Depreciation & Section 179

What is the US MACRS depreciation framework?

The Modified Accelerated Cost Recovery System (MACRS) under IRC §168 is the standard US business-asset depreciation framework. MACRS classifies assets into recovery-period classes (3, 5, 7, 10, 15, 20, 25, 27.5, 39 years) based on asset type, with declining-balance depreciation methods (200 percent / 150 percent declining balance) switching to straight-line for the optimal year. Common asset-class examples: 5-year (computers, office equipment, vehicles); 7-year (office furniture, fixtures); 15-year (qualified improvement property post-2017 fix in CARES Act); 27.5-year (residential rental real estate); 39-year (non-residential real estate). The MACRS framework is supplemented by two principal first-year-expensing accelerators that have substantially reshaped US business-asset tax treatment over the past decade.

How does Section 179 first-year expensing work?

IRC §179 permits taxpayers to elect first-year expensing of qualifying business-asset purchases — fully deducting the asset cost in the year placed in service rather than depreciating it over the MACRS recovery period. 2025 limits: maximum §179 deduction USD 1,220,000 (indexed annually); investment-limit phaseout begins at USD 3,050,000 of total qualifying purchases (the deduction is reduced dollar-for-dollar above the phaseout, eliminating the deduction at USD 4,270,000 of purchases). Eligible property: tangible personal property (machinery, equipment, vehicles, computers, office furniture); off-the-shelf software (qualifying); qualified real property (qualified improvement property + roofs / HVAC / fire-and-alarm systems / security systems on non-residential real property post-TCJA additions); excludes land, intangible non-software assets, and pre-2018 categories. Limitations: §179 deduction cannot exceed the taxpayer's aggregate trade-or-business taxable income for the year — disallowed amount carries forward to subsequent years. The §179 deduction is taxable income for many state-conformity purposes — material variation by state. SUV and luxury-vehicle separate caps apply (§179(b)(5) and §280F).

What is bonus depreciation under §168(k)?

Bonus depreciation under IRC §168(k) provides additional first-year depreciation on qualifying property — separate from §179 and applied after §179. The 2017 TCJA increased bonus depreciation to 100 percent for property placed in service from 28 September 2017 through 31 December 2022; the post-2022 phasedown schedule: 80 percent for 2023; 60 percent for 2024; 40 percent for 2025; 20 percent for 2026; 0 percent from 2027 absent legislation. The post-2024 election cycle has produced multiple legislative proposals to extend or restore 100 percent bonus depreciation; practitioners should monitor for legislative action before year-end planning. Eligible property: tangible personal property with MACRS recovery period of 20 years or less; qualified film/TV/live-theatrical-production property; qualified improvement property; specified plants. Mechanism: bonus depreciation applies automatically unless the taxpayer elects out (an irrevocable election by class of property within recovery period). Ordering: §179 expensing first (subject to §179 limits), then bonus depreciation, then standard MACRS on remaining basis. Substantial planning interaction with §263A capitalisation rules and the §168 alternative depreciation system (ADS) for tax-exempt-use property.

How do listed-property and luxury-vehicle limits work?

Listed property under IRC §280F includes passenger automobiles, certain entertainment-and-recreation property, and certain computers (for years before 2018). The principal practical impact: passenger-automobile depreciation is capped at low absolute amounts regardless of asset cost. 2025 luxury-auto §280F caps for vehicles placed in service: First year USD 12,400 (USD 20,400 with bonus depreciation); Second year USD 19,800; Third year USD 11,900; Fourth and subsequent years USD 7,160 — until full cost recovery. SUV separate exception under §179 permits up to USD 30,500 §179 expensing on heavy SUVs (gross vehicle weight 6,001-14,000 lbs). Heavy-trucks-and-vans rules separately permit substantial first-year deduction. The combined effect: high-cost luxury vehicles produce material year-by-year tax-deferral spread; heavy SUVs and trucks produce substantial first-year deduction. Personal-use percentage reduces the deduction proportionately; >50 percent business use required for §168(k) bonus depreciation availability. The recent post-2018 IRS practice has tightened business-use-substantiation requirements for vehicle deductions, particularly for luxury and high-cost categories.

How do other major jurisdictions handle accelerated depreciation?

Most major economies offer some form of accelerated-depreciation or first-year-expensing incentive, with material design variation. UK: Annual Investment Allowance (AIA) at GBP 1 million per group per year — 100 percent first-year expensing on qualifying plant-and-machinery up to the AIA limit. Full Expensing under post-2023 reform — 100 percent first-year expensing on qualifying main-pool plant-and-machinery (post-March 2023; replaces the prior super-deduction). 50 percent first-year allowance for qualifying special-rate-pool assets. AIA + Full Expensing combined produce one of the most generous first-year-expensing frameworks in the OECD. Australia: Instant Asset Write-Off (IAWO) — post-2022 reform reduced the threshold materially from temporary COVID-era full expensing to AUD 20,000 per asset for SMEs (turnover under AUD 10 million) for tax year 2024-25. Backing Business Investment temporary measures expired post-2022. Germany: degressive Abschreibung (declining-balance) restored temporarily 2020-2022 at 25 percent (increased from 20 percent base); subsequent reform extended through 2024-25 with annual review. Forschungszulage R&D framework operates separately. Italy: 4.0 Hyper Depreciation (200 percent enhanced deduction on qualifying Industria 4.0 assets) — substantially restructured under post-2024 budget law. France: amortissement dégressif optional for qualifying assets; super-amortissement temporary for SMEs in defined sectors. Canada: Accelerated Investment Incentive — first-year deduction at 1.5 times the regular CCA rate for property acquired after 20 November 2018 through 2023; phasedown 2024-2027. Japan: special depreciation regimes under National Tax Special Measures Law for specified asset categories with material rate variation. Singapore: 100 percent first-year expensing on plant-and-machinery up to SGD 30,000 per asset (post-2020 reform).