Moving from South Dakota to Northern Mariana Islands: Residency, Taxes, and What to Prove

In South Dakota

South Dakota is a genuine, common tax-home domicile choice for travel nurses because it imposes no income tax and its driver's license rule (one overnight stay plus a mailing address) is achievable even for someone who is only in the state briefly between assignments. As with any tax-home claim, the IRS still requires the nurse to actually maintain and periodically return to a real home base, not just a mailing address, or the tax-free housing stipend can be reclassified as taxable wages; a South Dakota mail-forwarding address with no genuine pattern of returning to the state is a weaker tax-home claim than one paired with real, if infrequent, physical presence.

In Northern Mariana Islands

The CNMI is not a travel-nurse assignment market comparable to the 50 states; the Commonwealth Health Center on Saipan is the territory's main hospital and does not typically draw mainland travel-nursing agency placements at scale, so this persona has limited applicability here.

In South Dakota

South Dakota has no major professional sports franchise. South Dakota itself never taxes any athlete's income regardless of domicile, but a South Dakota-domiciled athlete still owes nonresident jock tax in every state with an income tax where they play, based on duty-day apportionment; South Dakota's appeal as a domicile is that it eliminates the home-state slice of that calculation entirely.

In Northern Mariana Islands

No major U.S. professional sports franchise is based in the CNMI, and there is no jock-tax apportionment regime specific to the territory.

In South Dakota

South Dakota is less commonly the destination for classic snowbird arrangements (that role is dominated by Florida, Arizona, and Texas) and more commonly the domicile-of-record for people who are mobile year-round, especially full-time RVers who don't have a fixed second home anywhere. Because South Dakota imposes no exit test of its own on people leaving and no entry test creating South Dakota tax liability, the entire audit risk in a South Dakota domicile arrangement sits with whatever state the person actually spends significant time in, most often assessed under that state's own statutory residency or day-count rules.

In Northern Mariana Islands

Publication 570's own illustrative example is a snowbird-adjacent CNMI fact pattern: a retired couple who own a condominium in the CNMI and a house in Maine, spend 120 days a year in Maine near their grown children, and take an 85-day vacation to Europe and Asia. Because their only income was pension, dividends, interest, and Social Security (no U.S. earned income), the 30-day travel-day rule let their 160 actual CNMI days count as 190 presence days, satisfying the presence test despite the significant Maine ties, though the example does not resolve whether they'd separately clear the tax home and closer connection tests.

In South Dakota

There is no convenience-of-the-employer rule to worry about because South Dakota has no income tax to apply one under. A remote worker who establishes genuine South Dakota domicile, meaning an actual driver's license, mailing address, and a credible pattern of connection to the state, owes $0 South Dakota tax regardless of where their employer is headquartered, which has made South Dakota a popular domicile choice for remote workers leaving California, New York, and other high-tax states, alongside Texas and Florida.

In Northern Mariana Islands

The CNMI has no convenience-of-the-employer rule of its own, but a mainland employer's own state convenience rule can still reach a CNMI-based remote worker's wages if the employer continues to treat them as mainland-sourced. As with Guam, most mainland payroll systems are not set up to withhold correctly for the CNMI's Chapter 2/Chapter 7 system, which is a practical obstacle for new remote-worker residents.

In South Dakota

South Dakota follows the federal Servicemembers Civil Relief Act and Military Spouses Residency Relief Act. Because South Dakota has no income tax, service members and spouses who elect South Dakota domicile under MSRRA simply owe no state tax on military pay or spousal income. Ellsworth Air Force Base near Rapid City is the state's major installation and a common source of South Dakota domicile elections among service members and their spouses.

In Northern Mariana Islands

The CNMI follows the federal Servicemembers Civil Relief Act (SCRA) and Military Spouses Residency Relief Act (MSRRA): a servicemember's home-of-record does not change solely because of orders stationing them in the CNMI, and a civilian spouse can elect to keep the servicemember's tax residence. A servicemember who qualified as a bona fide CNMI resident in an earlier year does not lose that status due to an absence in compliance with military orders, but being stationed there under orders alone does not create bona fide residency.

In South Dakota

Federal law (49 U.S.C. §40116) limits taxation of air carrier employees to their state of residence and any state where they earn more than 50% of pay. South Dakota is not a major airline crew base, but since South Dakota itself never taxes income, South Dakota-domiciled crew simply owe $0 South Dakota tax and rely on the federal rule to limit exposure to whichever state actually taxes them.

In Northern Mariana Islands

Saipan International Airport has more limited scheduled international service than Guam. The federal carve-out at 49 U.S.C. section 40116 for air carrier employees would apply the same way it does across the other territories if relevant, but the CNMI is not a significant crew base.