A late-stage acquirer offers your company a strategic partnership. Part of the deal includes a $5M secondary tender for the founders: cash off the table at the new round’s price. You said yes before you finished reading the slide.

Then you ask your CPA whether the proceeds are taxed at the 23.8% capital-gains rate or your 37% ordinary-income rate. They say it depends. The difference, on $5M of gain, is roughly $660,000.

Founder secondary sales (tender offers, fund-led secondaries, third-party buys) have become the standard pre-exit liquidity event, and among the most tax-misunderstood. Companies like Carta and Stripe have run them. The QSBS interactions are non-obvious, the compensatory-tender trap is real, and the $5M of “cash off the table” can land net of federal tax somewhere between $3.8M and $4.5M depending on how the deal is structured.

This guide walks through what a founder secondary actually is, the three tax outcomes possible, when QSBS survives the sale, and the structural questions to ask before saying yes.

The four flavors of founder secondary

“Secondary” gets used loosely. The four common structures have meaningfully different tax mechanics:

  • Company-sponsored tender offer. The company invites founders and early employees to sell a portion of their shares back to the company itself (or to designated buyers at a coordinated price). Common in late-stage rounds where investors want to give founders partial liquidity.
  • Third-party tender offer. An outside buyer (often a secondaries fund or family office) makes an open offer to buy shares from founders and employees at a fixed price. The company facilitates but isn’t the buyer.
  • Fund-led secondary in a primary round. A new investor (typically a growth-stage VC or PE fund) invests new capital into the company and buys existing shares from founders, both at the same per-share price. The “secondary portion” of the round goes to founders.
  • 1x buyer secondary. A single buyer, often an existing investor, purchases a chunk of founder stock outside any formal tender. Quieter, more negotiated, often clean.

The buyer side of each one is different. The founder-side tax treatment is similar in most cases, but with one important wrinkle.

The three tax questions every founder should ask

Before signing any secondary transaction, three questions determine the after-tax outcome:

1. Is the gain capital or ordinary income?

If you’ve held the stock more than one year, the default expectation is long-term capital gain at about 23.8% federal (20% LTCG + 3.8% NIIT). That expectation is usually right: it’s the answer in most third-party tender offers, fund-led secondaries, and 1x buyer secondaries done at fair market value.

The exception, and often the most expensive misunderstanding in this space, is the compensatory tender offer. If the company itself sponsors the tender and pays a price above the 409A FMV, the spread between FMV and the tender price can be treated as compensation. That portion is generally taxed at your ordinary income rate (up to 37% federal) plus payroll taxes, not as long-term capital gain.

A 409A is the periodic third-party valuation of a private company’s common stock. If your tender offer is being run at $40/share and the most recent 409A is $30/share, the IRS can characterize the $10/share spread as compensation paid to you in your capacity as an employee or service provider, not as proceeds from selling property. A premium over the 409A price feels like a win, and economically it is. But this treatment is prevailing tax practice rather than a bright-line statutory test, so the position the company takes on the premium, and how it reports it, matters.

On $5M of proceeds, the difference between LTCG treatment and ordinary-income treatment is roughly:

  • LTCG: $5M × 23.8% = about $1.19M federal tax
  • Ordinary income (top bracket): $5M × 37% + payroll taxes ≈ $1.85M+ federal

That’s a roughly $660K delta. On a $20M tender, it’s roughly $2.64M.

2. Does the §1202 QSBS exclusion apply?

If your stock qualifies as QSBS (issued by a domestic C-corp at original issuance, held for the requisite period under §1202), selling some of those shares in a secondary is generally a regular §1202 disposition event. You can claim the exclusion on the gain, subject to the per-taxpayer cap: the greater of $15M or 10× basis for post-OBBBA stock, $10M for pre-OBBBA.

Two important nuances:

  • The §1202 exclusion only applies to the capital gain portion of the proceeds. If part of the tender is classified as compensation (the trap above), that portion is not eligible for §1202. It’s ordinary income, not capital gain.
  • Selling some shares in a secondary doesn’t restart the clock on the rest of your shares. Each share lot has its own holding period. If you sell half your QSBS at year 3 (50% exclusion under OBBBA’s tiered structure for post-July-4-2025 stock), the other half continues its clock toward year 5 (100% exclusion).

3. Does the deal affect the QSBS status of other shareholders?

This is the question founders almost never ask, and often the most consequential one for the cap table.

