QSBS vs Section 1045 Rollover: Which Break Fits Your Exit

QSBS vs 1045: The Short Answer

The choice between the QSBS exclusion and a Section 1045 rollover comes down to your timing and your plans. Section 1202 erases the gain entirely once your stock clears five years of holding.

Section 1045 instead defers the gain into new qualified small business stock when you exit early.

Sellers past the five-year mark should usually take the exclusion and close the chapter. Sellers exiting at year two or three face a genuine decision with real dollars attached.

A rollover keeps the tax bill open but preserves full buying power for the next opportunity.

What the QSBS Exclusion Removes

Qualified small business stock is C corporation stock bought directly from the company at original issuance. The company must run an active qualified trade or business throughout your holding period.

Gross assets must stay at or under $50 million at issue, or $75 million for post-July 2025 stock.

Hold qualifying shares for five years and the exclusion wipes out the entire gain on the sale. Per issuer, the cap is the larger of a $10 million ceiling or ten times your basis.

Both numbers apply separately to each company whose stock you own. A founder investing $300,000 and exiting at $12 million can shield the whole gain under ten-times-basis rules.

Our guide to the QSBS exclusion rules covers the qualifying tests in careful detail for new investors. The phase-in rules for newer issuances appear in the tiered exclusion breakdown on this site.

How the Section 1045 Rollover Works

Section 1045, defined in the rollover rules of the tax code, serves one specific situation. You sell qualifying stock before the five-year mark and want to reinvest without losing the runway you earned.

You then have 60 days from the sale to buy replacement stock from a different qualifying C corporation.

Blow that deadline and the deferred gain turns taxable right away, in the sale year. Your replacement shares start life with their basis lowered by exactly the amount you rolled over.

The old stock's holding period tacks onto the replacement shares, a detail most sellers miss on the first try.

Sell after three years of holding and the replacement stock inherits that time toward its own exclusion clock. Two structural limits shape the rollover maneuver in practice, and both catch first-time sellers.

Only non-corporate taxpayers can roll gains, and the replacement purchase must at least match the deferred gain. Falling short on either count disqualifies the whole rollover attempt.

The replacement company does not need to match the old one in size or sector. Any qualifying C corporation works for the swap, in any industry that passes the tests.

That freedom lets sellers chase better opportunities while the deferral carries forward quietly.

The Tiered Exclusion Changes the Math

The sweeping One Big Beautiful Bill Act reshuffled the QSBS holding timeline, as our OBBBA changes guide explains. Shares issued from July 4, 2025 onward earn a partial exclusion even before the five-year mark arrives.

The ladder below shows the new phased structure against the old all-or-nothing exclusion cliff.

The tiers cut both ways for rollover planning, and the direction depends on your exit year. A seller at year three keeps half the gain taxable, which makes a 1045 roll more attractive than before. The summary of OBBBA provisions for investors covers the legislative details.

Two cap changes matter for large exits in particular, and both loosen the old limits. The per-issuer exclusion ceiling for post-July 2025 stock rose to $15 million from the earlier $10 million. The gross asset test loosened to $75 million as well, so bigger companies now fit inside the QSBS box.

Worked Example: A $2 Million Exit Two Ways

Picture stock bought for $400,000 that sells for $2.4 million at the three-year mark, producing a $2 million gain. Under the tiered rules, half of that gain escapes tax and $1 million remains taxable. At a 23.8 percent combined federal rate, the bill lands near $238,000 for the year.

The rollover path looks completely different on the same facts, and usually far more attractive. Roll the entire $2 million gain into replacement QSBS within 60 days and the sale year owes nothing.

That zero stands until the replacement stock eventually sells. Your original $400,000 of basis follows the deferral over to the new position automatically.

The new shares carry a reduced basis equal to old basis minus the deferred gain. Fresh cash invested alongside the rollover adds basis on top of that figure. The new shares also inherit the three-year clock through tacking, so two more years completes the run.

Now flip the timing and sell the same position at year five instead. The exclusion then takes the entire $2 million without any rollover mechanics being needed. The 1045 maneuver earns its keep only between six months and five years of holding.

