What Mississippi residents actually pay
Mississippi 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.
Traditional 401(k) in Mississippi
A pre-tax 401(k) contribution reduces both federal and Mississippi taxable income today. At the top bracket, every $1,000 contributed saves 39.4 cents on the dollar (federal 35% + state 4.4%). At retirement, withdrawals are taxed at your then-current bracket.
Roth 401(k) breakeven
Roth 401(k) contributions are taxed at today's rates; withdrawals are tax-free. The Roth choice beats traditional when your retirement bracket is higher than your contribution bracket. For equity earners in high-income years, traditional is usually right during big RSU years and Roth is right during low-income transition years.
Mega-backdoor Roth
After-tax 401(k) contributions above the standard $23,500 limit can be converted to Roth in plans that allow it. For high earners in Mississippi, this is the largest tax-advantaged bucket available after the primary 401(k) and IRA caps. Check whether your plan allows after-tax contributions and in-plan Roth conversions.
Frequently asked
- Does Mississippi tax RSU income the same as wages?
- Yes. Mississippi 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 Mississippi?
- Mississippi 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 Mississippi 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 Mississippi move, expect the old state to tax the portion of each tranche attributable to workdays earned there. Mississippi taxes the remainder.
- Can I reduce Mississippi taxes by timing my RSU sales?
- Mississippi 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
- RSU taxes — Mississippi
- ISO exercises and AMT — Mississippi
- Capital gains tax — Mississippi
- QSBS — Mississippi
- Moving to or from Mississippi with unvested equity: trailing nexus rules — Mississippi
- RSU vesting schedules — Mississippi
- ESPP taxation — Mississippi
- NSO exercises and state tax — Mississippi
- Leaving Mississippi: how to cleanly break residency before a liquidity event — Mississippi
- Mississippi equity-comp overview