One of the financial advantages of locum tenens work is the ability to deduct certain travel expenses when you take a temporary assignment away from home. Hotel bills, airfare, mileage, and meals can add up quickly, so these deductions may be substantial.

But there is an important rule that locums physicians should understand:

Once an assignment is expected to last more than one year, the tax treatment changes significantly.

When you’re a physician, consultant, or small business owner with income that crosses state lines, the rules start to feel like an interstate turf war.

Each state wants its cut — and unfortunately, they’re not always good at sharing.