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 tax code 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 basis comes before every other exit question. Recapture is measured against the depreciation that lowered your basis (Depreciation Recapture: Why Your Gain at Sale Isn't All Capital Gain). Capital gain is measured from your basis. A 1031 exchange carries your basis into the next property (The 1031 Exchange for Short-Term Rentals). Get basis right and the rest of the exit is arithmetic. Get it wrong and every later calculation inherits the error, usually in the direction of a larger bill than you planned for.

The easiest way to picture basis is as a ledger that follows the property from the day you acquire it to the day you dispose of it. It has a starting figure, it is adjusted up and down along the way, and it lands 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 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 added to basis along with the purchase price. Note certain: not every line on your settlement statement, the closing document that itemizes what was paid, 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 (interest paid up front to the lender), the lender's appraisal, credit-report and underwriting fees. Those follow their own rules, and points on a rental are generally amortized, meaning deducted gradually over the loan term, rather than added to basis. Prepaid items such as casualty insurance and the property-tax proration (the split of the year's property tax between buyer and seller at closing) 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: your starting basis is usually higher than the contract price. These costs are the cheapest addition to basis you will ever make, 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

Spending on improvements, which the statute describes as items "properly chargeable to capital account," increases basis (§1016(a)(1)). Routine repairs and maintenance do not; they are deducted currently instead.

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 harbors that let certain costs be deducted right away even when they might otherwise be capitalized, including a de minimis election for low-cost items and a routine-maintenance safe harbor for recurring upkeep. A safe harbor is a rule that gives you a set result if you meet its conditions.

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

What moves basis down is depreciation. The building and its components are depreciated over the time you hold the property, and that depreciation reduces basis (§1016(a)(2)). The statutory wording is the part worth memorizing: 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 (see Depreciation for Short-Term Rentals), and that is a conversation to have with a professional promptly rather than at closing.

One situation is genuinely worth raising with your own advisor rather than settling from a web page. Many STRs have days when the owner uses the property personally. Where personal use limits deductions, the amount actually allowable for a year is not simply the full figure from the depreciation schedule. 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, the number of years the tax rules set for writing it off. A cost-segregated, furnished short-term rental has considerably more. A cost-segregation study reallocates the purchase price across asset classes: items treated as personal property for tax purposes, 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 rented 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, both of which can move much of the deduction into the first year.

Two consequences follow, and both show up at the exit. First, "adjusted basis" is really the sum of several ledgers. Some of them 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 (what kind of gain it is, which decides how it is taxed) depends on which ledger the gain sits against. Basis written off against personal property generally comes back as §1245 recapture, taxed as ordinary income. 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 characterized is covered in Depreciation Recapture; the reason it can differ is basis.

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 (what it would sell for) 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, meaning the donor's basis carries over to you (§1015). Inherit, and basis is generally stepped up to the property's value at the date of death (§1014). Exchanges are covered in The 1031 Exchange for Short-Term Rentals and inheritance in What Happens to an STR's Tax Basis When You Die?; gift basis has rules of its own beyond this summary, so take a gifted property's basis to your tax professional. All three 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 forward, carried in the low basis you bring into the new property. 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 means pushing gain forward inside a basis that keeps shrinking. For the typical individual investor, a chain of exchanges generally ends in one of two ways — a taxable disposition, which settles it, or 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: deferral is not free flexibility. It is a deferred tax bill that keeps growing, built into the property and recorded as a low number on a ledger.

Tracked during the hold, or reconstructed at closing

Everything above depends on having the records. 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, and components you have disposed of removed from the depreciation schedule rather than left on it.

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 due-diligence questions 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 favorable one.

Basis is built during the hold. It is a bookkeeping discipline — the records The STR Bookkeeping Operating Manual sets up — not an exit task, and the week you list the property is far too late to start.