The Tax Cuts and Jobs Act (TCJA) represents the most sweeping federal tax reform legislation in more than three decades. Signed into law in December 2017, the TCJA introduced substantial changes that affect both corporations and individual taxpayers across the United States. Understanding the key TCJA provisions is essential for business owners, tax professionals, and anyone filing a federal return, because many of these changes directly determine how much you owe, or save, each year. You can review the full law text through the IRS overview of the Tax Cuts and Jobs Act.
The law replaced the graduated corporate tax structure with a flat rate, nearly doubled the standard deduction for individuals, eliminated several popular itemized deductions, and created new incentives for domestic manufacturing and pass-through business income. Most individual provisions are set to expire after 2025 unless Congress acts to extend them, making this an especially important moment to review what the Tax Cuts and Jobs Act changed and what may revert.
Below is a detailed look at how the TCJA affects corporations and individuals, along with practical context on the provisions that matter most. Because the rules interact in complex ways across entity types and income levels, many filers benefit from coordinated tax advisory services when planning around them.
How the TCJA Changed Corporate Tax Rates
The single most prominent corporate change under the Tax Cuts and Jobs Act is the shift from a graduated rate structure, which ranged from 15% to 35%, to a flat 21% corporate tax rate. This rate reduction is permanent, meaning it does not expire in 2026 the way many individual provisions do. The flat rate simplified corporate tax calculations and brought the U.S. statutory rate closer to the average among other developed nations.
In addition to the rate cut, the TCJA eliminated the corporate alternative minimum tax (AMT). Before the law, corporations had to calculate their tax liability twice, once under the regular system and once under the AMT, and pay whichever amount was higher. Removing the corporate AMT reduced compliance costs and eliminated a layer of complexity that affected capital-intensive businesses most heavily.
Business Interest Expense and Entertainment Deduction Limits
The Tax Cuts and Jobs Act placed a new cap on the deduction for business interest expense, limiting it to 30% of a company’s adjusted taxable income. This provision was designed to discourage excessive leverage and applies broadly across industries, though certain small businesses and real estate operations may qualify for exceptions.
The law also fully eliminated the deduction for entertainment, amusement, and recreation expenses. Before the TCJA, businesses could deduct 50% of entertainment costs that were directly related to business activities. Under the new rules, no deduction is allowed for entertainment regardless of its business purpose, though the 50% deduction for business meals was preserved through 2025. The IRS addresses these limits in Publication 463 on travel, gift, and car expenses, which businesses should consult before claiming meal costs.
Net Operating Losses and Accelerated Depreciation Under the TCJA
Net operating loss (NOL) rules changed significantly under the TCJA provisions. For losses arising in tax years beginning after 2017, the maximum NOL deduction is limited to 80% of taxable income. The law also eliminated the ability to carry NOLs back to prior years, though it allowed indefinite carryforward. This change means businesses can no longer use a large loss to obtain a refund of taxes paid in a profitable prior year. Instead, they must carry that loss forward to offset future income.
On the investment side, the Tax Cuts and Jobs Act expanded bonus depreciation to allow businesses to immediately write off 100% of the cost of qualified depreciable assets placed in service after September 27, 2017. This accelerated depreciation provision, sometimes called “full expensing,” applied to both new and used property, a significant expansion from prior law. The 100% bonus depreciation began phasing down after 2022, declining by 20 percentage points per year.
The TCJA also expanded eligibility for the cash method of accounting. Previously limited to businesses with average annual gross receipts of $5 million or less, the threshold was raised to $25 million, allowing more mid-sized businesses to use the simpler cash method rather than the accrual method. Capital-intensive sectors such as manufacturing and real estate saw some of the largest planning effects from these depreciation and accounting changes.
International Tax Provisions and Export Incentives
The Tax Cuts and Jobs Act moved the U.S. from a worldwide tax system to a quasi-territorial system. Under the old rules, U.S. corporations owed tax on all income regardless of where it was earned. The TCJA introduced a 100% dividends-received deduction for the foreign-source portion of dividends from certain foreign subsidiaries, effectively exempting repatriated foreign earnings from U.S. tax.
The law also created an incentive for U.S. companies that sell goods and services abroad by effectively taxing foreign-derived intangible income (FDII) at a reduced rate. This provision was designed to encourage companies to keep intellectual property and related income within the United States rather than shifting it to low-tax jurisdictions.
TCJA Standard Deduction and Individual Tax Brackets
The most widely felt individual change under the Tax Cuts and Jobs Act was the near-doubling of the standard deduction. The TCJA standard deduction rose to $24,000 for married couples filing jointly, $18,000 for heads of household, and $12,000 for single filers. This increase, combined with the elimination of personal exemptions, was intended to simplify filing for millions of taxpayers by making the standard deduction more attractive than itemizing.
