be more successful at targeting resources than indirect subsidies made through the tax system such as tax extenders. A tax is considered to be fair when it contributes to a socially desirable distribution of the tax burden. Tax benefits such as the extenders can result in individuals with similar incomes and expenses paying differing amounts of tax, depending on whether they engage in tax-subsidized activities. This differential treatment is a deviation from the standard of horizontal equity, which requires that people in equal positions should be treated equally. Another component of fairness in taxation is vertical equity, which requires that tax burdens be distributed fairly among people with different abilities to pay. Most extenders are considered inequitable because they benefit those who have a greater ability to pay taxes. Those individuals with relatively less income and thus a reduced ability to pay taxes may not have the same opportunity to benefit from extenders as those with higher income. The disproportionate benefit of tax expenditures to individuals with higher incomes reduces the progressivity of the tax system, which is often viewed as a reduction in equity. An example of the effect a tax benefit can have on vertical equity is illustrated by two teachers who have both incurred $250 in classroom-related expenses and are eligible to claim the above-the-line deduction for expenses. Yet the tax benefit to the two differs if they are in different tax brackets. A teacher with lower income, who may be in the 15% income tax bracket, receives a deduction with a value of $37.50, while another teacher, in the 33% bracket, receives a deduction value of $82.50. Thus, the higher-income taxpayer, with presumably greater ability to pay taxes, receives a greater benefit than the lower-income taxpayer. Extenders contribute to the complexity of the tax code and raise the cost of administering the tax system. Those costs, which can be difficult to isolate and measure, are rarely included in the cost-benefit analysis of temporary tax provisions. In addition to making the tax code more difficult for the government to administer, complexity also increases costs imposed on individual taxpayers. With complex incentives, individuals devote more time to tax preparation and are more likely to hire paid preparers. Dozens of temporary tax provisions had expired at the end of 2014, all of which were extended in P.L. 114-113 (see Table 1 ). Most of these provisions have been extended as part of previous "tax extender" legislation. For the purposes of this report, provisions that expired in 2014 have been classified as belonging to one of four categories: individual, business, charitable, or energy. The following sections provide additional details. Table 1 also includes information on the cost of the extension in P.L. 114-113 , as enacted. All six of the individual tax extender provisions that expired at the end of 2014 had previously been extended as part of tax extenders legislation. The longest-standing individual extender provision is the above-the-line deduction for classroom expenses incurred by school teachers. This provision was first enacted on a temporary basis in 2002 and has regularly been included in tax extender packages. The above-the-line deduction for classroom expenses was made permanent in P.L. 114-113 . Other individual provisions that have been extended more than once include the deduction for state and local sales taxes, the above-the-line deduction for tuition and related expenses, the deduction for mortgage insurance premiums, and the parity for the exclusion of employer-provided mass transit and parking benefits. The deduction for state and local sales taxes and the provision providing parity for the exclusion of employer-provided mass transit and parking benefits were also made permanent in P.L. 114-113 . All of the business provisions that expired at the end of 2014 had previously been extended at least once, most more than once. Long-standing provisions that expired at the end of 2014 include the research tax credit, the rum excise tax cover-over, the Work Opportunity Tax Credit, the Qualified Zone Academy Bond (QZAB) allocation limitation, and the active financing exception under Subpart F. The New Markets Tax Credit, first enacted in 2000 to promote investment in low-income communities, also expired at the end of 2014. Bonus depreciation and enhanced expensing allowances, which are often viewed as economic stimulus measures, also expired at the end of 2014. A number of business-related extender provisions were made permanent in P.L. 114-113 , including the research tax credit, enhanced expensing under Section 179, and the active financing exception under Subpart