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ASC 718 Stock Compensation — The Complete Guide

12 min read • Updated 2025

What Is ASC 718?

ASC 718 (formerly SFAS 123R) is the US GAAP standard that governs how companies account for share-based compensation — stock options, restricted stock units (RSUs), and other equity awards granted to employees and directors.

The core principle is straightforward: measure the fair value of equity awards on the grant date and recognize that amount as compensation expense over the vesting period. In practice, this involves option-pricing models, volatility estimation, and a fair amount of judgment.

Who Needs to Comply?

Every entity that issues share-based compensation — from Series A startups to public companies. If you grant stock options or RSUs, you need an ASC 718 valuation to record the expense in your financial statements.

  • Pre-IPO startups — Required for audited financial statements, often starting at Series A when auditors first engage.
  • Private companies — Needed for any GAAP-compliant financials, M&A due diligence, or SOX readiness.
  • Public companies — Mandatory for SEC filings; compensation expense directly impacts EPS.

The Fair Value Framework

ASC 718 requires fair value to be measured at the grant date using an accepted option-pricing model. The two most common are:

Black-Scholes-Merton

Closed-form model. Preferred for "plain vanilla" options with standard vesting and a single expected term. Most startups use this.

Lattice (Binomial)

More flexible — can model early exercise behavior and changing volatility over time. Used by larger companies with complex award structures.

Key Inputs

Regardless of the model, you need these inputs:

InputSource
Stock price (S)409A valuation for private cos; market price for public
Strike price (K)Set in the option agreement (often = common FMV at grant)
Expected term (T)Simplified method or historical exercise data
Volatility (σ)Comparable public companies (for private cos)
Risk-free rate (r)US Treasury yield matching the expected term
Dividend yield (q)Usually 0 for startups

Expected Term — The Simplified Method

Private companies without sufficient historical exercise data can use the SAB 107/110 simplified method:

Expected Term = (Vesting Period + Contractual Term) / 2

For a typical 4-year vest with a 10-year contractual term, this gives 7 years. This is the most common approach for startups and is explicitly accepted by auditors.

Expense Recognition

Once you have the per-share fair value, multiply by the number of options granted to get the total compensation cost. This is recognized ratably over the requisite service period (usually the vesting period):

  • Straight-line — Equal expense each period (most common for single awards).
  • Graded vesting — Each vesting tranche is treated as a separate award; front-loads expense.

Forfeitures can be estimated upfront or recognized as they occur (ASU 2016-09 election). Most private companies now elect to recognize forfeitures when they happen, as it's simpler.

What Auditors Look For

  • Documented rationale for comparable company selection
  • Consistency in lookback period and frequency across grants
  • Sensitivity analysis showing fair value across a range of volatilities and rates
  • Board-approved grant dates matching the valuation date
  • Reconciliation of total stock-based compensation expense to the financial statements

Common Mistakes

Mistake
Using a single comp. Use 3–10 comparable companies to support the median volatility.
Mistake
Ignoring lookback period. Match the lookback window to the expected term for consistency.
Mistake
Stale 409A price. Ensure the common stock price reflects the most recent 409A, especially after a funding round.
Mistake
Missing sensitivity analysis. Show how fair value changes with ±10% sigma and ±50 bps risk-free rate.

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