Google Quarterly RSUs: Withholding Gap Planning
A case study on monthly/quarterly vesting: how the gap compounds and how to fix it before Q4.
Last updated: January 2026
Google-style RSU vesting structure
Many Google RSU (GSU) schedules vest monthly and can be front-loaded. (Actual schedules vary by level/cohort — always confirm grant docs.)
| Year | Typical vesting % | Frequency |
|---|---|---|
| Year 1 | 33% | Monthly (≈2.75%/month) |
| Year 2 | 33% | Monthly (≈2.75%/month) |
| Year 3 | 22% | Monthly (≈1.83%/month) |
| Year 4 | 12% | Monthly (≈1.0%/month) |
Case study: Google L5 engineer
| Factor | Details |
|---|---|
| Base salary | $220,000 |
| Annual RSU value | $150,000 |
| Year 1 vesting (33%) | ~$50,000 |
| Year 2 vesting + refreshers | ~$80,000 |
| Filing status | Married Filing Jointly |
| State | California |
The withholding gap problem
With monthly vesting, the gap can quietly accumulate throughout the year. By December, clients can be under-withheld by $15K–$20K (or more) without realizing it.
| Item | Withholding | Actual tax | Gap |
|---|---|---|---|
| Federal on $80K RSU income | 22% = $17,600 | 35% = $28,000 | $10,400 short |
| CA state gap (illustrative) | 10.23% | 11.3% | ~$850 short |
| Total gap (illustrative) | — | — | $11,250+ |
Monthly vesting turns one big surprise into 12 smaller ones — which still add up. If the client doesn’t adjust during the year, they may owe a large April balance and risk underpayment penalties.
Solutions for Google clients
- Increase sell-to-cover: set federal withholding closer to the true marginal bracket.
- Additional W-4 withholding:compute annual gap and divide by remaining pay periods (W-4 Step 4(c)).
- Quarterly estimated payments:simplest for clients who want separation from payroll.
- Year-end tax harvest: sell additional vested shares beyond sell-to-cover in Q4.
| Quarter | Due date | Example payment |
|---|---|---|
| Q1 | April 15 | $2,800 |
| Q2 | June 15 | $2,800 |
| Q3 | September 15 | $2,800 |
| Q4 | January 15 | $2,800 |
Cost basis tracking reminders
- Monthly vesting creates 12+ tax lots per year.
- Brokers may show $0/blank basis on 1099-B; use FMV at vest.
- Use specific identification when selling (if supported).
- Report basis adjustments on Form 8949 to avoid double taxation.
Schedule a “Q4 tax check-in” call in October. Review YTD vesting, withholding, and decide whether the client should make estimated payments or increase withholding before year-end.