If the company itself buys back stock, either directly or by funding the tender, that buyback is a “redemption” under §1202(c)(3). Significant redemptions within one year before or one year after a stock issuance can disqualify the issuance from QSBS treatment. “Significant” means the company purchased stock with an aggregate value exceeding 5% of the aggregate value of all the company’s stock, measured as of the beginning of that two-year window. (A separate, stricter rule covers redemptions from you or persons related to you within two years before or after your issuance; those are disregarded only if the company paid $10,000 or less or bought back 2% or less of the stock held by you and your related parties.)

Practical implication: a tender that involves the company redeeming $20M+ of stock can taint QSBS issuances made anywhere in the surrounding 24-month window. If you’re a founder considering a tender that the company will fund through a redemption mechanic, the diligence question isn’t just “what’s my tax?” It’s “does this kill QSBS for the rest of the cap table?”

Many company-sponsored tenders are structured to avoid this, either by routing the purchase through a non-affiliated buyer or by keeping the redemption below the significant-redemption threshold. Confirm the structure with the company’s tax counsel before signing.

When QSBS survives the secondary

For the founder’s own gain on the shares being sold, QSBS treatment generally survives a secondary sale, provided:

  • The shares qualified as QSBS at original issuance (C-corp, original issuance, ≤$50M gross assets pre-OBBBA or ≤$75M post-OBBBA, active business)
  • The founder has held the shares for the required period (5 years for full exclusion pre-OBBBA, or 3/4/5-year tiered exclusion for post-OBBBA stock)
  • The gain is taxed as capital gain (not ordinary income via the compensatory trap)
  • No transaction-specific QSBS disqualifier (working-capital limits, anti-churning rules, etc.) applies

For the buyer in a secondary, QSBS is typically lost. §1202 requires the stock to be acquired at “original issuance” from the company. A secondary buyer purchases existing shares from another shareholder, not at original issuance, so the secondary buyer’s shares are generally not QSBS. The exception: if the company facilitates a redemption-and-reissuance structure, the buyer can sometimes pick up QSBS on the newly issued shares. That’s rare and requires careful structuring.

For other shareholders on the cap table, the redemption-disqualification trap discussed above is the risk. If the company funds a significant buyback to facilitate the tender, surrounding QSBS issuances can lose QSBS status.

Worked examples: three scenarios on a $5M secondary

Assume in each scenario: a founder owns 1M shares of post-OBBBA QSBS issued in September 2025 at $0.001/share (basis about $1,000). The shares now trade at $50/share. The founder sells 100,000 shares ($5M) in a secondary at year 3. The numbers are illustrative; your facts will move them.

Scenario 1: Third-party tender at FMV, clean capital gain.

  • Proceeds: $5M
  • Basis: $100
  • Gain: about $5M, fully capital gain
  • §1202 treatment: post-OBBBA stock held 3 years → 50% exclusion at the federal level. Gain is “§1202 gain” under IRC §1(h)(7); non-excluded portion taxed at 28% + 3.8% NIIT = about 31.8%
  • Excluded: $2.5M
  • Taxable: $2.5M × about 31.8% = about $795K
  • Net after federal tax: about $4.21M (84.1% retention)

Scenario 2: Company-sponsored tender at $50/share when 409A FMV is $35/share.

  • Proceeds: $5M total ($3.5M at FMV, $1.5M premium)
  • The $1.5M premium is treated as compensation income, not capital gain
  • Capital gain portion: $3.5M − $100 basis ≈ $3.5M, §1202-eligible
  • 50% excluded under the post-OBBBA 3-year tier: $1.75M tax-free
  • Taxable §1202 gain: $1.75M × about 31.8% ≈ $557K
  • Ordinary income portion: $1.5M × 37% = $555K, plus Medicare taxes ≈ $35K (2.35%: the 1.45% Medicare rate plus the 0.9% Additional Medicare Tax for someone already over the wage base)
  • Total federal tax: about $1.15M
  • Net after federal tax: about $3.85M (roughly 77% retention)

The compensatory-tender outcome is roughly $360K worse than the clean-capital-gain outcome on the same $5M of proceeds, before state tax.

Scenario 3: Fund-led secondary as part of a Series D round, at FMV.

  • Proceeds: $5M, all capital gain (no compensation classification because the company isn’t the buyer or sponsor)
  • §1202: 50% exclusion at post-OBBBA year 3
  • Excluded: $2.5M
  • Taxable: $2.5M × about 31.8% ≈ $795K
  • Net after federal tax: about $4.21M (84.1% retention)

The fund-led secondary and the third-party tender at FMV produce roughly identical founder outcomes. The compensatory tender produces a meaningfully worse one.

