Vesting is one of those concepts that startup founders encounter early — in conversations with lawyers, in term sheets, in advice from investors — but that isn’t always explained clearly. The mechanics are straightforward once you understand them, and the reasons vesting exists are even more intuitive. What trips founders up is usually either not having vesting in place when they should, or not fully understanding what it means for their ownership when an investor requires it.
This article focuses specifically on founder vesting — how it works, why investors care about it, and what founders should think through before a raise. Employee and advisor equity are covered separately in our equity compensation overview.
What Is Vesting and Why Does It Exist?
Vesting is a schedule that determines when equity becomes fully owned by the recipient. Rather than receiving all of their shares unconditionally at the outset, a founder’s shares become permanently theirs over time — typically tied to continued service to the company.
Aligning Incentives Across Founders and Investors
The logic is straightforward. When a company has multiple founders, or when outside investors come in, everyone’s interests are aligned around the founders staying and doing the work. Vesting creates a structure where a founder who leaves early doesn’t walk away with the same ownership stake as one who stays for the full journey. It protects the company, protects the other founders, and protects investors who are betting on the team as much as the business.
The Problem Without Vesting
Without vesting, a co-founder who leaves six months after formation takes their full ownership stake with them — potentially holding a significant percentage of the company without contributing further. That creates cap table problems, complicates future raises, and can leave the remaining founders and the company in a difficult position.
How Founder Vesting Typically Works
The most common founder vesting schedule in venture-backed companies is four years with a one-year cliff. Understanding what that means in practice matters.
The One-Year Cliff
The cliff is a threshold period during which no shares vest. Under a four-year schedule with a one-year cliff, a founder who leaves before completing one full year receives nothing — their unvested shares are forfeited or subject to repurchase by the company. At the one-year mark, 25% of the total shares vest at once.
Monthly Vesting After the Cliff
After the cliff, the remaining shares typically vest in equal monthly installments over the following 36 months — each installment representing 1/48th of the total grant. The cliff filters out founders who leave very early, while monthly vesting after the cliff ensures ongoing alignment between ownership and contribution.
Acceleration Provisions
Some vesting schedules include an acceleration provision that speeds up vesting under certain circumstances. Single-trigger acceleration vests remaining shares upon one event, such as an acquisition. Double-trigger acceleration requires two events — typically an acquisition plus termination of the founder’s role. Investors generally prefer double-trigger because single-trigger can reduce incentives for founders to stay engaged through a transaction.
The Difference Between Restricted Stock and Options for Founders
Founders typically receive restricted stock rather than stock options — a distinction that matters for both ownership structure and tax treatment.
How Stock Options Work
Stock options are the right to purchase shares at a fixed exercise price in the future and are the standard vehicle for employee equity compensation. Options are typically granted after formation, when the company has an established fair market value.
How Restricted Stock Works
Restricted stock means the founder actually owns shares from the outset, but those shares are subject to a company repurchase right. If the founder leaves before fully vesting, the company can repurchase the unvested portion at cost (or, under some agreements, the lower of cost or fair market value) — which for founder stock is typically very low. As shares vest, the repurchase right lapses and those shares become permanently owned.
The 83(b) Election: A Critical and Time-Sensitive Filing
The tax treatment of restricted stock makes one decision particularly time-sensitive: the 83(b) election under Internal Revenue Code § 83(b). This is a filing made with the IRS within 30 days of the transfer of restricted stock that allows a founder to recognize taxable income — measured as the fair market value at the time of transfer minus any amount paid — at the time of the transfer rather than as shares vest over time. The election also starts the holding period for long-term capital gains treatment at the date of transfer.
Because the stock is typically valued very low at formation (often at par value of $0.0001 per share), making this election means the taxable income recognized is near zero. Without the election, income would be recognized at vesting, when the shares may be worth substantially more. The 30-day window is strict and set by statute (IRC § 83(b)(2)) — missing it eliminates the option entirely, and the IRS has consistently refused late filings.
What Happens When Investors Require Vesting
As discussed in the context of founder agreements, investors — particularly institutional venture investors — will expect founder vesting to be in place. If it isn’t, they will typically require it as a condition of the investment.
Credit for Time Already Served
When vesting is imposed at the time of a financing rather than at formation, the dynamics are a little different. Investors will generally agree to give founders credit for time already served — meaning a founder who has been building for two years before a Series A might be given two years of deemed vesting, with the remaining two years of a four-year schedule still to run. The specific terms are negotiable, but the principle is the same: the investor wants to know that the founders are committed going forward.
Why Setting Up Vesting at Formation Is Better
Having vesting in place at formation — rather than waiting for investors to require it — is simpler, cleaner, and avoids a negotiation that can feel uncomfortable when you’re trying to close a deal.
A Foundation Decision Worth Getting Right
Founder vesting is one of those structural decisions that feels abstract until it isn’t. A co-founder departure, an acquisition conversation, or an investor’s term sheet can bring it into focus quickly. The founders who navigate those moments most smoothly are usually the ones who set it up deliberately at the start, made their 83(b) elections on time, and didn’t leave the question for investors to resolve later.
If you are forming a company and want to think through your vesting structure, or approaching a raise and want to understand how vesting will be addressed, I am glad to help you work through it.
Frequently Asked Questions
What is founder vesting?
Founder vesting is a schedule that determines when a founder’s equity becomes permanently and unconditionally owned. Rather than owning shares outright from day one, a founder earns ownership over time — typically tied to continued service to the company. Shares that haven’t vested when a founder leaves are forfeited or repurchased by the company.
What is a vesting cliff?
A vesting cliff is a threshold period at the beginning of a vesting schedule during which no shares vest. Under the most common schedule — four years with a one-year cliff — a founder who leaves before completing one year receives nothing. At the one-year mark, 25% vests at once, with the remainder vesting in equal monthly installments (each representing 1/48th of the total grant) over the following three years.
What is an 83(b) election and why does it matter?
An 83(b) election is a filing made with the IRS within 30 days of the transfer of restricted stock, pursuant to Internal Revenue Code § 83(b). It allows a founder to recognize taxable income at the time of transfer — when the stock is typically worth very little — rather than as shares vest over time. Because founder stock is usually purchased at nominal value, the election results in near-zero taxable income at grant. Without it, income is recognized at vesting when shares may be worth significantly more. The 30-day window is set by statute and is strict — missing it eliminates the option entirely.
What is the difference between single-trigger and double-trigger acceleration?
Single-trigger acceleration vests some or all remaining shares upon a single event, such as an acquisition. Double-trigger acceleration requires two events — typically an acquisition plus the founder’s termination — before unvested shares accelerate. Investors generally prefer double-trigger because it keeps founders engaged through a transaction and preserves retention incentives for the acquiring company.
Do all startups need founder vesting?
Founder vesting is not legally required, but it is practically essential for any company planning to raise institutional capital or bring in outside investors. Investors expect it, and companies without founder vesting in place will typically have it imposed as a condition of investment. Setting it up at formation — when the founder agreements are being drafted — is simpler and avoids a negotiation at an inconvenient time.
What happens to unvested shares if a founder leaves?
The company typically has the right to repurchase unvested shares at cost (or, under some agreements, the lower of cost or fair market value) — which for founder stock is usually very low. The specifics depend on the terms of the founder’s restricted stock purchase agreement. Vested shares are permanently owned and generally not subject to repurchase on departure.