Rolling Repeatedly and Stacking Exclusions

Nothing in the statute stops a seller from rolling gains more than once. Each rollover starts a new 60-day window with a new issuing company, and the tacked holding period keeps running. Venture investors who move between companies can string several exits together before recognizing a single dollar.

The exclusion cap is the brake on that chain, and it works at the issuer level. Each company gets its own cap measured against your basis in that particular stock. Rolling from company A into company B starts a fresh cap, and the old lot's unused room does not transfer.

Business owners weighing other deal structures should read the comparison of asset sale versus stock sale taxation. Plenty of other deferral tools exist beyond QSBS and 1045. Our deferral strategies for investors guide covers that full menu in one place.

Mistakes That Sink Both Strategies

The 60-day window is the most common rollover failure point in practice, without question. Deals fall through at the last minute, wire timing slips, and closing documents arrive late. The IRS grants no extensions for missed dates, so sophisticated sellers identify the replacement company before listing the first shares.

Qualification failures hurt even earlier in the timeline, before any window even opens. Stock bought on a secondary market from another shareholder is not original issuance and never qualifies. Companies in finance, hospitality, and professional services fail the active business test outright as well.

Basis tracking is the quiet killer on the exclusion side of the ledger. The ten-times-basis cap needs documented basis across every grant and purchase date. Founders who cannot reconstruct their history leave exclusion room on the table at the exit.

Corporate holders face a hard wall in both directions at once under these rules. Section 1045 is closed to corporations entirely, and partnerships hold QSBS at the partner level instead. Confirm your taxpayer type early, before you promise anyone a completely tax-free exit.

Choosing Between the Two Paths

Run the decision through three questions in order. First, how long have you held the stock, because the tacked clock decides how much runway remains. Second, do you actually want to reinvest, since the rollover only helps sellers staying in the game.

Third, how large is the gain against each issuer's exclusion cap on the books. Sellers at five years or beyond take the exclusion without ceremony. Sellers in the middle years who want continued startup exposure roll the gain forward instead of paying the tier.

Exit planning gets much fuller treatment in our business owner capital gains guide. The wider playbook of legal avoidance strategies pairs well with this particular decision.

A Compliance Checklist Before You Transact

Confirm the issuing company was a C corporation at issuance and stayed one through your holding period. Pull the original stock purchase agreement to prove original issuance on your specific shares. Check the gross asset test at the issue date against the correct threshold for your vintage.

Verify the active business test covered every year you held, not just the first one. Calculate the exclusion cap against your documented basis before assuming full coverage. Calendar the 60-day replacement window the moment you sign a sale agreement.

Primary sources live at the IRS small business pages and in the statute itself. Breaks this generous punish sloppy paperwork, so treat the documentation as the whole game.

State Tax and NIIT Notes on the Gain

The federal exclusion does not automatically extend to state income tax everywhere. Several states decouple from Section 1202 and tax the gain anyway, with California and New Jersey the classic examples. Confirm how your own state conforms before assuming the gain is fully sheltered.

States that do conform often still require a separate state-level exclusion calculation on the return. The paperwork burden is real but manageable. Budget for it in the exit plan rather than treating it as an afterthought at filing time.

The NIIT rarely matters for QSBS exits, because excluded gain never reaches net investment income. The taxable half of a tiered exit can still stack into MAGI and attract the 3.8 percent surtax. The NIIT mechanics guide explains how that surtax stacks on capital gains.

Timing Notes for the Sale Year

Coordinate the rollover decision with the rest of your tax picture before signing anything. A partial tier exit adds taxable gain to the sale year, which can push other income into higher brackets. Run the combined projection before choosing between the tier and the roll.

Estimated tax payments deserve a quick check as well. A large recognized gain can require a quarterly payment to avoid underpayment penalties. Set aside cash from the closing proceeds when the tier route leaves real tax due for the year.

The Rules That Decide Everything

Both strategies reward the same underlying discipline across the whole holding period. Original issuance stock, a qualifying C corporation, and clean records decide the final outcome. The exclusion erases the gain after five years while the rollover buys time to reach that line.

Used together, they let a patient investor move between qualifying companies for a full decade without recognizing a gain. Confirm the per-issuer cap before every transaction you sign. Calendar the 60-day window immediately, because this corner of the tax code lives entirely on dates.