What Colorado residents actually pay
Colorado taxes ordinary income at a top marginal rate of 4.4%. RSU settlement value, NSO exercise spread, and ESPP discount income all count as ordinary wages for this purpose and flow through the state's normal brackets.
Flat 4.4% state rate. Denver has become a meaningful secondary tech hub.
Withholding gap
Federal supplemental-wage withholding on RSU vesting is flat — 22%, rising to 37% once year-to-date supplemental wages exceed $1M. If your actual marginal rate is higher, the shortfall shows up at filing. In Colorado, layer on 4.4% at the top and model what you'll owe before year-end.
Sourcing when you move
If you earned part of a vesting tranche while in a different state, most high-tax states (California, New York, Massachusetts) use workday allocation between grant and vest. Your payroll will likely withhold only for your current state, so a manual true-up at filing is the rule, not the exception.
Frequently asked
- Does Colorado tax RSU income the same as wages?
- Yes. Colorado treats RSU ordinary income as wages, taxable at the state's top marginal rate of 4.4%. Supplemental-wage federal withholding (22%, or 37% above $1M YTD) does not adjust for state withholding, so you often owe extra at filing.
- What happens if I exercise ISOs while living in Colorado?
- Colorado does not run a separate state AMT, so only federal AMT applies. You still need to model the bargain element carefully if you plan a cashless exercise-and-sell.
- I moved to Colorado from another state. Who taxes my vesting RSUs?
- Most high-tax states (CA, NY, MA) source RSU ordinary income to workdays between grant and vest. If your grant pre-dates your Colorado move, expect the old state to tax the portion of each tranche attributable to workdays earned there. Colorado taxes the remainder.
- Can I reduce Colorado taxes by timing my RSU sales?
- Colorado taxes long-term capital gains at the same rate as ordinary income, so timing alone does not produce a state savings — only federal. Holding for 12 months still halves the federal rate on gains above basis.
Related
- ISO exercises and AMT — Colorado
- Capital gains tax — Colorado
- QSBS — Colorado
- Moving to or from Colorado with unvested equity: trailing nexus rules — Colorado
- RSU vesting schedules — Colorado
- ESPP taxation — Colorado
- NSO exercises and state tax — Colorado
- 401(k) and retirement accounts — Colorado
- Leaving Colorado: how to cleanly break residency before a liquidity event — Colorado
- Colorado equity-comp overview