Adjusted Basis: The Number That Determines Your Exit Tax

Basis is the number your exit is measured from

Ask most owners what they will owe when they sell, and the answer starts with the sale price. The statute starts somewhere else. Gain is the amount realized minus the adjusted basis (§1001(a)); the basis used for that purpose is your cost basis (§1012) as adjusted over the period you held it (§1011, §1016). So the figure your entire exit is measured from is not the price you paid and not the price you get. It is a running number that has been moving every year you owned the property.

That is why this is the first page in the Wealth & Exit domain and the parent of the ones that follow. Recapture is measured against the depreciation that lowered your basis. Capital gain is measured from your basis. A 1031 exchange carries your basis into the next property. Get basis right and the rest of the domain is arithmetic. Get it wrong and every downstream calculation inherits the error, usually in the direction of a larger bill than you planned for.

The mental model worth holding is a ledger that follows the property from the day you acquire it to the day you dispose of it: a starting figure, adjusted up and down along the way, landing at exactly the number your exit is measured from.

This is educational information about how basis works, not individualized tax advice. Your actual basis depends on your facts and your records, and should be confirmed with your own qualified tax professional. Where something below is our read rather than black-letter rule, it is labelled.

Where the ledger starts: cost, plus the closing costs that ride along

Basis begins as what the property cost you, and that is usually more than the contract price. Under §1012 basis is cost, and for real property certain acquisition costs are capitalized into basis along with the purchase price. Note certain: not every line on your settlement statement belongs there.

Costs of acquiring the asset are generally added — title and abstract fees, legal and recording fees, surveys, transfer taxes, owner's title insurance, and any seller obligations you agreed to pay. Costs of getting the loan generally are not — origination fees and points, the lender's appraisal, credit-report and underwriting fees. Those follow their own rules, and points on a rental are generally amortized over the loan term rather than added to basis. Prepaid items such as casualty insurance and property-tax proration are neither: they are expenses of operating, not costs of acquiring. IRS Publication 551 carries the working list, and your tax professional applies it to your actual settlement statement.

The practical point is that your starting basis is usually higher than the purchase contract — and this is the cheapest basis you will ever add, and the easiest to lose. Nobody reconstructs a settlement statement from eight years ago with enthusiasm. Capture it in the month you close.

What moves it up: improvements, and the line the regulations draw

Money spent on work that is properly chargeable to capital account increases basis (§1016(a)(1)). Routine repairs and maintenance do not — they are current deductions.

Where that line falls is not a matter of feel. The tangible property regulations set it out: an expenditure must be capitalized if it is a betterment of the property, a restoration of it, or an adaptation to a new or different use (Reg. §1.263(a)-3). Replacing a roof, adding a bathroom, replacing an HVAC system, converting a garage into a bunk room — those sit on the capital side. Repainting between guests, patching drywall, servicing the furnace, replacing a broken slat — those do not. The regulations also provide safe harbours that let smaller amounts be expensed even when they might otherwise be capitalized, including a de minimis election and a routine-maintenance safe harbour.

Short-term rentals put unusual pressure on this line, and that is the STR-specific reason the section exists. A property turning over fifty or eighty times a year generates a constant stream of spending that looks like maintenance and occasionally is not: the third mattress replacement is maintenance, the deck rebuild is a betterment, the hot tub is a new asset entirely. High turnover also produces high volume, which is precisely the condition under which classification decisions get made quickly and recorded badly. Every misclassification moves basis, in one direction or the other, and the error is not discovered until the exit.

What moves it down: depreciation, allowed or allowable

The other force is depreciation. Because the building and its components are depreciated over the hold, that depreciation reduces basis (§1016(a)(2)) — and the statutory language is the part worth memorising. Basis is reduced by depreciation allowed or allowable, and not less than the amount allowable.

Read that plainly: the reduction happens whether or not you claimed the deduction. Skipping depreciation does not preserve a higher basis. It gives up the deduction and reduces the basis anyway, which is the worst available outcome — you pay tax during the hold and at the exit on the same dollars. An owner who discovers years of unclaimed depreciation generally has a correction procedure available rather than a lost cause, and that is a conversation to have with a professional promptly rather than at closing.

