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IRS 409A Penalties: What Happens Without a Compliant Valuation

IRS Section 409A penalties are triggered when stock options are granted below fair market value without safe harbor protection, resulting in immediate ordinary income taxation, a 20% federal excise tax, interest charges on underpayments, and potential state penalties of up to an additional 20%.

Published April 20, 2026
3 min read

Key Takeaways

  • 409A violations trigger immediate income tax on the full spread at vesting — before any shares can be sold
  • The 20% federal excise tax applies on top of ordinary income tax
  • California and several other states add a further 20% state excise tax
  • The company faces payroll tax withholding failures and penalties
  • IRS can look back at option grants for the past 6 years in an audit
  • Correction programs exist but are complex, costly, and not always available

The Full Cost of a 409A Violation

The penalties under Section 409A are deliberately punitive — Congress designed them to ensure that deferred compensation tax deferral is not abused. For employees holding options that were granted below FMV, the financial consequences can be devastating, particularly if the options have not yet vested and the employee has no liquidity to pay the tax bill.

Federal Penalties: The 20% Excise Tax

When a 409A violation is triggered (typically at vesting of options granted below FMV), the following federal tax consequences apply:

  1. Ordinary income tax: The full "spread" (FMV at vesting minus strike price) is included in the employee's gross income in the year of vesting. For a Silicon Valley engineer in the highest bracket, this means approximately 37% federal income tax.
  2. 20% excise tax: An additional 20% federal excise tax under §409A applies to the amount of deferred compensation that is included in income. This is on top of, not instead of, ordinary income tax.
  3. Interest: Underpayment interest at the IRS federal short-term rate plus 1% applies from the later of the vesting date or the first year the compensation was no longer subject to substantial risk of forfeiture.

Combined, an employee could face an effective marginal tax rate of 57%+ on unvested options in a 409A violation scenario.

State-Level Penalties

Several states have enacted their own §409A-equivalent penalty taxes:

  • California: 20% state excise tax on top of federal — combined federal + state marginal rate can exceed 77%
  • New York: Conforms to federal §409A treatment; no additional state penalty but high income tax rates
  • New Jersey: State income tax on the spread but no separate excise tax

Company-Level Consequences

The company also faces consequences when a 409A violation occurs:

  • Withholding failures: The company is required to withhold income tax and employment taxes on the spread at vesting. If it fails to do so, it faces penalties under IRC §6672 (Trust Fund Recovery Penalty) and interest.
  • W-2 reporting errors: Failed withholding may require amended W-2s for prior years, triggering additional penalties
  • D&O liability: Officers who were aware of the violation may face claims from employees harmed by the tax consequences
  • Investor scrutiny: Discovered in M&A due diligence, unresolved 409A violations can delay or reduce deal value

IRS Correction Programs

In limited circumstances, 409A violations can be corrected under IRS Notice 2008-113. Corrections are only available for:

  • Operational failures (not document failures)
  • Corrections made in the same year as the failure, or within two years for certain inadvertent errors

Corrections are complex, require legal counsel, and are not always available. Prevention — through timely, qualified 409A valuations — is far less costly than correction.

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