You bought $40,000 of equipment this year — a work truck upgrade, new laptops, shop tools. Whether that $40,000 lands on this year's return as a full deduction or trickles out over the next seven years comes down to which part of a two-page IRS form you fill in, and in what order. Get the order wrong and you depreciate basis you already expensed. Miss one checkbox and bonus depreciation you never asked for wipes out a deduction you wanted to save for a higher-income year. Form 4562, Depreciation and Amortization, is where all of those decisions get recorded, so this post walks through it part by part: the Section 179 election, bonus depreciation, regular MACRS, the summary, listed property, and amortization.
What Form 4562 is and when you must file it
Form 4562 is the supporting form behind the depreciation line on your return — line 13 of Schedule C, the depreciation lines of Forms 1065, 1120-S, and 1120, and line 18 of Schedule E for rental property. You attach it in any year you do one of four things: claim depreciation on property placed in service during the year, make the Section 179 election, begin amortizing a cost during the year, or claim depreciation on listed property (vehicles and similar mixed-use assets) no matter when you placed it in service.
The mirror image matters just as much. If all you are doing is continuing depreciation or amortization on non-listed property from a prior year, you do not file Form 4562 at all — you enter the number directly on your return. Many owners file the form every year out of habit; the instructions say you can skip it in quiet years.
One more scope note before the parts: land is never depreciable, inventory is never depreciable, and property placed in service and disposed of in the same year generally takes no depreciation. Everything below assumes business property with a determinable useful life that you actually put to work during the year.
Part I: the Section 179 election to expense it now
Part I is where you elect under Section 179 to deduct the cost of qualifying property in the year you place it in service instead of capitalizing it. For 2026 the ceiling is $2,560,000 of expensed cost, and it phases out dollar for dollar once you place more than $4,090,000 of qualifying property in service during the year. (For 2025 returns the figures were $2,500,000 and $4,000,000.) List each electing asset, its cost, and the elected amount on the detail lines; the computed deduction lands on line 12.
Four limits shape every Section 179 decision:
- Taxable income limit. Your Section 179 deduction cannot exceed the taxable income from your active trades or businesses. Unlike bonus depreciation, Section 179 cannot create or deepen a loss — but the unused amount is not lost. It carries forward indefinitely to future years, which makes the election safe to claim in a thin year.
- Business-use test. The property must be used more than 50% for business in the year you place it in service. At 50% or below, no Section 179 at all.
- Purchased, not gifted. The property must be acquired by purchase — new or used both qualify — from an unrelated party. Inherited property and gifts from relatives are out.
- Listed property cap for SUVs. Heavy SUVs (over 6,000 pounds gross vehicle weight) escape the passenger-auto caps described in Part V, but Congress capped their Section 179 slice specifically: $31,300 for 2025 and $32,000 for 2026. The remaining basis can still go through bonus depreciation, which has no cap.
Section 179 is opt-in, asset by asset, on a timely filed return. That selectivity is its real power: you can expense the delivery van while depreciating the laptops normally, tuning this year's deduction to this year's income. Bonus depreciation, as the next part shows, works the opposite way.
Part II: bonus depreciation and other depreciation
Part II starts with line 14, the special depreciation allowance — bonus depreciation under Section 168(k). For property acquired after January 19, 2025 and placed in service, the One Big Beautiful Bill Act permanently restored the 100% rate, ending the phase-down that had cut it to 60% for 2024 and was scheduled to drop it to 40% for 2025 and 20% for 2026. Qualified property is generally MACRS property with a recovery period of 20 years or less, plus qualified improvement property and certain other assets; used property qualifies as long as it is new to you and bought from an unrelated party.
Three contrasts with Section 179 decide which tool fits:
- Bonus is automatic. It applies to every qualifying asset in a class unless you affirmatively elect out for the whole class on a timely filed return, with a statement attached. Section 179 never happens by accident; bonus happens unless you stop it.
- Bonus has no dollar cap and no income limit. There is no $2,560,000 ceiling, no phase-out, and no taxable-income test. Bonus can create a net operating loss, which is exactly why some owners in a low year elect out and save the deductions.