There is one interaction genuinely worth raising with your own advisor rather than settling from a web page. Many STRs have owner personal-use days, and where personal use limits deductions the amount actually allowable for a year is not simply the full schedule figure. How the allowed-or-allowable rule applies in that situation is fact-specific, and it is exactly the kind of question where the general rule and your return can diverge. Raise it; do not assume either answer.

An STR is not one basis ledger — it is several

This is where short-term rentals stop resembling the textbook example, and it is the part most basis explanations skip.

A generic rental has, roughly, two components: land, which is never depreciated, and a building depreciated over its recovery period. A cost-segregated, furnished short-term rental has considerably more. A cost-segregation study reallocates the purchase price across asset classes — personal property such as appliances, cabinetry, carpeting and specialty electrical; land improvements such as driveways, fencing, pools and landscaping; and the building itself. Each class carries its own basis and its own recovery period, and each is depreciated on its own schedule.

Then add the furnishings. STRs are let furnished, so the owner buys beds, sofas, televisions, linens, cookware, a hot tub, sometimes a golf cart. Those are separate depreciable assets with their own basis, frequently written off quickly through bonus depreciation or a §179 election.

Two consequences follow, and both land at the exit. First, "adjusted basis" is really the sum of several ledgers, some of which have been driven to nearly zero while the land allocation has not moved at all. Second — and this is the one that surprises people — the character of your gain at sale is decided by which ledger the gain sits against. Basis written off against personal property generally comes back as ordinary §1245 recapture; basis written off against the building generally produces unrecaptured §1250 gain taxed at its own rate. A cost segregation study does not only accelerate deductions. It changes the shape of the tax bill waiting at the exit, because it changes which ledgers absorbed the depreciation. How those pieces are characterised is the recapture guide's subject; the reason it can differ is basis, which is this page's.

The two starting points that are not cost

Most of the time basis starts at cost. Two common STR paths do not, and both are easy to get wrong.

A property you already owned, converted to a rental. Buying a second home or a primary residence and later turning it into a short-term rental is one of the most common ways into this business. On conversion, the basis used for depreciation is generally the lesser of your adjusted basis or the property's fair market value at the date of conversion. That lesser-of rule is a trap in a rising market and a bigger one in a falling market, and the basis used to compute a later loss can differ from the basis used to compute a later gain. If your STR started life as somewhere you lived, this is a documented conversion-date valuation you want on file, not a number to estimate later.

Property that arrived carrying someone else's basis. Acquire through a like-kind exchange and your old adjusted basis generally carries into the replacement property (§1031(d)). Receive by gift and you generally take the donor's carryover basis (§1015). Inherit, and basis is generally stepped up to date-of-death value (§1014). Each of those has its own page in this domain; they appear here so you can see that basis is the common thread through every way a property changes hands.

Why basis makes deferral "deferral"

The carryover rule is also the cleanest explanation of what a 1031 exchange actually does. Roll into a replacement property and the gain is not erased. It moves, and the vehicle it moves in is the low basis you carry forward. Your new property starts life with a basis reduced by all the gain you deferred, which means a smaller depreciation deduction going forward and a larger gain waiting at the next sale, unless that one is exchanged too.

That is the mechanical reason "defer" is not "avoid," and it is worth saying in basis terms rather than as a slogan: deferral is the practice of pushing gain forward inside a shrinking basis. For the typical individual investor the chain generally ends in one of two ways — a taxable disposition, which settles it, or, under current law, a reset at death through §1014 for whoever inherits. Treat those as the common paths rather than an exhaustive list: entity ownership, partnership interests and less usual dispositions each carry their own analysis, and which applies to you is a question for your own tax professional. Either way, the point holds — the deferral is not free optionality. It is a growing embedded liability, recorded as a low number on a ledger.

Tracked during the hold, or reconstructed at closing

Everything above depends on records that exist. Your adjusted basis is only right if you tracked it: acquisition costs captured at purchase, every capital improvement recorded and distinguished from repairs, depreciation taken correctly and consistently across every asset class, the cost segregation study retained, disposed components removed rather than left on the schedule.

The owner who can produce a clean basis schedule at closing has options — they can model an exchange against a real number, decide between selling and refinancing on facts, and answer a buyer's diligence without guessing. The owner reconstructing a decade of capital work from bank statements and memory tends to accept whatever number is available under time pressure, which is reliably not the favourable one.

Basis is built during the hold. It is a bookkeeping discipline, not an exit task, and the week you list the property is far too late to start.