I handle 409A valuations for startups regularly and wanted to provide some substantive guidance here since the existing replies are quite general. A 409A valuation is not optional if you are granting stock options. Under IRC Section 409A, if options are granted at below fair market value, the recipient faces a 20 percent penalty tax plus interest on the deferred compensation.
The standard approach for early-stage startups is to hire an independent valuation firm. These typically cost between $3,000 and $10,000 depending on company stage and complexity. The resulting report creates a safe harbor under Treasury Regulation 1.409A-1(b)(5)(iv), meaning the IRS will presume the valuation is reasonable unless it can demonstrate gross unreasonableness.
Timing matters significantly. A 409A valuation is generally valid for 12 months unless a material event occurs that would change the company value, such as a new funding round, a significant revenue milestone, or a major pivot. If you raised a priced round since your last 409A, you almost certainly need a new one before granting additional options.
One practical tip: coordinate your 409A valuation with your option grant schedule. Many startups do quarterly grant cycles and refresh their 409A annually or after any material event. This minimizes costs while keeping you compliant. Also make sure your board formally approves the 409A valuation and documents the grant price in the board minutes.