Section 1045 Rollover: Preserving QSBS Eligibility Before 5 Years

You acquired QSBS from Company A in March 2024. The company was acquired for cash in January 2026, 22 months after your acquisition. You want the §1202 exclusion, but you are 38 months short of the 5-year hold. Section 1045 provides a way out: roll the proceeds into new QSBS within 60 days and preserve the holding period. Your 22 months of Company A ownership tacks onto the new QSBS. You need 38 more months of the new QSBS to reach the 5-year total.

IRC §1045 is the companion rule to §1202. It permits taxpayers to defer gain from the sale of QSBS if the proceeds are reinvested in new QSBS within 60 days. The rollover preserves the QSBS character and the tacking of the holding period, effectively allowing a mid-hold liquidity event without blowing the eventual exclusion.

This guide walks through the §1045 mechanics, the practical timeline, the reinvestment requirements, and the common traps.

The core mechanics

Under §1045(a), a non-corporate taxpayer can elect to defer gain from the sale of QSBS held more than 6 months if:

The taxpayer reinvests the sale proceeds (up to the amount of gain) in new QSBS within 60 days of the sale date
The taxpayer makes a timely election on the tax return

The gain is deferred, not eliminated. It becomes gain on the new QSBS when that stock is eventually sold.

Holding period tacks

The holding period of the new QSBS tacks onto the holding period of the old QSBS for §1202 purposes. Continuing the example: 22 months of Company A + 38 months of Company B = 60 months, satisfying the 5-year hold.

Basis carryover

Your basis in the new QSBS is reduced by the deferred gain. If you paid $1M for Company A shares, sold for $5M, and reinvested the full $5M, your basis in the new shares is $1M (original basis), not $5M.

On eventual sale of the new QSBS for $10M, your gain is $9M ($10M sale minus $1M basis). Under §1202, you apply the exclusion to this full gain if the 5-year hold is met.

The reinvestment must be in new QSBS

The replacement stock must itself be QSBS: issued by a qualified small business at original issuance, meeting the $50M gross-assets test, in a qualified trade or business. Buying shares of an already-mature public company does not qualify.

Typically this means investing in a new Series Seed or Series A company that qualifies as a QSBS issuer.

The 60-day window

The 60-day clock starts on the date of sale. The proceeds must be used to purchase new QSBS by day 60.

What counts as the sale date

Cash sale: the closing date of the sale
Stock-for-stock exchange: if part of a §368 reorganization, may be treated as no sale; else the exchange date
Tender offer participation: the settlement date

Why 60 days is tight

Finding a QSBS-eligible replacement investment, completing due diligence, and closing a purchase in 60 days is aggressive. Experienced investors pre-arrange replacement investments before the triggering sale.

Extensions

The 60-day window is hard. No extensions granted for typical circumstances. Federally declared disaster or certain other circumstances may extend, but these are rare and fact-specific.

What qualifies as reinvestment

Direct stock purchase at original issuance

Buy shares directly from a QSBS-eligible issuer. Most commonly participation in a priced round or a purchase from the company.

Conversion of a convertible instrument into QSBS

A SAFE or convertible note that was purchased before the §1045 trigger and converts into QSBS stock within the 60-day window can count, if structured correctly.

Purchase through a fund

Investment in a venture fund that is structured to pass through QSBS character to limited partners can count. Most traditional VC funds do not facilitate §1045 rollovers, but specialty “QSBS rollover funds” exist for this purpose.

Purchase via secondary transaction

Generally does not qualify. §1045 requires acquisition of stock at original issuance, not secondary market purchase.

Practical timeline

Example: QSBS sale closes January 15, 2026. 60-day deadline: March 16, 2026.

Day-by-day:

Day 1 (January 15): sale closes, proceeds wire in
Days 2-20: identify potential QSBS replacement investments
Days 20-40: diligence and term-sheet negotiation
Days 40-55: close on new investment
Days 55-60: complete wire and share issuance
Day 60 (March 16): last allowed close date

Realistic replacement investments: participation in an upcoming priced round at a different company, purchase of a new company’s Series Seed shares, or investment in a QSBS-eligible rollover fund.

