If you grant stock options at a startup, you need a 409A valuation. The phrase sounds like compliance trivia, but the consequences of getting it wrong land directly on your employees -- in the form of a 20 percent federal excise tax, state penalties, and accumulated interest. The consequences of getting it right are invisible, which is why the 409A gets less attention than it deserves until it matters.
This guide covers what a 409A valuation actually is, when you need one, how it is done, what it costs, and the specific things founders get wrong.
The Short Answer
A 409A valuation is an independent appraisal of the fair market value of your company's common stock. It exists for one reason: the IRS requires you to set option strike prices at or above fair market value, and without a defensible valuation, the IRS decides for you -- usually unfavorably.
The "409A" refers to Section 409A of the Internal Revenue Code, enacted in 2004 in the wake of the Enron era, when executives had structured deferred compensation in ways that avoided tax on economic value received. Congress wrote Section 409A to close that loophole. It applies to any "nonqualified deferred compensation," which the IRS interprets to include stock options priced below fair market value.
Why Section 409A Exists
Before 2004, a company could grant options with a strike price below the actual stock value and argue that the employee did not have taxable income until the option was exercised. The IRS disagreed and Congress codified that disagreement.
Under the current rules, an option granted with a strike price below fair market value is immediately subject to:
- Federal income tax on the spread between strike and fair market value, at the moment of vesting (not exercise).
- A 20 percent federal excise tax on top of ordinary income tax.
- A 1 percent per month interest charge on the deferred tax.
- Equivalent state penalties in states that conform to federal rules (most do).
In practical terms, an employee whose options were priced too low can end up owing tax before they have sold a single share. The penalty falls on the employee, not the company. But the reputational damage to the founder is usually severe.
When You Need a 409A Valuation
You need a 409A valuation when any of the following happens:
You grant your first stock option. Before that point, you have no mechanism to set a strike price, and the IRS considers any grant to be at fair market value only if you can prove it.
You complete a priced equity round. A priced round is a material event that changes fair market value. The previous 409A is no longer defensible for new grants.
Twelve months have passed since your last 409A. Safe harbor treatment (discussed below) requires a valuation no older than 12 months.
A material event occurs. Acquisition offer, unexpected revenue inflection, major commercial contract, or significant financial restructuring can all invalidate the prior 409A before the 12-month mark.
Most seed-stage startups will do one 409A when they first hire employees and another after each priced round. Series A and later companies typically refresh every 12 months as a matter of course.
What "Safe Harbor" Means
This is the most important concept in 409A compliance and the one founders most often misunderstand.
A 409A valuation establishes a strike price. If the IRS later disputes that price, the burden of proof is normally on the company to justify it. Under safe harbor, the burden shifts to the IRS. The IRS can only challenge a safe-harbor valuation by proving it was "grossly unreasonable."
There are three ways to qualify for safe harbor:
Independent appraisal method. A qualified independent appraiser issues a valuation report. This is what Carta, Pulley, and specialist 409A firms provide. It is the standard safe harbor for venture-backed startups and the one we recommend for almost every case.
Illiquid startup method. For companies under 10 years old, without publicly traded securities, and without a reasonable expectation of IPO or sale within 12 months, a valuation performed by someone with "significant knowledge and experience" can qualify. The definition is flexible but the documentation burden is heavy.
Formula method. Restricted use. Requires that the formula apply to every transaction in the same class of stock, including compensatory and non-compensatory. Rarely used.
The independent appraisal method is cheap enough ($1,000 to $5,000 for most startups) that the other two are rarely worth the risk.
The Three Valuation Methodologies
An appraiser will typically apply one or more of the following:
Market Approach
Values the company based on comparable public companies or recent transactions in similar private companies.
For early-stage startups, the market approach is the dominant methodology when there is a recent priced round. The preferred share price from that round establishes enterprise value, which the appraiser then allocates across share classes.
Income Approach
Values the company based on projected future cash flows, discounted to present value. This is the classic DCF methodology.
For pre-revenue startups, the income approach is usually not reliable -- there are no cash flows to discount. For Series B and later companies with stable revenue, it becomes more relevant.
Asset Approach
Values the company based on the net fair value of its assets and liabilities. For startups, this is typically a floor value and rarely the primary methodology.
