Glossary term
Adjusted Basis
Adjusted basis is an asset's original tax basis after increases and decreases such as improvements, depreciation, returns of capital, or casualty adjustments.
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What Is Adjusted Basis?
Adjusted basis is an asset's original tax basis after required increases and decreases. It is one of the key numbers used to calculate taxable gain or loss when property is sold, exchanged, gifted, depreciated, or otherwise disposed of.
Basis often starts with cost, but it rarely stays untouched forever. Capital improvements, depreciation, casualty losses, returns of capital, certain assessments, and other tax adjustments can change the basis over time.
Key Takeaways
- Adjusted basis starts with original basis and then applies tax adjustments.
- It is used to calculate gain, loss, depreciation, and other tax consequences.
- Improvements may increase basis; depreciation and some recoveries may reduce it.
- Real estate, business assets, inherited assets, gifted assets, and investments can all have basis issues.
- Poor basis records can create tax surprises years later.
Basic Formula
At a high level, adjusted basis works like this:
Original basis is usually the starting tax basis, often cost for purchased property. Increases to basis may include capital improvements or certain acquisition-related costs. Decreases to basis may include depreciation, casualty-loss deductions, returns of capital, or recoveries that tax rules require the owner to subtract.
If a rental property was bought for $300,000, later received $40,000 of capital improvements, and accumulated $60,000 of depreciation, its adjusted basis may be $280,000 before considering other adjustments.
What Can Increase or Decrease Basis?
May increase basis | May decrease basis |
|---|---|
Capital improvements. | Depreciation deductions. |
Certain legal or title costs. | Casualty-loss deductions. |
Assessments for local improvements. | Returns of capital. |
Some acquisition or construction costs. | Insurance reimbursements or other recoveries. |
How It Changes the Tax Result
Taxable gain is generally measured by comparing amount realized with adjusted basis. A lower adjusted basis can create a larger taxable gain. A higher adjusted basis can reduce gain or increase loss, depending on the asset and tax rules.
Adjusted basis is especially important for rental real estate, business equipment, inherited or gifted property, stock with reinvested dividends, partnership interests, and property that has been improved over many years.
Where Basis Records Break Down
Basis problems often appear long after the original purchase. A property owner may remember the purchase price but lose track of improvements and depreciation. An investor may reinvest dividends for years and later forget that those reinvestments may affect basis. A business owner may depreciate equipment and then be surprised when the adjusted basis is much lower than the original cost.
Inherited and gifted property can add another layer because the starting basis may depend on transfer rules, date-of-death value, carryover basis, or other facts. The adjusted-basis question begins only after the correct starting basis is identified.
Recordkeeping
Keep closing statements, improvement invoices, depreciation schedules, reinvestment records, corporate action notices, and tax returns that support basis adjustments. Brokerage statements are helpful, but they may not capture every tax adjustment.
For real estate, separate repairs from capital improvements. Repairs may be currently deductible in some contexts, while improvements may affect basis. For investment accounts, preserve records through account transfers because basis data can be lost or incomplete when assets move between custodians.
The Bottom Line
Adjusted basis is the tax basis of property after increases and decreases. It is a quiet number until a sale, exchange, depreciation calculation, or transfer makes it central to the tax result.