Qualified Small Business Stock, or QSBS, continues to be one of the most valuable tax incentives for company founders and investors, but recent federal and state changes have made it even more essential to plan carefully and maximize your potential savings. For taxpayers who qualify, the Qualified Small Business Stock exclusion can significantly lower the tax owed when shares are sold. Before counting on the benefit, it is important to understand what qualifies, how federal and state rules may differ, and where you can find planning opportunities.
What is Qualified Small Business Stock?
Qualified Small Business Stock, also known as Section 1202 stock, are shares of a domestic C-Corporation that meet specific requirements under Internal Revenue Code Section 1202. The rule was created to encourage investment in certain small businesses by allowing eligible shareholders to exclude a portion, or possibly all, of the gain from federal income tax when they sell qualifying stock after holding it for more than five years.
The amount of gain that can be excluded depends mostly on when you received the stock. If QSBS was acquired after Sept. 27, 2010, the federal exclusion may be as high as 100%.
QSBS can benefit founders, early-stage investors, employees who receive qualifying stock as compensation, search funders, and family office investors, but only if the stock and company meet the Section 1202 requirements.
Requirements to qualify
To qualify, the stock generally must be originally issued by a domestic C-Corporation and acquired directly by the shareholder in exchange for money, property, or services; it can’t be purchased from another shareholder. The shareholder also must be an eligible noncorporate taxpayer, such as an individual, trust, estate, partnership, or other pass-through investor, and must hold the QSBS for more than five years before selling it to qualify for the federal gain exclusion.
During that holding period, the company must meet the active business requirements, meaning at least 80% of its assets must be used in the active conduct of a qualified trade or business. Certain service-based businesses, including health, law, accounting, engineering, and financial services, are excluded from the QSBS rules.
Recent federal changes to Section 1202
In 2025, the One Big Beautiful Bill Act (OBBBA) made major updates to the Qualified Small Business Stock rules that affect small business owners and investors looking to reduce their capital gains taxes. The new rules apply to stock acquired on or after July 4, 2025, with any obtained before then still following the old rules.
The OBBBA amendment added partial tax breaks available before the five-year threshold:
- If you hold QSBS more than three years, you get a 50% gain exclusion.
- If you hold QSBS more than four years, you get a 75% gain exclusion.
- If you hold QSBS five years or more, you get a 100% gain exclusion (unchanged).
If you use the 50% or 75% QSBS exclusion, the remaining gain is taxed at 28%, but it won’t trigger the alternative minimum tax (AMT). The OBBBA rules didn’t change how QSBS bought before Sept. 27, 2010, is treated. For gains under the new three- or four-year OBBBA holding periods, any non-excluded portion is also taxed at 28% and still avoids the AMT.
For all QSBS issued on or after July 4, 2025, the lifetime gain exclusion limit has increased from $10 million to $15 million per shareholder. Also, the “aggregate gross asset” test for businesses issuing QSBS has expanded. Before the change, a company could have up to $50 million in gross assets. Under OBBBA, that maximum limit is now up to $75 million in gross assets at the time of stock issuance.
These changes matter because many businesses and investors that previously may not have qualified or were limited by previous thresholds may now have more planning opportunities.
State changes to QSBS treatment
Many states generally follow the federal QSBS rules, so if the gain is excluded on the federal return, it may also be excluded from state income tax in those states. However, state treatment is not always as straightforward. States do not automatically follow every federal tax change, and some have chosen to decouple from specific provisions. That means a gain that is excluded for federal tax purposes may still be taxable at the state level, depending on where the taxpayer lives or files.
Illinois QSBS treatment
Illinois is one example. Under Senate Bill 3019, signed into law on June 16, 2026, Illinois will decouple from IRC Section 1202 for tax years ending on or after Dec. 31, 2026. That means individuals, trusts, estates, and partnerships that exclude gains from the sale of certain Qualified Small Business Stock on their federal return will need to add the excluded gains back when calculating Illinois taxable income.
For Illinois founders, investors and family offices, this makes state tax planning an important part of the QSBS conversation. The federal exclusion may still provide a benefit, but it may not eliminate the full tax impact of a sale. Before a transaction, taxpayers should understand both the federal rules and the state treatment that may apply.
Other state variations
Illinois is not the only state where QSBS treatment is getting a closer look. Some states, including California, Pennsylvania, Alabama, and Mississippi, generally do not follow the federal Section 1202 exclusion, which means QSBS gain that is excluded federally may still be taxable for state purposes. Hawaii partially conforms, allowing the partial capital gains exclusion of 50%. Those state differences can have a real impact on how investors keep after a sale.
Other states are taking a more taxpayer-friendly approach. In many states, if the gain is excluded on the federal return, it may also be excluded for state income tax purposes. For instance, New Jersey moved in the opposite direction of Illinois. After previously being treated as a nonconforming state, New Jersey now provides its own exclusion similar to the federal QSBS exclusion for tax years beginning on or after Jan. 1, 2026.
States without an individual income tax may create a different result because there may not be state-level tax on the QSBS gain in the first place. But if you live in one state, move to another, or have ties to more than one state when you sell, details like residency, sourcing, and timing can still matter.
The main takeaway is that QSBS planning should not stop at the federal level. State rules can preserve the federal benefit, reduce it, or eliminate much of the expected savings at the state level.
Planning opportunities for business owners and investors
The recent QSBS changes create new opportunities for business owners, startup founders, and investors to revisit their planning before a transaction. For companies, this could mean looking at whether a C-Corporation structure makes sense, making sure the business meets the active business requirements, and gathering documentation that shows their eligibility early. For investors, it is important to review stock issuance records, holding periods, and whether the stock was received directly from the company.
QSBS can also play a role in overall wealth, trust, and estate planning. Because the potential tax benefit can be significant, founders and investors should think about how QSBS fits into future fundraising, gifting, estate plans, or a business exit. The earlier this happens, the more flexibility there may be to coordinate federal and state tax treatment and avoid surprises when it is time to sell. Working with an advisor can help you align your strategies.
Common QSBS mistakes to avoid
QSBS can offer a tax benefit, but the rules can be confusing. A few common mistakes can prevent your stock from qualifying altogether:
- Assuming all startup stock qualifies: Not every early-stage company or startup investment meets the Qualified Small Business Stock requirements. The company must be a qualifying C-Corporation, meet the gross asset and active business rules, and issue the stock directly to the shareholder.
- Not keeping the right records: Stock issuance documents, purchase agreements, capitalization tables, and other support can help show when the stock was issued, how it was acquired, and why it qualifies. It is easier to gather these records early than to find and organize them right before a sale.
- Overlooking state tax rules: A federal QSBS exclusion does not always mean the gain will be excluded at the state level. State conformity rules, residency, and timing can all affect the final tax result.
- Waiting until a sale to plan: QSBS planning works best before a transaction is already happening. Reviewing all the factors early can help you keep the benefit.
Because the QSBS rules are detailed and state treatment can be different, it is worth reviewing your stock, structure, and other factors before a sale. An advisor can help confirm eligibility, estimate the potential tax benefit, and find planning opportunities that may help you preserve more of the gain.