Form 4562 Line 11: The Taxable Income Limitation

Line 11 of Form 4562 is where the taxable income limitation on Section 179 gets applied: you enter the smaller of your reduced dollar limit from Line 5 or your aggregate taxable income from all trades or businesses you actively conduct during the year.¹ The Section 179 deduction cannot create or increase a net operating loss, so Line 11 is the gate that stops your write-off at the point your income runs out. Anything you elected above that number does not vanish; it carries forward.

What Line 11 Actually Caps

Line 11 is the last of the three limits Part I of Form 4562 imposes. Line 1 sets the statutory dollar ceiling ($2,560,000 for 2026). Lines 2 through 5 reduce that ceiling if your total qualifying purchases push past the $4,090,000 investment phase-out threshold. Line 11 then overlays an income test on whatever survives.²

The rule is simple: your Section 179 deduction for the year cannot exceed the aggregate taxable income you derived from the active conduct of any trade or business.³ Whichever is smaller — the Line 5 amount or your active business income — is what you write on Line 11.

How To Compute the Taxable Income Figure

The taxable income you use on Line 11 is not the taxable income line on your return. It is a purpose-built figure, calculated before certain deductions and limited to active business activity. The computation depends on the entity filing the form.

Individuals. Aggregate taxable income from all trades or businesses you actively conduct, plus all wages, salaries, and tips. Compute it before the Section 179 deduction itself, before the deduction for one-half of self-employment tax, and before any net operating loss deduction.¹
Partnerships. The partnership’s total items of income and expense described in Section 702(a) from actively conducted trades or businesses, excluding credits, tax-exempt income, the Section 179 deduction, and guaranteed payments.
S corporations. Total items of income and expense described in Section 1366(a) from actively conducted trades or businesses, excluding credits, tax-exempt income, the Section 179 deduction, and compensation paid to shareholder-employees.
C corporations. Taxable income before the Section 179 deduction, net operating loss deduction, and special deductions, limited to income from actively conducted businesses.

Including wages for individuals is the detail most people miss. If you have a day job and a side business, your W-2 earnings count toward the Line 11 cap, which often means a small business can absorb a large Section 179 election it couldn’t support on its own profit.

What “Actively Conducted” Means

Income only counts on Line 11 if it comes from a trade or business in which you meaningfully participate in management or operations. Passive investment does not qualify. This is the reason rental real estate typically fails to support a Section 179 deduction: unless the rental rises to the level of a trade or business you materially participate in, its income cannot feed Line 11 and its property is not eligible for Section 179 in the first place.⁴

If you run more than one business, aggregate the income from all of them. The Line 11 cap applies to you as a taxpayer, not per business, and the resulting Line 12 deduction is then allocated among your activities.

Where Line 11 Fits in Part I

The Line 11 number does not itself become your deduction. It is one of two inputs to Line 12, the actual allowable deduction. Here is how the numbers flow:

Line 5 gives you the dollar limit after any investment phase-out.
Line 10 totals the amount you have elected to expense across all assets you listed on Lines 6 and 7.
Line 11 is the smaller of Line 5 or your active business taxable income.
Line 12 is the smaller of Line 10 or Line 11. That is your Section 179 deduction for the year.¹

So Line 11 controls the deduction only when your income is the binding constraint. If Line 10 is smaller than Line 11, the income limit had capacity to spare and Line 11 does no work that year.

What Happens to the Amount Above Line 11

If you elected to expense more on Line 10 than Line 11 allows, the excess goes on Line 13 as a carryforward.⁵ The carryforward is indefinite. In a future year, it is deductible to the extent you have unused Section 179 capacity after applying that year’s dollar limit and any new elections. If carryforwards have accumulated from more than one prior year, the oldest year comes off first.

Worked Example

Assume your business places $4,200,000 of qualifying equipment in service during 2026 and your active business taxable income is $1,800,000.

Line 1: $2,560,000
Line 2: $4,200,000
Line 3: $4,090,000
Line 4: $110,000 (Line 2 minus Line 3)
Line 5: $2,450,000 (Line 1 minus Line 4)
Line 10: $2,450,000 (you elect the full reduced dollar limit)
Line 11: $1,800,000 (smaller of $2,450,000 or your $1,800,000 of active business income)
Line 12: $1,800,000 (smaller of Line 10 or Line 11)
Line 13: $650,000 carryforward

Income was the binding constraint. The $650,000 gap between what you elected and what your income supported carries to 2027.

The Pass-Through Wrinkle

For partnerships and S corporations, the Line 11 test applies twice, and this is where people trip. The entity computes its own Line 11 using its active business income and produces a Line 12 deduction, which it then allocates to owners through Box 12 of Schedule K-1.⁶⁷ Each owner then plugs that allocated amount into Part I of their own Form 4562, where Line 11 is retested against the owner’s personal active business income (including wages, for individuals).

A partner whose personal Line 11 is lower than their allocated share ends up with a carryforward on the individual return even though the partnership had plenty of income at the entity level. Owners of multiple pass-throughs need to add up the allocations before checking whether their personal income supports the total.

When Income Is Your Bottleneck, Consider Bonus Depreciation

The taxable income limit is the one Section 179 constraint that bonus depreciation does not share. Bonus depreciation has no income cap and can create or increase a net operating loss. For property acquired and placed in service after January 19, 2025, bonus depreciation is at 100% under the One, Big, Beautiful Bill Act.⁸

Section 179 is applied first; whatever basis remains is eligible for bonus depreciation.¹ A business expecting a loss year, or one whose Line 11 will bite hard, may prefer to elect less on Section 179 and let bonus depreciation do the work. Profitable businesses that clear the income test comfortably tend to prefer Section 179 for the flexibility to choose exactly which assets and how much of each asset’s cost to expense.

1
Internal Revenue Service. Instructions for Form 4562
2
Office of the Law Revision Counsel. 26 USC 179 – Election to Expense Certain Depreciable Business Assets
3
eCFR. 26 CFR 1.179-2 – Limitations on Amount Subject to Section 179 Election
4
Internal Revenue Service. Publication 946 – How To Depreciate Property
5
eCFR. 26 CFR 1.179-3 – Carryover of Disallowed Deduction
6
Internal Revenue Service. Partner’s Instructions for Schedule K-1 (Form 1065)
7
Internal Revenue Service. Shareholder’s Instructions for Schedule K-1 (Form 1120-S)
8
Internal Revenue Service. One, Big, Beautiful Bill Provisions