409A FMV: Valuation Methods, Penalties, and Pitfalls

A 409A FMV is the fair market value of one share of a private company’s common stock, calculated under rules set by Section 409A of the Internal Revenue Code and used as the minimum exercise price for stock options granted on that date. Price options at or above that number and they sit outside Section 409A entirely. Price them below it and the option holder faces ordinary income tax, a flat 20% federal penalty, and premium interest running back to the year the compensation was first deferred.¹

Why the Number Exists at All

Section 409A governs nonqualified deferred compensation: any arrangement where you earn pay now and receive it later. Stock options technically fit, because you receive the right to buy shares today but collect no value until you exercise. The Treasury regulations carve out an exemption, though. If the exercise price is at least equal to the underlying stock’s fair market value on the grant date, the option is not treated as deferred compensation, and none of Section 409A’s timing rules or penalties apply.²

A public company can read the exemption off a stock ticker. A private company has no market price, so it needs a defensible number. That number becomes the floor for the exercise price of every option granted until the next valuation cycle. Undershoot by even a penny and the exemption is gone.

What Pricing Below FMV Actually Costs the Employee

When an option is granted below fair market value, it becomes deferred compensation subject to Section 409A. If the arrangement doesn’t meet 409A’s strict rules, the compensation becomes taxable as it vests, even though the employee hasn’t exercised the option or received any cash. The tax hit stacks in three layers.

Ordinary income tax on the deferred amount, at rates reaching 37% for 2026.³
A flat 20% additional federal tax on the same amount.¹
Premium interest at the federal underpayment rate plus one percentage point, calculated as if the income should have been reported in the year the compensation was first deferred or first vested, whichever came later.¹

Add state income tax, and in some states a separate state-level 409A penalty, and the combined bite can exceed 60% of the deferred amount. The penalties fall on the employee, not the company. Rank-and-file workers who had no say in how the exercise price was set carry the tax bill for the mistake.

The Three Safe Harbor Valuation Methods

Any reasonable method can support a valuation, but only three approaches earn safe harbor treatment. Safe harbor creates a presumption of reasonableness: the IRS must show the valuation or its application was grossly unreasonable before it can impose penalties. Without safe harbor, the company carries the burden of proving the price was right.²

Independent Appraisal

The strongest and most common method. A qualified independent appraiser produces a written report meeting the standards used for ESOP valuations under Section 401(a)(28)(C), dated no more than 12 months before the grant date.² The appraiser reviews financials, projects earnings, benchmarks against comparable public companies, and adjusts for the fact that private shares are hard to sell. Fees typically run from around $2,000 for very early-stage startups to $15,000 or more for mature private companies approaching an exit.

Illiquid Startup Method

Younger companies can do the work internally. The company must have been in its current trade or business for fewer than 10 years and cannot have publicly traded stock. The person performing the valuation needs significant experience, generally meaning at least five years in business valuation, financial accounting, investment banking, private equity, secured lending, or a comparable field in the company’s industry.⁴ A board member or CFO with the right background can qualify.

The method is off-limits if the company reasonably anticipates a change of control within 90 days or a public offering within 180 days of the grant date.⁴ The result still needs a written report explaining the methodology. Most companies switch to an independent appraisal after their first priced round, because an arm’s-length preferred price creates allocation questions that are hard to defend without a third-party analysis.

Binding Formula Method

A fixed formula, usually written into a shareholder buy-sell agreement or corporate charter, can also anchor the price. The formula has to function as a permanent restriction on the stock’s transfer price and be applied consistently to every transfer of that class of stock, compensatory or not. Use the formula for option grants and a different price when a founder sells to an investor and the safe harbor fails.² Venture-backed companies rarely qualify because funding rounds set arm’s-length prices that ignore any formula. It’s mostly a fit for closely held businesses with stable ownership.

How Appraisers Get to the Common Stock Number

At a venture-backed company, preferred shares held by investors and common shares issued to employees are different classes with different rights. Preferred usually carries liquidation preferences, anti-dilution protections, and conversion rights that make it more valuable per share. The appraiser’s job is to isolate the value of the common alone, which is always lower.

The most common approach after a recent funding round is the option pricing model backsolve. The appraiser works backward from a known data point, typically the price per share of the latest preferred round, and uses an option pricing framework to allocate the company’s total equity value across each class of stock based on its specific economic rights. Preferred gets paid first in most exit scenarios, so common ends up with a smaller slice.

Two further discounts apply once value has been allocated to the common. The discount for lack of marketability reflects that private shares cannot be freely sold on an exchange. The discount for lack of control reflects that common shareholders typically cannot steer corporate decisions the way controlling shareholders can.⁵ Together, these discounts often bring the common stock value to a fraction of the most recent preferred price, sometimes 20% to 40% of what investors just paid per share in an early round.