Individual income tax rates also dropped under the TCJA. The new brackets, 10%, 12%, 22%, 24%, 32%, 35%, and 37%, reflected reductions ranging from zero to four percentage points depending on the bracket. The top marginal rate fell from 39.6% to 37% for taxable income above certain thresholds.
The child tax credit doubled to $2,000 per qualifying child, with up to $1,400 refundable. The income phase-out threshold also increased substantially, allowing more middle- and upper-income families to claim the full credit.
Itemized Deduction Changes That Affect Individual Taxpayers
The Tax Cuts and Jobs Act significantly curtailed several itemized deductions. The new $10,000 cap on state and local tax (SALT) deductions, covering property taxes and either income or sales taxes on a combined basis, had the greatest impact on taxpayers in high-tax states like New York, New Jersey, and California.
The mortgage interest deduction was limited to debt of $750,000 for new loans (down from $1 million), and the deduction for interest on home equity debt was eliminated entirely. The personal casualty and theft loss deduction was repealed except in the case of federally declared disasters, and miscellaneous itemized deductions subject to the 2% adjusted gross income (AGI) floor, including unreimbursed employee expenses and investment advisory fees, were eliminated.
On the positive side, the TCJA removed the Pease limitation, which had phased out itemized deductions for higher-income taxpayers. It also lowered the AGI threshold for deducting medical expenses to 7.5% for the 2017 and 2018 tax years, providing temporary relief for taxpayers with significant healthcare costs.
Pass-Through Income Deduction and Other Individual TCJA Provisions
The Tax Cuts and Jobs Act created a new 20% deduction on qualified business income (QBI) earned through pass-through entities such as S corporations, partnerships, and sole proprietorships. This provision, found in Section 199A, was designed to give pass-through businesses a tax benefit comparable to the reduced corporate rate. However, the deduction comes with significant limitations for specified service trades or businesses (SSTBs), including law, accounting, health, and consulting, once taxable income exceeds certain thresholds.
The TCJA also repealed the Section 199 domestic production activities deduction, which had provided a 9% deduction on qualified production income. Other notable individual changes include the elimination of the moving expense deduction (except for active military), the increase in the cash charitable contribution limit from 50% to 60% of AGI, the expansion of 529 plan distributions to cover up to $10,000 per year in K-12 tuition expenses, and the doubling of the estate and gift tax exemption to approximately $11.2 million per individual in 2018.
The individual mandate penalty under the Affordable Care Act was also effectively repealed, with the penalty reduced to $0 for months beginning after December 31, 2018.
AMT Exemption Increases for Individuals
The alternative minimum tax was not eliminated for individuals as it was for corporations, but the TCJA significantly raised the AMT exemption amounts. The exemption increased to $109,400 for joint filers, $70,300 for singles and heads of household, and $54,700 for separate filers. The phase-out thresholds were also raised, which effectively removed many upper-middle-income taxpayers from AMT liability.
Frequently Asked Questions
What is the Tax Cuts and Jobs Act?
The Tax Cuts and Jobs Act is a federal tax reform law enacted in December 2017 that made sweeping changes to both corporate and individual taxation. It lowered the corporate tax rate to a flat 21%, nearly doubled the standard deduction, revised individual tax brackets, and introduced a new deduction for pass-through business income. Most individual TCJA provisions are scheduled to expire after 2025.
How did the TCJA change the corporate tax rate?
The TCJA replaced the graduated corporate tax rate structure, which ranged from 15% to 35%, with a flat 21% rate. This change is permanent and does not expire. The law also eliminated the corporate alternative minimum tax, simplifying compliance for businesses that previously had to calculate liability under two parallel systems.
What happened to the standard deduction under the TCJA?
The TCJA standard deduction nearly doubled, rising to $24,000 for married couples filing jointly, $18,000 for heads of household, and $12,000 for single filers. At the same time, personal exemptions were eliminated. This trade-off simplified filing for millions of taxpayers but reduced the benefit for large families who previously claimed multiple exemptions.
When do TCJA provisions expire?
Most individual Tax Cuts and Jobs Act provisions are set to expire after December 31, 2025. This includes the reduced individual tax rates, the increased standard deduction, the $10,000 SALT deduction cap, and the Section 199A pass-through deduction. Corporate provisions, including the flat 21% rate, are permanent and do not have a sunset date.
What is the Section 199A pass-through deduction?
Section 199A allows owners of pass-through businesses, such as sole proprietorships, partnerships, and S corporations, to deduct up to 20% of their qualified business income. The deduction is subject to limitations based on taxable income, the type of business, and W-2 wages paid. Service businesses in fields like law, accounting, and consulting face additional restrictions once income exceeds set thresholds.
How does the TCJA affect state and local tax deductions?
The Tax Cuts and Jobs Act capped the deduction for state and local taxes at $10,000 per return ($5,000 for married filing separately). This limit applies to the combined total of property taxes and either state income or sales taxes. Taxpayers in high-tax states were most affected, as many previously deducted well above $10,000 in state and local taxes each year.
