The engineer had been at the startup for 11 months when he got a better offer. He assumed his equity would transfer or pay out. It didn't. Because of the one-year cliff, he walked away with nothing—despite having worked there almost a full year.
"Nobody explained the cliff to me," he said.
This is common. Engineers accept equity as part of their compensation package without fully understanding when—and if—that equity becomes theirs. Vesting isn't complicated, but getting it wrong can cost hundreds of thousands of dollars.
Here's everything engineers need to know[^1].
Vesting Fundamentals
Vesting is the process by which your equity becomes yours over time. You're granted a certain amount, but you "earn" it gradually based on continued employment.
Why Vesting Exists
| Purpose | Explanation |
|---|---|
| Retention | Creates incentive to stay |
| Alignment | Rewards long-term commitment |
| Protection | Prevents early departure with full equity |
| Fairness | Equity earned matches time contributed |
From the company's perspective, vesting ensures that equity goes to people who contribute over time, not those who join briefly and leave.
The Standard Vesting Schedule
The most common vesting schedule is:
4 years, 1-year cliff, monthly thereafter
| Component | Meaning |
|---|---|
| 4 years total | Equity vests over 48 months |
| 1-year cliff | Nothing vests until 12 months |
| Monthly after cliff | 1/48th vests each month |
Here's how 100,000 options would vest:
| Timeline | Vested | Unvested |
|---|---|---|
| Month 0 (start) | 0 | 100,000 |
| Month 6 | 0 | 100,000 |
| Month 12 (cliff) | 25,000 | 75,000 |
| Month 18 | 37,500 | 62,500 |
| Month 24 | 50,000 | 50,000 |
| Month 36 | 75,000 | 25,000 |
| Month 48 (fully vested) | 100,000 | 0 |
After the cliff, you vest monthly: 100,000 ÷ 48 = 2,083 options per month.
The Cliff Explained
The cliff is the most important—and most misunderstood—vesting component.
What Happens at the Cliff
| Timeline | What Happens |
|---|---|
| Before cliff (months 0-11) | Nothing has vested; leaving = $0 |
| At cliff (month 12) | 25% vests immediately |
| After cliff (months 13+) | Additional vesting monthly |
The cliff exists to protect companies from employees who leave very early. If someone joins for 3 months and leaves, the company doesn't want them owning meaningful equity.
Cliff Variations
| Cliff Type | Typical Use |
|---|---|
| 1-year cliff | Standard for most roles |
| 6-month cliff | Sometimes for senior hires |
| No cliff | Rare; sometimes for executives |
| Backloaded cliff | More vests at year 1 than later years |
Some companies, especially later-stage ones, offer 6-month cliffs for senior candidates. This can be negotiated.
The Cliff Risk
| Scenario | What Happens |
|---|---|
| Quit at month 11 | 0% vested, lose everything |
| Fired at month 11 | 0% vested, lose everything |
| Quit at month 12 | 25% vested, keep those options |
If you're considering leaving near the cliff, wait until after month 12. The difference between month 11 and month 13 is the difference between nothing and 25%+.
Vesting Schedule Variations
Not all companies use the standard 4-year schedule.
By Company Type
| Company Type | Common Schedule |
|---|---|
| Early-stage startup | 4 years, 1-year cliff |
| Growth-stage startup | 4 years, 1-year cliff |
| Late-stage/pre-IPO | 4 years, 1-year cliff (RSUs) |
| Public company | 4 years, annual vesting (RSUs) |
| Big Tech | Various (often 4-year, variable) |
Notable Variations
| Company | Known Variation |
|---|---|
| Amazon | 5/15/40/40 backloaded vesting |
| Some startups | 3-year vesting total |
| Exec packages | Custom schedules |
Amazon's notorious backloading means you get only 5% in year 1 and 15% in year 2, with 80% coming in years 3-4. This significantly changes the value calculation compared to standard monthly vesting.
Acceleration Clauses
Acceleration means your vesting speeds up—you get unvested equity immediately.
Single-Trigger Acceleration
| What It Is | Vesting accelerates on one event (usually acquisition) |
|---|---|
| When It Happens | Company is acquired |
| What You Get | Some/all unvested equity vests immediately |
| Who Gets It | Usually executives, sometimes key employees |
Example: You have 50,000 unvested options. The company is acquired. With 100% single-trigger acceleration, all 50,000 vest immediately.
