How equity fits into the package
For embedded engineers, Tesla and SpaceX embedded roles carry long-vesting PSUs tied to milestones, which delays and lumps tax recognition. Base salary covers living expenses; equity carries the upside and the tax complexity.
What usually goes wrong
The most common planning mistake: treating the 22% supplemental withholding on RSU vestings as "my taxes are handled." For any embedded engineer past the senior bracket, actual marginal rates are higher. The shortfall surfaces in April.
Planning checklist
- Model every vest against your actual marginal rate. Use the RSU vesting calculator.
- Make quarterly estimated payments if the under-withholding exceeds safe-harbor thresholds.
- Decide on a sell-at-vest policy. Holding concentrated employer stock creates risk that compounds.
- If you have ISOs, run the AMT tripwire before exercising.
- Match with an advisor when a vest crosses $500k or an exercise crosses $200k of bargain element.