F. Other provisions, including the New Markets Tax Credit and bonus depreciation, were given longer-term extensions, through 2019. Table 1 provides additional information on which business tax extenders were made permanent, extended through 2019, or extended through 2016. The four charitable provisions that expired at the end of 2014 have previously been extended multiple times. All four provisions were also made permanent in P.L. 114-113 . The provision providing an enhanced deduction for noncorporate businesses donating food inventory was first enacted in response to Hurricane Katrina in 2005. The remaining charitable provisions were first enacted as part of the Pension Protection Act of 2006 ( P.L. 109-280 ). The longest-standing energy-related provision that expired at the end of 2014 is the renewable energy production tax credit (PTC). The PTC was extended for two years, through 2016, as part of P.L. 114-113 . P.L. 114-113 extended the PTC for wind through 2019, with a phase-down starting in 2017. Several of the temporary energy-related tax provisions that expired at the end of 2014 were first enacted as part of the Energy Policy Act of 2005 (EPACT05; P.L. 109-58 ). These include the credit for construction of energy efficient new homes, the deduction for energy efficient commercial buildings, and the credit for nonbusiness energy property (also known as the tax credit for energy efficiency improvements for existing homes). Certain tax incentives for alternative technology vehicles and alternative fuel vehicle refueling property were also first included in EPACT05. These provisions were all extended through 2016 in P.L. 114-113 . The alternative motor vehicle credit for qualified fuel cell vehicles also expired at the end of 2014. This provision was introduced as part of EPACT05, and was originally set to expire December 31, 2014, when first introduced. EPACT05 incentives for other alternative motor vehicles—including hybrids, alternative fuel, and advanced lean-burn technology vehicles—expired at earlier dates. The credit for two-wheeled plug-in electric vehicles expired at the end of 2013, and was not extended as part of P.L. 113-295 , but would be extended in the Tax Relief Extension Act of 2015 (S. 1946). The credit was first enacted as part of the American Recovery and Reinvestment Act (ARRA; P.L. 111-5 ) and was extended once previously by the American Taxpayer Relief Act (ATRA; P.L. 112-240 ). Both the alternative motor vehicle credit for qualified fuel cell vehicles and the credit for two-wheeled plug-in electric vehicles were extended through 2016 in P.L. 114-113 . As discussed above, Congress has regularly acted to temporarily extend expired or expiring tax provisions. In addition to temporarily extending expired provisions, P.L. 114-113 also made certain provisions permanent. As a result, the cost of the tax extenders in P.L. 114-113 was higher than the cost of other tax extenders proposals considered in the 114 th Congress that would not have included permanent extensions. In total, the extensions of tax extenders in P.L. 114-113 , is estimated to reduce federal revenues by $628.8 billion between 2016 and 2025. Of that cost, nearly one-third ($202.1 billion) is attributable to extensions of provisions that were scheduled to expire in 2017 (the reduced earnings threshold for the refundable portion of the child tax credit; the American Opportunity Tax Credit; and modifications to the earned income tax credit) and the two-year moratorium on the medical device excise tax. Thus, the cost of extending the "tax extender" provisions listed in Table 1 is an estimated $426.8 billion between 2016 and 2025. Of the total cost of the tax extenders in P.L. 114-113 , $559.5 billion, or 89% of the total cost, is associated with permanent extensions. The estimated cost of permanent extension of provisions listed in Table 1 (provisions that had expired in 2014 and were made permanent in P.L. 114-113 ) is $361.4 billion. Of the total cost of tax extenders in P.L. 114-113 , a small portion, $17.7 billion (or less than 3%) was for the two-year extension of provisions that had expired in 2014 through 2016. Before P.L. 114-113 was passed, legislation was considered in the House in the 114 th Congress that would have made permanent certain temporary tax provisions. Cost of temporary as opposed to permanent extension has, in the past, been one consideration in the debate surrounding the extension of temporary tax provisions. The Senate Finance Committee reported legislation in 2015, the Tax Relief Extension Act of 2015 ( S. 1946 ), that would retroactively extend expired tax provisions, for two years, through 2016. The JCT estimated that extending tax extenders, as proposed in S. 1946 , would