What Is Bonus Depreciation for a Small Business?
Depreciation is normally a slow-and-steady process, spreading an asset’s cost across many years. Bonus depreciation is the exception built into that system — a way to front-load a much larger chunk of the deduction into the first year an asset is used.
The short answer
Bonus depreciation is an additional first-year depreciation deduction available for qualifying business assets, on top of or instead of standard depreciation schedules. Unlike the Section 179 election, it generally applies automatically by default rather than requiring an active choice for each asset, and it typically isn’t limited by how much taxable business income exists in a given year.
How it differs from Section 179 in practice
Both tools accelerate depreciation, but the mechanics diverge in a few practical ways.
- Election versus default. Section 179 must generally be elected asset by asset, while bonus depreciation typically applies automatically unless a business affirmatively opts out.
- Income limitation. Section 179 is generally capped by business taxable income for the year; bonus depreciation typically isn’t restricted that way, which means it can contribute to or deepen a loss for the year.
- Ordering and interaction. Businesses often apply Section 179 first, up to its own limits, and then apply bonus depreciation to remaining eligible cost, though the exact sequencing can depend on the specific assets and elections involved.
The percentage isn’t fixed
One of the more important things to understand about bonus depreciation is that the percentage of an asset’s cost eligible for this immediate deduction has changed multiple times over the years and is set by the government, subject to further change. Rather than stating a specific percentage that could be outdated by the time this is read, the more durable point is the concept itself: a portion, sometimes all, of a qualifying asset’s cost can be deducted immediately rather than spread across the asset’s normal depreciation schedule, and that portion is a policy lever that gets adjusted periodically.
Why it can create a business loss
Because bonus depreciation isn’t limited by taxable income the way Section 179 is, a business can end up reporting a loss for the year specifically because of a large bonus depreciation deduction, even if the business is otherwise healthy and cash-flow positive. That loss can sometimes be used to offset other income or carried to different tax years as a net operating loss, subject to its own separate set of rules, and it can also interact with other pass-through considerations, like the qualified business income deduction, depending on how the business is structured.
Where this shows up for real estate and rentals
Certain assets connected to rental or business real estate can qualify for bonus depreciation treatment, which is part of why questions about how a tenant improvement allowance is capitalized and recovered sometimes intersect with this topic — some categories of shorter-lived building components can potentially qualify, while the structure of the building itself generally follows a much longer depreciation schedule regardless.
What to weigh
Bonus depreciation is a powerful timing tool, but timing is really all it changes — the total amount of depreciation available over an asset’s life is generally the same either way, just recognized sooner rather than later. Front-loading that much deduction into a single year makes the most sense when it lines up with a business’s broader income picture and plans, which is worth mapping out with a tax professional rather than assuming faster is automatically better.