Equity is how founders get compensated for the risk they take building a company. But equity without a vesting schedule is a governance and investment risk that can kill your startup—or at least, your fundraising prospects. A founder vesting agreement is the document that ties equity ownership to the commitment to stay and build.
Here’s what you need to know before your first investor conversation.
What Is a Founder Vesting Agreement?
A founder vesting agreement (sometimes called a restricted stock purchase agreement or equity vesting agreement) is a contract that makes a founder’s equity ownership contingent on continued involvement with the company over a period of time—typically four years. If a founder leaves before their shares are fully vested, the company can repurchase the unvested portion, usually at the price originally paid (often a nominal amount).
Vesting solves a fundamental problem: without it, a co-founder can walk away with 33% of the company after three months—leaving two remaining founders to do all the work while a ghost co-founder collects a third of the exit proceeds. No rational investor will fund a company where this is possible.
Standard Vesting Terms
Four-Year Vesting with One-Year Cliff
The standard Silicon Valley and startup convention, widely used in Illinois:
- One-year cliff: No equity vests for the first 12 months. At the one-year anniversary, 25% of total shares vest all at once.
- Monthly vesting thereafter: The remaining 75% vests in equal monthly increments over the next 36 months.
- Total duration: 48 months (4 years) for 100% vesting.
The cliff protects co-founders and investors from a scenario where one founder leaves in month 2 with a significant equity stake. If someone isn’t working out, the cliff ensures they leave with nothing (or very little).
Alternative Vesting Schedules
- Three-year vesting, monthly: Common for later hires, shorter commitment periods
- Performance-based vesting: Vesting tied to milestones (revenue targets, product launches) rather than time—complex and can create disputes
- Reverse vesting for existing companies: When an investor joins or a new co-founder comes on, vesting is applied to previously-issued shares going forward
What Is a Section 83(b) Election and Why Does It Matter?
When you receive restricted stock (shares subject to vesting and repurchase), you have a tax choice to make within 30 days of the grant date. This is the Section 83(b) election.
Without a Section 83(b) election: You pay ordinary income tax on the fair market value of shares as they vest. If your company’s value grows significantly by your vesting dates, you’re paying income tax on the appreciated value—potentially a large amount, and potentially before you’ve received any cash.
With a Section 83(b) election: You elect to recognize the full value of all shares at grant (when the value is typically very low—often par value or nominal consideration). You pay tax now on a small amount; future appreciation is taxed at capital gains rates when you sell. For most founders, this is a significant tax advantage.
The 83(b) election must be filed with the IRS within 30 days of the grant. Miss the deadline, and the election is permanently unavailable. This is non-negotiable—it is one of the most time-sensitive legal steps for any founder receiving restricted equity.
Acceleration: What Happens at Acquisition?
Vesting agreements typically address what happens to unvested shares if the company is acquired. There are three common approaches:
| Approach | What Happens to Unvested Shares at Acquisition |
|---|---|
| No acceleration | Unvested shares remain subject to vesting under acquirer’s terms; you keep working to earn them |
| Single trigger acceleration | All unvested shares vest immediately upon acquisition, regardless of what happens to your employment |
| Double trigger acceleration | Unvested shares vest only if two events occur: acquisition AND termination without cause or resignation for good reason |
Investors typically prefer double-trigger acceleration because it retains founder incentive to stay post-acquisition. Founders typically prefer single-trigger because it protects them if the acquirer doesn’t retain them. Double-trigger is the market standard for startup founders.
What Does a Vesting Agreement Actually Contain?
- Number of shares issued and purchase price
- Vesting schedule (cliff, monthly increment, total duration)
- Company’s repurchase right for unvested shares upon termination
- Definition of termination events (voluntary resignation, termination for cause, termination without cause, disability, death)
- Acceleration provisions (if any)
- Right of first refusal on transfer of vested shares
- Section 83(b) election acknowledgment and filing obligation
FAQ: Founder Vesting Agreements
What if one founder already has shares without vesting?
Before raising outside capital, you should retroactively apply vesting to existing shares. This is called “reverse vesting” or a “restricted stock grant on top of existing equity.” Investors will require it. The 83(b) election timing applies from the date of the new restricted stock grant.
Can vesting agreements be modified?
Yes, with the consent of the parties. Vesting schedules can be accelerated by the board or modified by agreement. They cannot be unilaterally changed by the company to the founder’s detriment.
Fitter Law helps Illinois founders establish vesting agreements, restricted stock grants, and equity structures for co-founder teams and investor-ready cap tables. Learn about our startup formation services or view our flat-fee packages.