- Bonus follows Section 179. The ordering is fixed by statute: subtract any Section 179 amount first, apply bonus to the remaining basis, then compute regular MACRS on whatever is left.
That ordering produces the classic stacking example. Buy a $30,000 machine, elect $10,000 of Section 179 on it in Part I, and Part II applies 100% bonus to the remaining $20,000 — the full $30,000 deducted this year through two lines. Elect no Section 179 and bonus alone takes the whole $30,000. The stacking matters when you want only a partial first-year write-off: Section 179 gives you the dial, bonus takes the rest.
The trap to watch is the acquisition date. Property bought under a written binding contract entered into before January 20, 2025 stays on the old phase-down rates even if you placed it in service later in 2025. If you signed for equipment in late 2024 and took delivery in 2025, your bonus rate is 40%, not 100% — and your software may or may not catch that from the dates you enter.
Line 16 picks up everything else: depreciation on older ACRS property and any other depreciation not reported on the lines above it. If none of those apply, line 16 stays blank.
Part III: regular MACRS depreciation
Part III is the MACRS workhorse, in three sections. Section A reports depreciation on assets placed in service in earlier years — the continuing schedules from prior returns. Section B lists assets placed in service this year under the General Depreciation System (GDS) by recovery period and method. Section C does the same for assets you elect onto the Alternative Depreciation System (ADS), which uses longer lives and straight-line.
For most small-business property, GDS assigns the method automatically: 200% declining balance for 3-, 5-, 7-, and 10-year property, 150% declining balance for 15- and 20-year property, and straight-line for nonresidential real property over 39 years and residential rental property over 27.5 years. The half-year convention treats every asset as placed in service at midyear regardless of the actual month — unless more than 40% of your year's additions went into service in the final quarter, which triggers the mid-quarter convention and trims the first-year deduction. That mid-quarter rule is the quiet reason December equipment splurges sometimes disappoint.
ADS is rarely the first choice because it stretches deductions out, but two situations force or favor it: listed property at 50% or less business use must use ADS straight-line, and electing real-estate businesses avoiding the interest deduction limit must depreciate their rental real estate under ADS. You make the ADS election on a timely filed return — in practice by selecting ADS for the asset in your software, which reports it in Section C — and it is irrevocable.
Part IV: the summary
Part IV is one line — line 22 — that adds the Section 179 deduction, bonus and other depreciation, regular MACRS, and the listed-property total carried from Part V. That total is the number that flows to your return's depreciation line. There is nothing to strategize here; its job is reconciliation. If your return's depreciation deduction does not tie to Form 4562 line 22 (plus any continuing depreciation you entered directly), something got transcribed wrong, and that mismatch is one of the first things an examiner checks.
Part V: listed property and the business-use substantiation
Part V covers listed property: passenger automobiles, other transportation property, and property used for entertainment, recreation, or amusement. (Computers and peripherals used to be listed property too, but Congress removed them in 2018 — your office laptop is ordinary 5-year property now.) The sections split on the 50% line: Section A reports listed property used more than 50% for qualified business use, with per-vehicle detail lines for mileage and business-use percentages; Section B reports listed property at 50% or below; and Section C asks whether you have evidence and written policies supporting the percentages you claim.
The 50% line runs through everything here. Business use above 50% in the placed-in-service year unlocks Section 179, bonus, and regular MACRS. At 50% or below you get none of those — only ADS straight-line — and if business use starts above 50% and later drops to 50% or below, you recapture the excess: the difference between what you deducted and what ADS straight-line would have allowed comes back as income. That recapture is the reason mixed-use vehicles deserve a mileage log from day one, not a reconstruction at tax time.