How Long a 409A Valuation Lasts

An independent appraisal is presumptively valid for up to 12 months from its effective date. A company can grant options throughout that window using the same price. The regulations are explicit, though, that a prior value stops being reasonable once new information becomes available that could materially affect the company’s worth.²

The most common early trigger is a new priced funding round. When investors set a price for a round of preferred, they establish an arm’s-length data point the company has to reckon with in its next grants. Other triggers include signing a letter of intent for an acquisition, a significant shift in revenue trajectory, resolution of major litigation, or issuance of a key patent. Company-sponsored tender offers almost always require a fresh appraisal, because the tender price becomes a strong indicator of common stock value. Unsanctioned secondary sales between individual shareholders are a softer trigger, and small-volume transactions may not require a full new report.

Waiting out the calendar when circumstances have already changed does not preserve the safe harbor. Granting options against a stale valuation after a material event defeats the presumption, even if the report is technically less than a year old.

Where the 409A FMV Meets the 83(b) Election

Employees who exercise stock options early, before the shares fully vest, can file a Section 83(b) election to be taxed at the time of exercise rather than at vesting. The election must be filed with the IRS within 30 days of the exercise date.⁶ The taxable amount is the difference between the fair market value on the exercise date and the price paid.

The 409A number is that fair market value. Exercise shortly after grant, when the exercise price is close to the current 409A FMV, and the spread is small or zero, meaning little or no immediate tax. Wait until the 409A FMV has climbed, and the spread at exercise is larger, and the ordinary income tax is bigger. Timing the exercise relative to the valuation cycle changes the tax cost meaningfully.

Fixing a Bad Valuation Before the IRS Finds It

Options do get granted below fair market value. The company used a stale report, miscalculated the price, or never obtained a proper valuation in the first place. The IRS runs two correction programs that can shrink or eliminate the 20% penalty and interest, depending on timing.

Notice 2008-113 covers operational failures, where the plan documents were correct but the company didn’t follow them. Catch the mistake in the same tax year and it can often be fixed with a price adjustment or repayment of any excess amount, with no additional tax. Corrections in the following tax year are available to employees who are not corporate insiders. Relief requires that the failure was inadvertent, the company takes steps to prevent recurrence, and the relevant return is not already under examination.⁷

Notice 2010-6 addresses document failures, where the plan itself was written in a way that violates Section 409A. Correction without income inclusion or additional taxes is possible if the fix doesn’t affect how the plan actually operates within one year after the correction date. First-time plan failures get more favorable treatment if corrected within a limited window after adoption. Both programs require attaching specific information to the company’s return, providing details to the affected employee, and having the employee attach corresponding information to their own return.⁸

Neither program is available if the failure was intentional or if the taxpayer is already under IRS examination for the year at issue. The earlier a mistake is caught, the better the outcome.

Pitfalls That Create the Problem in the First Place

Most 409A issues aren’t deliberate underpricing. They come from timing gaps and administrative oversights.

Granting options before the first valuation. Some early-stage companies issue options at a nominal price like $0.01 per share before ever commissioning a 409A report. If the company has any real value, those options are almost certainly below fair market value.
Ignoring material events. A company closes a Series B in March but keeps granting at the pre-round 409A price through June because the report hasn’t technically expired. The round likely invalidated the old price regardless of the calendar.
Backdating grant dates. Setting the grant date to a time when the 409A price was lower rather than the date the board actually approved the grant. That creates a below-market exercise price and a 409A violation.
Using preferred prices as a shortcut. The 409A FMV is a common stock number. Setting the exercise price equal to the preferred price overstates value and isn’t a 409A problem, but applying an informal discount to the preferred price without a formal allocation methodology can create one.

The best prevention is a board policy requiring a current 409A valuation before any option grants and an automatic new valuation whenever the company closes a priced round or signs a term sheet for an acquisition. Building those checkpoints into the equity grant process costs nothing and heads off the kind of mistake that is very expensive to fix later.

1
Office of the Law Revision Counsel. 26 USC 409A – Requirements for Nonqualified Deferred Compensation Plans
2
eCFR. 26 CFR 1.409A-1 – Definitions and Covered Plans
3
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
4
eCFR. 26 CFR 1.409A-1 – Definitions and Covered Plans
5
Internal Revenue Service. Discount for Lack of Marketability Job Aid for IRS Valuation Professionals
6
Office of the Law Revision Counsel. 26 USC 83 – Property Transferred in Connection With Performance of Services
7
Internal Revenue Service. Relief for Certain Operational Failures Under Section 409A
8
Internal Revenue Service. Relief and Guidance on Corrections of Certain Failures of a Nonqualified Deferred Compensation Plan to Comply With Section 409A