How to make the election

Tax return disclosure

The §1045 election is made by reporting the rollover on your tax return for the year of the sale. Specifically:

Form 8949: show the sale of the original QSBS with appropriate code
Schedule D: summarize the gain subject to §1045 deferral
Attach a statement identifying the replacement stock, purchase date, and purchase price

Documentation to keep

Purchase agreement for the original QSBS
Sale closing documents
Purchase agreement and share certificate for the replacement QSBS
Cash flow records showing proceeds flowed to the replacement investment
Gross-assets certification from the replacement company (at the time of your purchase)
§1202 attestation for the replacement company if available

Deferral election is binding

Once elected, the rollover is final. You cannot unwind a §1045 election later. Make sure the replacement QSBS is a genuine investment you want to hold.

Interaction with §1202 at the eventual sale

When you eventually sell the replacement QSBS, the §1202 exclusion applies to the combined holding period and the combined gain (reduced basis from the rollover).

Combined holding period

Original holding + replacement holding = combined. Meeting the 5-year total across both investments is what matters.

Gain calculation

Gain on the replacement QSBS uses the carryover basis from the original QSBS (adjusted for the original gain).

$10M cap and 10x-basis

The per-taxpayer cap applies based on the basis as adjusted for the rollover. Rollover does not give you a new $10M cap.

Common traps

Missing the 60-day window

The most common trap. Replacement investments are harder to source than expected. Many taxpayers planning to use §1045 end up missing the window.

Rollover into a non-QSBS company

The replacement must itself be QSBS. Due diligence on the replacement company’s QSBS eligibility is essential. A replacement that turns out not to be QSBS blows both the rollover and the original exclusion.

Partial rollover

If you roll only part of the proceeds, only the rolled portion defers. The remainder is taxable as current gain. Partial rollovers add complexity and usually signal that the taxpayer should not have attempted the rollover.

Rollover fund without QSBS compliance

Some “QSBS rollover funds” may not consistently deliver QSBS investments. Verify the fund’s structure, underlying investments, and ability to pass through QSBS character.

Failure to make the election on time

The §1045 election must be made on a timely filed return (including extensions) for the year of the triggering sale. Miss the filing deadline with the election and the rollover is lost.

When §1045 makes sense

You hold QSBS and a forced sale occurs before 5 years

An acquisition, tender offer, or other involuntary sale inside the 5-year window. §1045 preserves the exclusion trajectory.

You want to diversify out of a concentrated QSBS position

§1045 lets you redeploy into a different QSBS company without triggering current tax. Useful for founders rotating capital into new ventures while maintaining the exclusion benefit.

You have access to high-quality replacement QSBS

The rollover only makes sense if the replacement investment is desirable on its own merits. Rolling into a weaker company to preserve tax character is usually bad investment strategy.

When §1045 doesn’t make sense

You don’t expect to hold the replacement to 5 years

If you plan to sell the replacement before 5 years total, the rollover just defers gain without producing the §1202 exclusion. Pay the tax now and move on.

Your gain is already excluded

If your exclusion cap ($10M or 10x basis) is already met, rolling over additional gain does not add benefit. Current recognition at LTCG rates may be better.

The replacement QSBS is speculative

Tax-driven reinvestment in weaker replacements creates business risk. §1045 should follow investment logic, not the other way around.

Frequently asked

Can I roll into multiple replacement companies?

Yes. §1045 permits rollover into multiple replacement QSBS investments as long as the aggregate purchase cost covers the gain.

Does a secondary market purchase qualify as replacement?

Generally no. Replacement QSBS must be acquired at original issuance.

What if the replacement company fails QSBS tests later?

QSBS status is tested at issuance and throughout your hold. A later failure can disqualify the replacement, but the IRS interpretation varies by fact pattern. Consult counsel.

Does §1045 apply to gain held by an S-corp or partnership?

§1045 is available to shareholders of S-corps and partners in partnerships that hold QSBS, with pass-through mechanics applying.

Does the 60 days include weekends?

Yes. 60 calendar days, including weekends and holidays.

Can I extend my filing to use more time for the rollover?

Extending your tax return does not extend the 60-day window. The window is measured from the sale date, not from the filing deadline.

Next step

If you hold QSBS and anticipate a sale inside the 5-year window, start identifying potential replacement investments now. Budget 30-60 days of lead time before any expected sale. Work with a tax advisor to pre-structure the §1045 election and reserve legal capacity for closing the replacement in 60 days. If a forced sale occurs without advance planning, prioritize speed over perfect diligence on the replacement investment; missing the 60-day window costs the entire exclusion.