Section 179 Expensing
Section 179 of the Internal Revenue Code (26 U.S.C. § 179) allows businesses to immediately deduct the full cost of qualifying equipment, machinery, software, and other eligible property in the year it's placed in service — instead of depreciating it over years through MACRS. In 2026, the Section 179 deduction limit is $2,560,000, with a dollar-for-dollar phase-out beginning when total qualifying purchases exceed $4,090,000. This makes Section 179 most valuable for small and mid-sized businesses making moderate equipment purchases — large capital spenders who hit the phase-out ceiling find bonus depreciation (which has no dollar cap, though it is phasing down from 100%) more useful for very large investments. Eligible property includes tangible personal property (machinery, vehicles, computers), off-the-shelf software, qualified improvement property (certain interior commercial building improvements), and limited categories of real property. One important constraint: the Section 179 deduction cannot exceed the business's taxable income from active business activity for the year — unused amounts carry forward indefinitely. Unlike bonus depreciation (which applies automatically), Section 179 is elective: businesses choose to apply it and can deploy it strategically to maximize current-year tax benefit.
Current Law (2026)
Allows businesses to immediately deduct the full purchase price of qualifying equipment and software in the year placed in service, up to annual limits.
| Parameter | 2026 Value |
|---|---|
| Deduction limit | $2,560,000 |
| Phase-out threshold | $4,090,000 |
| Eligible property | Tangible personal property, off-the-shelf software, qualified improvement property, some real property |
Legal Authority
- 26 U.S.C. § 179 — Election to expense certain depreciable business assets
How It Works
Section 179 is a choice — it doesn't happen automatically. You elect it by completing Form 4562 and can apply the deduction to specific assets in specific amounts: you might elect Section 179 for 3 of 5 equipment purchases to exactly offset taxable income and let bonus depreciation handle the rest. This asset-by-asset, amount-by-amount control is Section 179's core advantage over automatic bonus depreciation. Your Section 179 deduction cannot exceed your taxable income from active business activity: if your business earned $150,000 and you purchased $300,000 in equipment, your maximum Section 179 deduction is $150,000 — the excess carries forward indefinitely to any future year with sufficient business income. The $2,560,000 deduction limit phases out dollar-for-dollar when total qualifying property placed in service exceeds $4,090,000 and is entirely eliminated above $6,650,000 in purchases — at that scale, businesses rely on bonus depreciation instead — deliberately targeting the benefit to small and mid-sized businesses.
For vehicles, passenger cars face strict § 280F "luxury auto" caps limiting first-year deduction to roughly $12,200 even with Section 179. Vehicles over 6,000 lbs GVW (trucks, SUVs, vans) have a higher Section 179 limit of $32,000 for 2026 — the provision often called the "SUV loophole," which Congress intentionally caps to prevent full immediate write-off of luxury SUVs. Bonus depreciation still applies to the remaining cost above $32,000, so a $70,000 heavy SUV used entirely for business can still be fully expensed in year one through the combined Section 179 + bonus depreciation approach. Used property has always qualified for Section 179 (bonus depreciation only extended to used property in 2017), so pre-owned equipment purchases qualify fully.
How It Affects You
If you're buying equipment or software for your business in 2026: Section 179 and 100% bonus depreciation now work together, giving you two overlapping tools for full first-year expensing. For most purchases, it doesn't matter which you use — the result is the same. Section 179 is preferable when you want to target specific assets (it's elective and asset-by-asset), or if you have business income you want to offset. Bonus depreciation is automatic (elected out if you don't want it) and can create a net loss — useful if you want to carry losses back or forward. For manufacturers, Section 179 works alongside broader manufacturing incentives like the CHIPS Act and IRA production credits. At a $2.56M Section 179 limit and 100% bonus depreciation, there's no practical reason for most small and mid-size businesses to capitalize and depreciate equipment over multiple years.
If you're buying a heavy SUV for your business: The Section 179 deduction for vehicles over 6,000 lbs GVW (gross vehicle weight) is capped at $32,000 for 2026 — you can take $32,000 in year one, then depreciate the remainder under MACRS. This is the "SUV loophole" as limited by Congress. The cap exists specifically because legislators didn't want businesses writing off $80,000 luxury SUVs entirely in year one. Note: this is a specific 179 limitation; bonus depreciation still applies to the remaining cost above the $32,000 cap, so the full vehicle cost can still be expensed in year one if combined.
If your business has taxable income below your equipment purchase: Section 179 cannot create a loss — it's limited to your business taxable income for the year. If you buy $300,000 of equipment but only have $100,000 in business income, you can deduct $100,000 via 179 and the remaining $200,000 carries forward. Bonus depreciation has no income limitation and can create a net operating loss that carries forward or back. For a business with low-income years followed by high-income years, timing equipment purchases to match with high-income years maximizes the tax benefit.