have reduced revenue by $97.1 billion between 2016 and 2025. S. 1946 also included several revenue raising provisions, which brought the cost of the proposal to $96.9 billion. Neither of these figures include macroeconomic effects. With macroeconomic effects included, the cost of extending expired provisions, as proposed in S. 1946 , was $86.6 billion over the 10-year budget window. According to the JCT, extending certain expired provisions affecting businesses, particularly the provision allowing businesses to expense 50% of investments, is expected to increase economic growth in the near term. Thus, the cost estimate when macroeconomic effects are included is less than the cost estimate that does not incorporate macroeconomic effects. Since S. 1946 is projected to increase the federal debt, part of the gain in economic growth from extending expired business-related provisions would be expected to be offset by higher interest rates, which tend to slow economic growth. The net effect of JCT's macroeconomic analysis, however, was increased economic growth within the budget window, leading to a lower cost estimate for S. 1946 . The Congressional Budget Office (CBO) provides estimated costs of extending all tax provisions scheduled to expire before 2025 (see Table 2 ). The estimates below reflect information provided before the recent extensions enacted in P.L. 114-113 . CBO's estimates can be viewed as the cost of a long-term extension. According to CBO's estimates, over the 2016 to 2025 budget window, extending all expiring tax provisions would reduce revenues by $897.9 billion; extending bonus depreciation would cost $223.6 billion and extending Section 179 expensing would cost $60.8 billion; and extending expansions to the child tax credit, the earned income tax credit, and the American Opportunity Tax Credit currently scheduled to expire at the end of 2017 would cost $202.8 billion. Of the 70 tax provisions set to expire before the end of 2025 in CBO's estimates, 52 had expired at the end of 2014. Thus, most of the revenue cost associated with extending expiring provisions is for provisions that were either extended or made permanent in P.L. 114-113 . Since tax extender provisions are assumed to expire as scheduled by CBO, their extension—even if expected by policymakers—is not included in CBO's current law revenue baseline. As a result, CBO's revenue projections are higher than actual revenue levels that are likely to occur. Consequently, projected budget deficits under the current law baseline are smaller than actual deficits that are likely to occur. The cost of providing a short-term extension, as is typical in "tax extenders" legislation, is less than the cost of extending expiring provisions through the budget window, as is done by CBO for the purposes of constructing the alternative fiscal scenario baseline. The CBO scores presented here, some might argue, provide a more accurate measure of the overall or long-term budget impact of temporary tax provisions. The Joint Committee on Taxation (JCT) scores accompanying extenders legislation reflect the budget impact of the temporary extension relative to current law. If expiring provisions are temporarily extended, the 10-year revenue cost may be less than the cost in year 2015, as many of the expired provisions are tax deferrals, or timing provisions. Bonus depreciation is one example of a timing provision, where the short-term cost of extension is greater than the long-term or budget window cost. The one-year extension of bonus depreciation enacted as part of the Taxpayer Relief Act of 2014 ( P.L. 113-295 ) cost an estimated $1.2 billion over the 10-year budget window; however, the one-year revenue loss of the same provision in 2015 was $45.3 billion, with much of the cost recovered in the later years in the budget window. Bonus depreciation was extended through 2019 in P.L. 114-113 , at a cost of $11.3 billion over the 10-year budget window. The cost in 2016 is estimated to be $90.6 billion, with much of the estimated revenue cost in 2016, 2017, and 2018, recovered later in the budget window. As a timing provision, bonus depreciation shifts cost recovery forward, resulting in revenue losses in earlier years, with part of that revenue loss recovered in later years. In contrast to a temporary extension, making bonus depreciation permanent would cost $223.6 billion over the 10-year budget window (see Table 2 ). As discussed above, the tax extenders legislation that was passed in December 2015, as part of P.L. 114-113 , made permanent a number of temporary tax provisions, while temporarily extending other expired tax provisions. Earlier in the 114 th Congress, the House had considered proposals to make permanent certain expired