For corporate taxpayers, 2026 remains a major planning year because the IRS’s current guidance continues to reflect the One, Big, Beautiful Bill Act (Pub. L. 119-21) and its changes to Section 179, bonus depreciation, domestic R&D expensing, Section 163(j), and the standard mileage rate. The result is a tax environment where capital investment, research spending, financing decisions, and even vehicle policy can materially affect taxable income. (irs.gov)
Key Takeaways for Tax Year 2026
| Deduction / Rule | 2026 Rule | Why It Matters |
|---|---|---|
| Section 179 | Maximum deduction of $2,560,000; phaseout begins at $4,090,000; certain SUVs capped at $32,000. | Lets businesses expense qualifying equipment faster, subject to limits. |
| Bonus depreciation | Current IRS guidance provides a permanent 100% additional first-year depreciation deduction for eligible property acquired after Jan. 19, 2025. (irs.gov) | Can accelerate deductions on qualifying assets beyond Section 179 capacity. |
| Domestic R&D expensing | Domestic research and experimental expenditures are currently deductible for tax years beginning after Dec. 31, 2024; foreign R&E remains amortized over 15 years. (irs.gov) | Improves cash flow for innovation-heavy businesses. |
| Business interest expense | ATI now uses EBITDA; small-business exemption generally applies when average annual gross receipts are $31 million or less for the prior 3 years. (irs.gov) | Capital-intensive businesses can deduct more interest. |
| Mileage | Business standard mileage rate is 72.5 cents per mile in 2026. (irs.gov) | Update employee reimbursement and policy rates. |
| Meals | Business meals generally remain 50% deductible. (irs.gov) | Substantiation still matters. |
| CAMT | CAMT generally applies to corporations with average annual AFSI exceeding $1 billion. (irs.gov) | Large corporations need separate modeling and Form 4626 review. |
1. Section 179 Expensing in 2026
The Section 179 deduction remains one of the most useful tools for business owners buying equipment, software, or other qualifying assets. For tax years beginning in 2026, the IRS states that the maximum Section 179 expense deduction is $2,560,000, and that amount is reduced dollar-for-dollar once the cost of qualifying property placed in service during the year exceeds $4,090,000. The maximum amount for certain sport utility vehicles is $32,000.
Just as important, Section 179 is subject to a taxable income limitation. In other words, a business generally cannot use Section 179 to create or increase a loss beyond the allowable rules. That makes timing, taxable income, and asset placement in service critical planning points.
Planning Example: A Large Equipment Purchase
If TechMfg Corp buys $3,000,000 of qualifying equipment in 2026, the company may be able to expense up to $2,560,000 under Section 179, subject to the taxable income limitation. The remaining basis may then be eligible for bonus depreciation if the property qualifies. That combination is often the most efficient way to accelerate deductions on a large capital purchase. (irs.gov)
2. Bonus Depreciation Remains a Major 2026 Tool
Current IRS guidance under the OBBBA provides a permanent 100% additional first-year depreciation deduction for eligible depreciable property acquired after January 19, 2025. That means qualifying businesses can still write off a substantial amount of property cost quickly, especially after Section 179 limits are reached. (irs.gov)
Bonus depreciation is especially important for businesses with large capital budgets, because it can help absorb the remaining basis of qualified property that was not fully deducted under Section 179. In practical terms, many taxpayers coordinate the two rules rather than choosing only one. (irs.gov)
3. Research and Development: Domestic R&E Is Currently Deductible
One of the biggest corporate deductions in 2026 is still domestic research and experimental expenditure treatment. The IRS’s current OBBBA guidance says taxpayers may deduct domestic research or experimental expenditures for taxable years beginning after December 31, 2024. Foreign research and experimental expenditures, by contrast, remain capitalized and amortized over 15 years. Transition rules and selection procedures are available in current IRS guidance. (irs.gov)
This is a major cash-flow change for innovation-heavy businesses, because it allows companies to recover the cost of domestic development spending much faster than the old amortization model. (irs.gov)
Planning Example: A Domestic Lab Budget
If BioGen Inc. spends $2,000,000 on domestic research in 2026, the company can generally deduct the full amount currently, rather than spreading the deduction over several years. That can materially reduce taxable income in the year the expense is incurred. (irs.gov)
4. Business Interest Expense Under Section 163(j)
Business interest expense remains an important deduction for leveraged companies. Under current IRS guidance, the Section 163(j) calculation now uses EBITDA for adjusted taxable income, which is generally more favorable for capital-intensive businesses than an EBIT-based limitation. (irs.gov)
The small-business exemption also remains critical. A business generally qualifies as a small business taxpayer if it has average annual gross receipts of $31 million or less for the three prior tax years, and is not a tax shelter. (irs.gov)