If you're a pass-through owner (S-corp, partnership, or sole proprietor): Section 179 deductions flow through to your personal return and can interact with the QBI deduction. Large 179 deductions reduce your qualified business income — which in turn reduces your QBI deduction. Model the combined effect of 179 + bonus depreciation against your QBI deduction before choosing to accelerate all depreciation in a single year. Self-employed owners may also want to coordinate with self-employment tax planning, since large 179 deductions reduce net earnings subject to SE tax.
State Variations
Section 179 is a federal provision, but most states have their own version with very different — often much lower — limits. California is the most important example:
California — its own § 179 with much lower limits: California does not conform to the federal $2,560,000 Section 179 deduction limit. California has its own expensing election, but the CA limit is approximately $25,000 (indexed separately and far below the federal amount). A business taking a $500,000 Section 179 deduction on the federal return can only claim approximately $25,000 on the California return — leaving $475,000 to be depreciated over the normal MACRS schedule for CA purposes. This creates a significant multi-year tracking burden and a large year-one CA state tax liability relative to the federal benefit. At CA's corporate rate of 8.84% or individual rates up to 13.3%, the excess federal deduction creates substantial additional CA tax in year one, recovered slowly through future CA depreciation.
New Jersey: NJ does not conform to the federal Section 179 limits and uses its own expensing rules based on older law. NJ businesses deducting large amounts via 179 federally will face significant add-back requirements on NJ returns.
New York: NY generally conforms to federal Section 179 for corporations; individual taxpayers (partners, S-corp shareholders) may face different treatment. NY conformity has evolved — verify current-year treatment.
Pennsylvania: PA has its own depreciation rules and does not conform to expanded federal Section 179 amounts. PA businesses must track federal and PA book value separately.
Most other states: The majority of states with income taxes conform to federal Section 179, either by explicit conformity or by reference to the IRC. For these states, the federal deduction equals the state deduction with no add-back required.
Multi-state businesses: For businesses operating in California or New Jersey alongside other states, the Section 179 deduction must be apportioned — only the portion of income attributable to a non-conforming state drives the add-back. A business with 30% of income in California taking a $300,000 Section 179 deduction federally would add back approximately $82,500 on the CA return (30% × ($300,000 − $25,000 CA limit)). State conformity tracking for Section 179 is a perennial issue in multi-state tax compliance.
Implementing Regulations
- 26 CFR Part 1 — Income tax regulations (SS 1.179-0: table of contents; SS 1.179-1 through 1.179-6: election rules, limitations on deduction amount, dollar/investment limits, carryforward)
Pending Legislation (119th Congress)
- HR 1990 (Rep. Estes, R-KS) — American Innovation and R&D Competitiveness Act of 2025. Would let firms immediately deduct research costs or amortize certain capitalized R&E over 60 months and align deduction rules with the R&D tax credit. Status: Introduced.
Recent Developments
- Section 179 and 100% bonus depreciation now work together in 2026: With 100% bonus depreciation restored for property acquired and placed in service after January 19, 2025 (via the One Big Beautiful Bill Act), businesses have two overlapping immediate-expensing tools. Section 179 remains valuable because it allows targeted control — businesses can apply it to specific assets and carry forward unused deductions. Bonus depreciation applies automatically (unless elected out) and has no income limitation. For 2026 equipment purchases, most businesses will max out 179 first ($2,560,000 limit), then let bonus depreciation cover any remaining eligible costs.
- 179 deduction limit indexed for inflation — 2026 values confirmed: The $2,560,000 deduction limit and $4,090,000 phase-out threshold are the current indexed figures for 2026. These have grown substantially from the pre-TCJA era ($500,000 limit in 2016). The phase-out structure means the benefit is fully preserved for businesses spending up to $4,090,000 and completely eliminated above $6,650,000 — targeting the break-even benefit to mid-size capital investments, not large industrial deployments.
- SUV limitation holds at $32,000 for 2026: The SUV Section 179 cap (for vehicles over 6,000 lbs GVW) remains $32,000 for 2026 — unchanged from prior years. This limit is a specific anti-abuse provision targeting luxury SUV write-offs. Passenger vehicles have even tighter limits under the "luxury auto" caps in IRC § 280F. Businesses comparing vehicle options should model the depreciation schedule difference before assuming a heavier vehicle generates a better deduction.
- IRC § 174 R&D amortization still broken — no fix passed: Since 2022, companies must amortize domestic R&D expenses over 5 years (15 years for foreign) rather than deducting them immediately. This indirectly affects how 179 and bonus depreciation interact with R&D-heavy capital investments. The American Innovation and R&D Competitiveness Act (HR 1990, S 1639) would restore immediate deductibility, but as of early 2026 it has not passed. Manufacturers and software companies planning major equipment investments should model their 174 exposure alongside 179 and bonus depreciation. Companies investing in R&D-intensive equipment should also evaluate the R&D tax credit as a complementary benefit.