tax provisions. Legislation was also reported out of the Senate Committee on Finance that would temporarily extend expired tax provisions. During the 113 th Congress, the House had also considered legislation to make permanent certain expired tax provisions. Before P.L. 114-113 was signed into law, there was other action on extenders in the 114 th Congress. The Senate Finance Committee reported the Tax Relief Extension Act of 2015 ( S. 1946 ), which would retroactively extend expired tax provisions for two years, through 2016. The House had passed legislation to make permanent eight of the temporary tax provisions that expired at the end of 2014 (see Table 3 ). America's Small Business Tax Relief Act of 2015 ( H.R. 636 ) would have made permanent the enhanced expensing allowances under Section 179 and also included the text from bills that would extend expired S corporation provisions (the Permanent S Corporation Built-in Gains Recognition Period Act of 2015 [H.R. 629] and the Permanent S Corporation Charitable Contribution Act of 2015 [H.R. 630]). Three expired charitable provisions were part of the America Gives More Act of 2015 ( H.R. 644 ): (1) the enhanced deduction for contributions of food inventory; (2) the provision allowing for tax-free distributions from Individual Retirement Accounts (IRAs) for charitable purposes; and (3) the special rules for contributions of capital gain real property for conservation purposes. The American Research and Competitiveness Act of 2015 ( H.R. 880 ) would have modified and made permanent the research tax credit. Legislation had also passed the House that would have made permanent the option to deduct state and local sales taxes in lieu of state and local income taxes ( H.R. 622 ). Taken together, these eight measures would have cost $317.5 billion over the 10-year budget window, excluding potential macroeconomic effects. In addition to the proposals to make permanent expired tax provisions that were passed in the House, the Committee on Ways and Means had reported other legislation during the 114 th Congress that would have made permanent other expired provisions (see Table 3 ). During the 113 th Congress, various bills were considered to either extend or make permanent certain tax extender provisions. Ultimately, a one-year "tax extenders" bill was passed and enacted late in the year (the Tax Increase Prevention Act of 2014 [P.L. 113-295] was signed into law on December 19, 2014). Earlier in the year, the Senate Finance Committee had reported a two-year extenders package, the Expiring Provisions Improvement Reform and Efficiency (EXPIRE) Act ( S. 2260 ). The EXPIRE Act proposed extending most expiring provisions for two years, through 2015. The House also considered legislation to make certain expiring tax provisions permanent during the 113 th Congress. As noted in Table 3 , the House passed legislation that would have made permanent nine provisions that are currently part of the tax extenders. Taken together, permanently extending these nine provisions would have reduced revenues by an estimated $511.4 billion over the 10-year budget window. Six of these nine provisions were included in the Jobs for America Act ( H.R. 4 ), which also passed the House in the 113 th Congress. Three other charitable-related provisions were passed as part of the America Gives More Act of 2014 ( H.R. 4719 ). The Committee on Ways and Means reported legislation during the 113 th Congress that would have made two additional international-related extender provisions permanent, although this legislation was not considered in the full House. Several provisions that had expired at the end of 2013 were not extended as part of the Tax Increase Prevention Act of 2014 ( P.L. 113-295 ). Two of these provisions would have been extended in the EXPIRE Act, but were not included in P.L. 113-295 : the health coverage tax credit and the credit for electric-drive motorcycles and three-wheeled vehicles. Both of these provisions have been extended in subsequent legislation. The health coverage tax credit had not been extended as part of past "tax extenders" legislation. The health coverage tax credit was first enacted, without an expiration date, as part of the Trade Act of 2002 ( P.L. 107-240 ). A January 1, 2014, termination date was enacted as part of an act to extend the Generalized System of Preferences in 2011 ( P.L. 112-40 ). The health coverage tax credit was modified and retroactively extended through December 31, 2019, as part of the Trade Preferences Extension Act of 2015 ( P.L. 114-27 ), signed into law on June 29, 2015. The other provision that was not extended in P.L. 113-295 , but would have been extended by the EXPIRE Act, was the credit for electric-drive motorcycles