What Montana residents actually pay
Montana taxes ordinary income at a top marginal rate of 5.9%. 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.
Partial capital-gains credit.
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 Montana, layer on 5.9% 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 Montana tax RSU income the same as wages?
- Yes. Montana treats RSU ordinary income as wages, taxable at the state's top marginal rate of 5.9%. 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 Montana?
- Montana 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 Montana 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 Montana move, expect the old state to tax the portion of each tranche attributable to workdays earned there. Montana taxes the remainder.
- Can I reduce Montana taxes by timing my RSU sales?
- Montana gives preferential treatment to long-term capital gains. Holding RSU shares 12+ months past vest can produce both federal and state savings. Weigh concentration risk before using this as a reason to hold.
Related
- ISO exercises and AMT — Montana
- Capital gains tax — Montana
- QSBS — Montana
- Moving to or from Montana with unvested equity: trailing nexus rules — Montana
- RSU vesting schedules — Montana
- ESPP taxation — Montana
- NSO exercises and state tax — Montana
- 401(k) and retirement accounts — Montana
- Leaving Montana: how to cleanly break residency before a liquidity event — Montana
- Montana equity-comp overview