State tax sits on top in all three scenarios. A California founder generally owes 13.3% state tax on the full $5M gain regardless of the federal treatment. An Oregon founder under SB 1507 owes 9.9% on the full gain. See our state-by-state conformity guide for the per-state math.

The §1045 rollover question

If the secondary lands before your QSBS hits the 5-year mark and you don’t want to recognize the gain, the §1045 rollover may be available. Two prerequisites: you must have held the QSBS for more than six months before the sale, and you must roll the proceeds into replacement QSBS within 60 days. The gain isn’t excluded; it’s deferred. Your basis in the replacement stock is reduced by the deferred gain, and your original holding period tacks onto the new shares, so the clock keeps running toward the exclusion tiers.

This works best for repeat founders who already have a credible replacement target. For most one-time secondaries, the rollover is impractical: you’d have to find and close on replacement QSBS inside two months. But it’s worth considering if you’re sitting on a $20M+ tender and have a new venture or QSBS-eligible vehicle ready.

The §1045 rollover doesn’t help with the compensation-income portion of a compensatory tender. The compensation is recognized in the year received. Only the capital-gain portion is rollable.

Trust-stacking interactions

If you have non-grantor trusts holding QSBS, each trust is its own taxpayer with its own §1202 exclusion. A secondary sale by a trust is generally a regular §1202 disposition for that trust.

Three things to coordinate:

  • Pro-rata participation. If the tender is offered at the cap-table level, each trust may need to participate independently. If the founder sells from their personal holdings while the trusts sit out, that can defeat the purpose of the stacking structure.
  • Trust holding periods. Under §1202(h), a trust that receives QSBS by gift is generally treated as having acquired the stock in the same manner as the founder, which preserves original-issuance status, and it includes the founder’s holding period (see also §1223(2)). Confirm each trust has crossed the relevant exclusion tier.
  • Trustee approval. A non-grantor trust is independently administered. The trustee, not the founder, makes the decision to participate. Coordinate well in advance of the tender deadline.

For the stacking mechanics, see our QSBS trust stacking guide.

Most common mistakes

Three patterns account for almost every secondary that goes worse than expected:

  • Not asking whether the tender is compensatory. Usually the most expensive mistake. A 30-minute conversation with the company’s tax counsel before signing can save hundreds of thousands in unexpected ordinary-income tax.
  • Selling QSBS at year 2.5 without considering the §1045 rollover. Pre-OBBBA stock that doesn’t reach 5 years generally gets no exclusion; post-OBBBA stock that doesn’t reach 3 years gets none either. The rollover can preserve the planning optionality if you have a replacement target.
  • Missing the cap-table-level redemption disqualification. A founder who participates in a tender funded by a company redemption can inadvertently taint QSBS for everyone else on the cap table, including their own remaining shares. The redemption structure matters as much as the founder’s own tax treatment.

What to do before you sign

Six questions for the company’s CFO and tax counsel before signing any secondary documents:

  1. Is the company itself the buyer, or is the buyer a third party (fund, family office, secondary specialist)?
  2. Is the tender price at or below the most recent 409A FMV, or is there a premium?
  3. If there’s a premium, has the company taken a position on whether the premium is compensation or capital gain? Get this in writing.
  4. If the company is funding the tender, what structure are they using? Does the structure involve redemptions above the significant-redemption threshold (more than 5% of the aggregate value of all the company’s stock)?
  5. What’s the QSBS impact analysis for the cap table? Has counsel run the §1202(c)(3) redemption test?
  6. Is the offer a one-time event or part of a structural cadence? Quarterly tenders have different planning considerations than one-time exits.

If the answers raise red flags, the conversation to have is with the company, not just with your own CPA. The company can often restructure the deal to clean up the tax treatment before close.

The bottom line

Three takeaways:

  1. A “clean” $5M founder secondary nets about $4.2M after federal tax with the §1202 partial exclusion at year 3. A compensatory $5M secondary nets closer to $3.85M. The structure matters as much as the price.
  2. QSBS treatment generally survives a founder’s own secondary sale, but secondary buyers generally don’t get QSBS. The bigger cap-table risk is the §1202(c)(3) redemption disqualification: a company-funded tender can taint surrounding QSBS issuances.
  3. Ask the six structural questions before you sign. Your CPA can model the tax after the fact, but the company’s tax counsel is usually the only one who can change the structure.

Promissory helps founders evaluate secondary opportunities against their broader QSBS planning, including trust-stacking impact and §1045 rollover options. If you have a tender offer on the table and want a pressure test on the after-tax math, schedule a consultation. See our pricing for transparent fixed fees.

This is general information, not tax or legal advice. The details of your situation matter; confirm them with your own advisors.