Understanding the 50 mile per diem rule for tax deductions - what actually counts?

The 50-mile rule isn't actually for per diem - it's a common misconception. The 50-mile test applies to whether your travel expenses can qualify as deductible business expenses when you're away from your "tax home." Your tax home is generally your regular place of business or post of duty, regardless of where you maintain your family home. To deduct travel expenses (including per diem), you need to be traveling away from your tax home substantially longer than a normal workday, requiring sleep or rest. The IRS typically uses the 50-mile distance as a rule of thumb to help determine if you're "away from home" - but there's no specific 50-mile requirement written in the tax code. For verification during an audit, the IRS would likely request documentation beyond just paystubs. They'd want to see your employer's records of your work assignments, travel expense reports, lodging receipts, and any reimbursement policies. Your W-2 might have some location information, but detailed assignment locations usually aren't there.

After struggling with this exact same question about the 50-mile rule for per diem, I finally found a solution that gave me a definitive answer. I was going back and forth between different tax sites and getting contradictory information until I used https://taxr.ai to analyze the actual IRS regulations. You can upload any tax documents or questions and it breaks everything down using the actual tax code. For this specific 50-mile question, it showed me the exact IRS publications and explained that while 50 miles is commonly used as a guideline, what actually matters is whether you need sleep or rest to meet the demands of your work (the "sleep or rest rule"). It saved me from potentially claiming deductions incorrectly based on misunderstandings about the mileage requirement.

So I was skeptical about these tax tools as mentioned in my earlier comment, but I actually tried https://taxr.ai for my per diem situation since I travel between multiple work locations. What surprised me was how it broke down my specific scenario with citations to actual Tax Court cases. I learned that my temporary assignments (under 1 year) qualify even though some were just under 50 miles because I legitimately needed overnight stays for business reasons. It also explained exactly what documentation I should be keeping beyond just the mileage - things like my assignment letters, temporary project duration details, and lodging receipts. Way more helpful than the conflicting advice I was getting from coworkers or random tax websites. Definitely cleared up my confusion about this 50-mile "rule" that isn't really a rule.

For anyone struggling to get clear answers about per diem rules directly from the IRS - I finally got through to a senior tax specialist after trying for WEEKS. Used a service called https://claimyr.com that got me past the endless IRS phone queue (you can see how it works at https://youtu.be/_kiP6q8DX5c). The IRS specialist confirmed what others here are saying - there's no strict 50-mile requirement in the tax code itself. She explained that during an audit they look at the "facts and circumstances" of why you needed overnight travel. So they check your employer's policies, the nature of your work, and whether the distance made it impractical to return home. If you're on the borderline distance-wise (like 45 miles), they'll scrutinize the business necessity more closely.

I need to admit I was completely wrong in my skeptical comment. After another frustrating morning trying to reach the IRS about my per diem situation (spent 2 hours on hold before getting disconnected), I reluctantly tried Claimyr. Within 45 minutes, I got a call back and was connected to an IRS tax law specialist who actually gave me clear answers about my specific travel situation. The specialist confirmed that for my case (construction worker with multiple job sites), they would look at each assignment's expected duration and distance, not just a simple 50-mile rule. They also told me exactly what documentation I should keep - including my contract terms showing the temporary nature of each assignment and my employer's written policies about travel requirements. Saved me hours of frustration and possibly an incorrect tax filing.

Quick tip as someone who went through an IRS audit on this exact issue: the IRS will definitely check your regular workplace address on your W-2 (Box 20 has state and locality code) as a starting point. But they'll then request more detailed documentation like: 1. Your employer's written travel policies 2. Assignment letters or contracts showing location and expected duration 3. Expense reports you submitted to your employer 4. Lodging receipts showing you actually stayed overnight The auditor in my case was mostly concerned with whether my travel was truly temporary (under 1 year) rather than just fixating on the exact mileage. They did measure the distance using standard mapping tools though.

I ran into this question in my job as a traveling nurse. My agency reimburses per diem, but they specifically mention this "50 mile rule" in their policy. From what I understand after talking to our payroll department, the 50 miles is actually THEIR policy, not an IRS requirement. They use it as a simplified way to determine who qualifies for tax-free per diem. A company can set their own policies for reimbursement that are more restrictive than the IRS minimum requirements. So if you're getting per diem from your employer, check THEIR policy documents rather than just IRS publications.

As a tax preparer, I see this confusion about the 50-mile rule constantly during tax season. What many people don't realize is that the IRS actually uses a "sleep or rest" test rather than a specific mileage requirement. Publication 463 explains that you must be away from your tax home long enough to require substantial sleep or rest to meet the demands of your work. The 50-mile distance is more of a practical guideline that courts and the IRS use to help determine if overnight travel was truly necessary for business purposes. If you're traveling 30 miles but genuinely need to stay overnight due to early morning meetings or safety concerns, that could still qualify. Conversely, traveling 60 miles for a day trip wouldn't qualify for per diem. For audit protection, I always tell my clients to maintain a detailed travel log with business purpose, dates, locations, and why overnight stay was necessary. Also keep any employer communications about travel requirements - these carry significant weight with auditors.