How Common Stock Gets Priced Below Preferred
The price of the preferred stock in a priced round is not the same as the price of the common stock. Preferred carries a liquidation preference, which means in a downside scenario the preferred holders get their money back before common holders see anything.
That preference has real economic value. A 409A appraiser quantifies it and subtracts it from enterprise value to arrive at the common stock price.
In practice, the common-to-preferred discount at seed stage is typically 20 to 40 percent. At Series A, it narrows to 15 to 30 percent. By Series C, it may be 10 to 20 percent. As the company matures and the probability of a strong exit rises, the liquidation preference matters less and the discount shrinks.
This is why you can raise at a $30 million post-money valuation and have a common stock 409A of $0.18 per share. It is not a trick. It is the economic reality of the preference stack.
Allocation Methods: OPM vs. PWERM
Most 409A reports use one of two allocation methods to split enterprise value across share classes:
Option Pricing Method (OPM). Treats each share class as a call option on the company's enterprise value, using Black-Scholes to price the options. Appropriate for early-stage companies where the exit scenario is highly uncertain.
Probability-Weighted Expected Return Method (PWERM). Models specific exit scenarios (IPO, acquisition, dissolution) and weights their probabilities. Appropriate for later-stage companies where specific exit paths are identifiable.
Seed and Series A startups almost always use OPM. Series B and later may use PWERM or a hybrid. Your appraiser will pick; you should understand why.
What a 409A Costs
Typical pricing in 2026:
- Cap table platforms (Carta, Pulley). $1,000 to $2,500 per valuation, bundled with cap table management. Fast turnaround (2 to 4 weeks) and tightly integrated with your 83(b) and option grant workflows.
- Specialist appraisers. $3,000 to $7,500 for a standalone valuation. Slower turnaround (3 to 6 weeks) but more defensible in edge cases (distressed, cross-border, unusual share structures).
- Big Four or independent CPAs. $10,000 and up. Overkill for most startups. Appropriate if you are preparing for an audit or acquisition where a bigger name on the report matters.
Most seed-to-Series-B startups use a cap table platform. The defensibility is sufficient for normal IRS scrutiny, and the workflow integration is worth the small premium over independents.
What Happens If You Get It Wrong
The penalty falls on the employee who received the underpriced option, not on the company. But the company is nearly always pulled in.
In practice, the sequence looks like:
- The IRS audits an employee (or the company) and identifies options priced below fair market value.
- The employee owes back taxes plus the 20 percent excise plus interest.
- The employee -- reasonably -- blames the founder for issuing options at a strike price the founder chose.
- The company often covers the shortfall through a "gross-up" to make the employee whole, which is itself taxable compensation.
The best case is a five-figure mess. The worst case is a seven-figure mess at a late-stage company with many underpriced grants.
Common Mistakes
Granting options without a 409A in place. The most common mistake at pre-seed. Founders make verbal option promises, or issue grants at a strike price they guessed at. There is no defensible fair market value and no safe harbor.
Letting a 409A expire during hiring. A 14-month-old 409A does not qualify for safe harbor. If you are actively hiring, track the expiry date and refresh before it matters.
Ignoring material events. Raising a priced round, receiving an acquisition offer, or signing a transformative commercial contract all invalidate the prior 409A. Many founders refresh only on the 12-month clock and miss interim triggers.
Using the preferred share price as the common strike price. A costly error. The common stock is always priced lower. An appraiser does the math; do not guess.
Grant dates that precede the 409A effective date. The option grant date must be on or after the 409A's valuation date. Backdating is illegal and will be discovered in any meaningful audit.
What We Recommend
For most startups:
- Use Carta or Pulley for your 409A alongside cap table management.
- Refresh every 12 months on a recurring calendar, plus after any priced round or material event.
- Keep the report, the board resolutions approving the grants, and the individual option grant agreements in a dedicated diligence folder.
- When in doubt about whether an event is "material," refresh. The cost is low. The downside of not refreshing is not.
If you have granted options without a valid 409A in place, fix it now, not later. The remediation is less painful before an audit or a diligence process surfaces the problem.
A 409A valuation is offered as an add-on to our fractional CFO service. If you need one or are not sure whether your current valuation still qualifies for safe harbor, book a free consultation and we will walk through the specifics.