Passenger automobiles under 6,000 pounds carry a second ceiling on top of everything: the Section 280F luxury-auto limits, inflation-adjusted every year. For vehicles placed in service in 2026, Revenue Procedure 2026-15 caps annual depreciation at $20,300 in year one with bonus depreciation ($12,300 without), then $19,800, $11,900, and $7,160 per year after. A $55,000 sedan used 100% for business still deducts only $20,300 in year one — the cap binds no matter which method you use. Vehicles over 6,000 pounds gross vehicle weight are not passenger automobiles at all, which is why the heavy-SUV discussion in Part I matters: same showroom, completely different tax math.
Part VI: amortization of intangibles and startup costs
Part VI, lines 42 through 44, amortizes costs that have no physical substance. The biggest category is Section 197 intangibles acquired with a business: goodwill, going-concern value, workforce in place, customer lists, licenses, and covenants not to compete. Every one of them amortizes straight-line over 15 years starting with the month of acquisition — even a three-year non-compete gets a 15-year schedule. Self-created intangibles generally cannot be amortized this way; the 15-year clock is for intangibles you bought.
The category more small businesses actually meet is startup costs under Section 195: the market surveys, training, advertising, and professional fees you incur before the business opens its doors. You may deduct up to $5,000 immediately (reduced dollar for dollar once startup costs exceed $50,000) and amortize the remainder over 180 months starting with the month active business begins. The election is deemed made — you get this treatment automatically unless you affirmatively opt out — and organizational expenditures for forming a corporation or partnership follow nearly identical rules under their own sections.
File Form 4562 in the year amortization begins; like depreciation, continuing amortization on its own does not require the form.
Keeping the book side straight
Your tax return and your books will now disagree, and that is expected. Section 179 and bonus depreciation are tax-only accelerations — your balance sheet should still show the asset and depreciate it over its real useful life, so your monthly profit means something and a lender sees the equipment you own. The clean way to hold both truths is one fixed-asset account per significant asset and a monthly book depreciation entry:
2026-03-15 * "Buy shop compressor, placed in service"
Assets:Fixed:Compressor-01 30000.00 USD
Assets:Checking -30000.00 USD
2026-03-31 * "March book depreciation, compressor (84-month life)"
Expenses:Depreciation:Equipment 357.14 USD
Assets:Fixed:Compressor-01 -357.14 USDThe tax return takes its $30,000 through Form 4562; the books recognize $357.14 a month. The per-asset account is what lets you prove basis, compute gain or loss on sale, and survive the recapture math if business use ever drops. If you keep your ledger in plain text, the documentation covers account structure and balance assertions in more depth — asserting each fixed-asset balance monthly is what catches a missed or doubled depreciation entry before year-end.
Common mistakes that cost real money
- Depreciating the full basis after expensing part of it. Section 179, then bonus, then MACRS — each step applies to the basis remaining after the last. Running MACRS on the original cost double-counts.
- Assuming 100% bonus on early-2025 acquisitions. The binding-contract date, not the placed-in-service date, controls the rate for property ordered before January 20, 2025.
- Electing out of bonus without the statement. The class-wide opt-out needs an affirmative election on a timely filed return. No statement, no opt-out.
- Depreciating land. The building depreciates; the land under it never does. Allocate the purchase price between them at acquisition — the property tax assessment ratio is a common starting point.
- Ignoring the mid-quarter convention. Place most of the year's equipment in service in October through December and the default half-year convention no longer applies.
- Reconstructing vehicle logs in April. Listed-property deductions need contemporaneous records of business versus personal use. A calendar rebuilt from memory is exactly what fails under examination.
- Forgetting recapture on sale or conversion. Section 179 and bonus deductions reduce basis. Sell the asset later and depreciation recapture taxes part of the gain as ordinary income — track basis per asset so the sale computation is arithmetic, not archaeology.
Your year-end Form 4562 checklist
Pull your fixed-asset listing before December: every asset placed in service this year with its date, cost, business-use percentage, and contract date for anything ordered late last year or early this year. Decide the Section 179 amounts asset by asset against your projected taxable income, decide whether bonus helps or hurts this year's bracket before accepting the default, confirm no vehicle needs a log you do not have, and make sure land and building costs were split on any real estate purchase. Bring that package to your preparer — or into your software — and each part of the form becomes transcription instead of guesswork.