and three-wheeled vehicles. In recent years, a number of incentives have been available for various alternative technology vehicles. There are currently incentives available for plug-in electric vehicles. Incentives for most other alternative technology vehicles have expired. The credit for two-wheeled electric plug-in vehicles was extended through 2016 in P.L. 114-113 . Two other energy-related provisions were not extended past their January 1, 2014, termination date: the placed-in-service date for partial expensing of certain refinery property and the credit for energy efficient appliances. The EXPIRE Act did not propose extending either of these provisions. Two disaster-related provisions that expired at the end of 2013—one that provided tax-exempt bond financing authority for facilities in the New York Liberty Zone and another related to the replacement period for nonrecognition of gain for areas damaged by the 2008 Midwestern storms—were not extended in P.L. 113-295 . The EXPIRE Act also did not include an extension for these disaster-related provisions.

Summary: In the past, Congress has regularly acted to extend expired or expiring temporary tax provisions. Collectively, these temporary tax provisions are often referred to as "tax extenders." Fifty-two temporary tax provisions expired at the end of 2014. All of these provisions were either temporarily or permanently extended as part of the Consolidated Appropriations Act, 2016 (P.L. 114-113), signed into law on December 18, 2015. Unlike previous tax extenders legislation, P.L. 114-113 made a number of provisions permanent, and provided longer-term extensions for other provisions. This report provides a broad overview of the tax extenders. Congress had previously addressed tax extenders toward the end of the 113th Congress. The Tax Increase Prevention Act of 2014 (P.L. 113-295), signed into law on December 19, 2014, made tax provisions that had expired at the end of 2013 available to taxpayers for the 2014 tax year. The law extended most (but not all) provisions that had expired at the end of 2013. Most of the provisions in P.L. 113-295 had been included in previous "tax extender" packages. There are several reasons why Congress may choose to enact tax provisions on a temporary basis. Enacting provisions on a temporary basis provides legislators with an opportunity to evaluate the effectiveness of tax policies prior to expiration or extension. Temporary tax provisions may also be used to provide temporary economic stimulus or disaster relief. Congress may also choose to enact tax provisions on a temporary rather than permanent basis due to budgetary considerations, as the foregone revenue from a temporary provision will generally be less than if it were permanent. The provisions that expired at the end of 2014 are diverse in purpose, including provisions for individuals, businesses, the charitable sector, and energy-related activities. Among the individual provisions that expired are deductions for teachers' out-of-pocket expenses, state and local sales taxes, qualified tuition and related expenses, and mortgage insurance premiums. On the business side, under current law, the research and development (R&D) tax credit, the work opportunity tax credit (WOTC), the active financing exceptions under Subpart F, the new markets tax credit, and increased expensing and bonus depreciation allowances will not be available for taxpayers after 2014. Expired charitable provisions include the enhanced deduction for contributions of food inventory and provisions allowing for tax-free distributions from retirement accounts for charitable purposes. The renewable energy production tax credit (PTC) expired at the end of 2014, along with a number of other incentives for energy efficiency and renewable and alternative fuels. As discussed in this report, many of these provisions were made permanent in P.L. 114-113. Additional information on specific extender provisions may be found in other CRS reports, including the following: CRS Report R43510, Selected Recently Expired Business Tax Provisions ("Tax Extenders"), by [author name scrubbed], [author name scrubbed], and [author name scrubbed]; CRS Report R43688, Selected Recently Expired Individual Tax Provisions ("Tax Extenders"): In Brief, by [author name scrubbed] and [author name scrubbed]; CRS Report R43517, Recently Expired Charitable Tax Provisions ("Tax Extenders"): In Brief, by [author name scrubbed] and [author name scrubbed]; CRS Report R43541, Recently Expired Community Assistance-Related Tax Provisions ("Tax Extenders"): In Brief, by [author name scrubbed]; and CRS Report R43449, Recently Expired Housing Related Tax Provisions ("Tax Extenders"): In Brief, by [author name scrubbed].