A taxpayer who has held Qualified Small Business Stock for only 6 months can defer gain by rolling sale proceeds into new QSBS within 60 days, postponing the tax rather than eliminating it.
How it works
Sale proceeds minus original basis gives the realized gain. If replacement QSBS is bought within 60 days, the gain is deferred up to the amount reinvested, and the deferred amount reduces the basis in the new shares.
What this does not include
This does not include the separate Section 1202 exclusion available once QSBS is held 5 years, state tax treatment, or the per-issuer gain caps that apply to QSBS more broadly.
How to use this calculator
- Enter sale proceeds, original basis, replacement stock cost, and days since the sale.
Frequently asked questions
How is this different from the QSBS exclusion?
The Section 1202 exclusion permanently excludes gain after a 5-year hold; the Section 1045 rollover instead defers gain after just a 6-month hold, by reinvesting in new QSBS.
What happens if I miss the 60-day window?
The rollover doesn’t apply, and the full realized gain is recognized (taxed) in the year of sale.
Who can use a Section 1045 rollover?
Only non-corporate taxpayers — individuals, trusts, and estates — not corporations.