Why This Matters
If a company exceeds the small-business threshold, its interest deduction planning becomes more sensitive to debt structure, depreciation schedules, and acquisition timing. If it is at or below the threshold, the Section 163(j) limitation may not apply at all. (irs.gov)
5. Operational Deductions: Meals and Vehicles
Business Meals
Business meals generally remain 50% deductible in 2026 when the taxpayer or employee is present and the food or beverages are not lavish or extravagant. Proper substantiation is still essential. (irs.gov)
Standard Mileage Rate
For 2026, the IRS sets the optional business standard mileage rate at 72.5 cents per mile. Businesses that reimburse employees or track owner-operator mileage should update internal policies to match the current rate. (irs.gov)
Why These Smaller Deductions Still Matter
Even though meals and mileage do not usually create the same dramatic savings as asset expensing or R&D deductions, they are recurring deductions that can add up quickly across the year. They also tend to be audit-sensitive, so documentation matters. (irs.gov)
6. Corporate Alternative Minimum Tax (CAMT)
Large corporations still need to model CAMT. The IRS states that CAMT generally applies to corporations with average annual AFSI exceeding $1 billion, and the tax is generally 15% of adjusted financial statement income, subject to the CAMT rules and credits. (irs.gov)
For companies near the threshold, CAMT modeling should be done before year-end rather than after the return is prepared. The current IRS guidance for Form 4626 continues to evolve, so large corporate taxpayers should confirm their status each year. (irs.gov)
7. Common Pitfalls and Mistakes
1) Missing the Section 179 phaseout threshold
The 2026 Section 179 deduction does not stop at the same point it did in the old article. The current phaseout begins at $4,090,000, not $4,000,000.
2) Using the wrong mileage rate
The 2025 business mileage rate of 70 cents per mile is outdated for 2026. The current business rate is 72.5 cents per mile. (irs.gov)
3) Forgetting foreign R&E rules
Domestic research can be currently deducted, but foreign research and experimental expenditures are still amortized over 15 years. That distinction matters for multinationals and companies with offshore development teams. (irs.gov)
4) Assuming all equipment purchases qualify for immediate expensing
Section 179, bonus depreciation, and the taxable income limitation do not apply the same way to every asset. The asset must be qualifying property and must be properly placed in service. (irs.gov)
5) Ignoring CAMT because your regular tax liability is low
CAMT is based on financial statement income, not just book tax expense. Large corporations can have CAMT exposure even when their regular tax posture looks favorable. (irs.gov)
FAQ
What is the 2026 Section 179 deduction limit?
For tax years beginning in 2026, the maximum Section 179 deduction is $2,560,000, and the deduction begins to phase out when qualifying property placed in service exceeds $4,090,000. The SUV cap is $32,000.
Does bonus depreciation still exist in 2026?
Yes. Current IRS guidance under the OBBBA provides a permanent 100% additional first-year depreciation deduction for eligible depreciable property acquired after January 19, 2025. (irs.gov)
Can domestic research costs still be deducted immediately?
Yes. Under current IRS guidance, domestic research and experimental expenditures are deductible for tax years beginning after December 31, 2024. Foreign R&E remains subject to 15-year amortization. (irs.gov)
What is the 2026 business mileage rate?
The IRS set the 2026 business standard mileage rate at 72.5 cents per mile. (irs.gov)
Who needs to worry about CAMT?
CAMT generally applies to corporations with average annual AFSI exceeding $1 billion. Large corporations should review Form 4626 and related current IRS guidance each year. (irs.gov)
What is the small-business exemption under Section 163(j)?
A taxpayer generally qualifies as a small-business taxpayer if it has average annual gross receipts of $31 million or less for the prior three tax years, and is not a tax shelter. (irs.gov)
Conclusion
The 2026 corporate deduction landscape is still heavily shaped by the OBBBA and the IRS’s current guidance. The biggest planning opportunities remain Section 179, 100% additional first-year depreciation, immediate domestic R&D expensing, and the more favorable EBITDA-based Section 163(j) calculation. At the same time, corporations should not overlook “smaller” deductions like meals and mileage, because those rules are still active and still audit-sensitive. (irs.gov)
For large corporate taxpayers, CAMT remains a separate planning layer, and for equipment-heavy businesses, the correct combination of Section 179 and bonus depreciation can materially change the year’s tax outcome. As always, the best result comes from modeling these deductions before year-end rather than after the return is prepared. (irs.gov)
Disclaimer: This article is provided for informational and educational purposes only and does not constitute legal, accounting, or professional tax advice. Tax laws and IRS guidance can change, and the correct treatment depends on your specific facts and circumstances. Please consult a qualified tax professional before making tax-planning or filing decisions.