Double-Trigger Acceleration
| What It Is | Vesting accelerates on two events |
|---|---|
| Triggers | (1) Company acquired AND (2) You're terminated |
| What You Get | Some/all unvested equity vests |
| Who Gets It | More commonly offered than single-trigger |
Example: The company is acquired (trigger 1). You continue working. Six months later, you're laid off (trigger 2). Your remaining unvested equity accelerates.
Double-trigger is more common because it protects employees without creating perverse incentives (single-trigger can encourage people to push for acquisition and leave immediately).
Negotiating Acceleration
| Factor | Negotiability |
|---|---|
| Senior/executive role | Often negotiable |
| Standard IC offer | Rarely negotiable |
| Acquisition likely | More valuable |
| Early-stage | More negotiable |
If you're joining a company that might be acquired, acceleration clauses matter significantly. Ask about them.
What Happens When You Leave
Understanding post-termination rules is critical.
Options vs. RSUs
| Equity Type | At Departure |
|---|---|
| Stock options | You have a window to exercise vested options |
| RSUs | Vested shares are yours; unvested are forfeited |
RSUs are simpler: what's vested is yours, period. Options require decisions.
The Exercise Window
When you leave a company with stock options, you typically have a limited time to exercise (buy) your vested options.
| Window Length | Common At |
|---|---|
| 90 days | Traditional, most common |
| 1 year | Some progressive companies |
| 5-10 years | Forward-thinking companies |
| Until expiration | Rare, most employee-friendly |
The 90-day window is brutal. If you have vested options worth $200,000 with a $50,000 exercise cost, you need $50,000 cash within 90 days of leaving—plus potentially significant tax on the spread.
Exercise Window Example
| Scenario | 90-Day Window | 10-Year Window |
|---|---|---|
| Vested options | 50,000 | 50,000 |
| Strike price | $1 | $1 |
| Current FMV | $5 | $5 |
| Exercise cost | $50,000 | $50,000 |
| Time to decide | 90 days | 10 years |
| If you can't afford it | Forfeit options | Wait for liquidity |
The extended exercise window is increasingly common at progressive startups. It's worth asking about—and negotiating if possible.
Tax Implications at Exercise
| Option Type | Tax at Exercise |
|---|---|
| ISOs (Incentive Stock Options) | AMT on spread |
| NSOs (Non-Qualified Stock Options) | Ordinary income on spread |
This gets complicated quickly. If you're facing an exercise decision, consult a tax advisor.
Questions to Ask About Vesting
When evaluating an offer:
| Question | Why It Matters |
|---|---|
| What's the vesting schedule? | Confirm standard vs. unusual |
| What's the cliff length? | 1 year is standard; shorter is better |
| What's the post-termination exercise window? | 90 days is challenging; longer is better |
| Are there any acceleration clauses? | Matters if acquisition is possible |
| When does vesting start? | Should be first day; confirm |
| How does vesting work for RSUs vs. options? | Different mechanics |
Negotiating Vesting Terms
| Term | Negotiability | Typical Ask |
|---|---|---|
| Total equity amount | Medium-High | 20-50% more |
| Vesting period | Low | 3 years instead of 4 |
| Cliff length | Low-Medium | 6 months instead of 12 |
| Exercise window | Medium | 5-10 years instead of 90 days |
| Acceleration | Medium (senior only) | Double-trigger at minimum |
| Vesting start date | Low | Retroactive to start |
The exercise window is often the easiest term to negotiate because it costs the company nothing but matters significantly to you.
Red Flags
| Red Flag | Concern |
|---|---|
| Non-standard cliff (>1 year) | Unusually employee-unfavorable |
| Very long vesting (>4 years) | Extended commitment required |
| 30-day exercise window | Extremely aggressive |
| No written equity agreement | Verbal promises are worthless |
| Vague about fully diluted shares | Can't calculate percentage |
The engineer who left at month 11 without understanding the cliff? Expensive lesson. The equity he forfeited would have been worth $180,000 at the company's eventual acquisition.
Understanding vesting isn't optional. The cliff, the schedule, and the exercise window directly determine whether your equity is real compensation or an empty promise.
References
[^1]: SmithSpektrum offer negotiation and equity advisory data, 2020-2026. [^2]: Carta, "Equity 101," equity education resources. [^3]: Index Ventures, "The Option Plan Guide," 2024. [^4]: First Round Review, "Understanding Startup Equity," 2023.
Need help understanding an equity offer? Contact SmithSpektrum for confidential offer analysis.
Author: Irvan Smith, Founder & Managing Director at SmithSpektrum