Locum Tenens Tax Guide: Deductions, Multi-State Filing, and Entity Setup | SDO CPA

Locum Tenens Tax Guide: What Traveling Physicians Need to Know

Locum tenens physicians face the most complex tax situations of any physician type. High income, self-employment taxes, multi-state filing, and travel deductions that can go wrong fast — it’s a lot to manage on top of a demanding clinical schedule.

The core issues come down to three things: you’re a self-employment taxpayer responsible for taxes no employer is withholding, you likely owe income taxes in multiple states, and your travel deductions only work if you have a proper “tax home” under IRS rules. Get any of these wrong and the cost can be significant.

This locum tenens tax guide covers what you need to know — self-employment tax rates, the tax home rules that determine whether your travel is even deductible, multi-state filing requirements, and strategies like S-Corp elections that can reduce your tax bill.

How are locum tenens physicians taxed?

Locum tenens physicians typically receive 1099-NEC income, making them self-employed. That means self-employment tax (15.3% on net earnings up to the Social Security wage base, plus 2.9% Medicare on everything above), quarterly estimated payments, and filing returns in every state where you worked. Travel expenses, health insurance, and retirement contributions may be deductible. An S-Corp election can potentially cut your self-employment tax bill by $10,000–$25,000+ annually depending on income and salary structure.

Key Takeaways

• Locum tenens income is 1099 self-employment income — you owe self-employment tax plus federal and state income tax with no employer withholding
• Multi-state filing is required — you must file a non-resident state return in every state where you earned income (if that state has an income tax)
• Travel deductions depend on your “tax home” — if you have no regular place of business, the IRS may disallow all travel deductions
• Quarterly estimated taxes are required — missing payments can result in underpayment penalties from both the IRS and your home state
• An S-Corp election can reduce self-employment taxes on income above your reasonable salary, potentially saving tens of thousands annually
• Retirement contributions are available and substantial — a solo 401(k) or SEP-IRA can shelter a meaningful portion of your locum income from current-year taxes

The Self-Employment Tax Problem for Locum Physicians

When a hospital pays you through a locum agency and you receive a 1099-NEC, you’re self-employed in the eyes of the IRS. That comes with a tax most employed physicians never think about: self-employment (SE) tax.

SE tax is 15.3% on your net self-employment earnings up to the Social Security wage base — $184,500 in 2026. Above that threshold, the Social Security portion (12.4%) drops off, but the Medicare portion (2.9%) continues on all net earnings. On top of that, if your earned income exceeds $200,000 (single) or $250,000 (married filing jointly), an additional 0.9% Medicare surtax applies.

A physician earning $300,000 in locum income could owe up to approximately $26,965 in SE taxes before accounting for any deductions. That’s not income tax — that’s just the SE tax layer on top of your ordinary income tax rate.

One offset does exist: you can deduct half of your SE tax from your gross income. This is an above-the-line deduction, meaning it reduces your adjusted gross income regardless of whether you itemize. It doesn’t eliminate the SE tax burden, but it does reduce your taxable income.

For context, a W-2 physician splits this 15.3% with their employer — each side pays 7.65%. As a locum tenens physician, you pay both sides. That gap is exactly why entity structures like S-Corps are worth analyzing at higher income levels.

For more on physician tax planning strategies, SDO CPA works with physicians across practice types, including independent contractors. See also our independent contractor tax guide for a broader overview of 1099 income tax rules.

Your Tax Home and Why It Determines Everything

This is the most misunderstood area of locum tenens taxes — and the one where incorrect assumptions cost physicians the most.

The IRS defines your “tax home” as your regular or principal place of business, not where your family lives or where your driver’s license says you’re from. For locum physicians, this distinction is critical because travel expenses are only deductible when you’re traveling away from your tax home.

Here’s how it plays out in practice:

If you have a regular home base: A physician who maintains a part-time or moonlighting position at a hospital in Dallas — even a few shifts a month — can establish Dallas as their tax home. When they travel to Phoenix or Chicago for locum assignments, those travel costs may be deductible because they’re away from their tax home.

If you’re a permanent locum with no regular base: A physician who closes out all local work and travels exclusively from assignment to assignment has no regular place of business. The IRS may determine this physician has no tax home at all. When you have no tax home, there is no “away from home” travel — and the deductions disappear entirely.

The stakes here are real. An IRS challenge to your travel deductions could eliminate tens of thousands in claimed expenses. The documentation burden also falls entirely on you: assignment locations, dates worked, where you slept, distance from your home city, and whether you returned home between assignments.

How to establish a tax home as a locum: – Maintain a regular moonlighting or part-time position in your home city – Return home regularly between assignments (not just occasionally) – Document your home base with rent/mortgage, utilities, and local professional activities – Keep detailed records of every assignment — location, start date, end date, and travel costs

This is one area where an incorrect assumption is very expensive. Confirm your tax home status before claiming travel deductions. State-specific rules should be verified with a CPA familiar with multi-state locum situations.

Multi-State Tax Filing for Traveling Physicians

If you worked in three states last year, you likely owe income tax in three states — plus your home state.

The rule is straightforward: you must file a non-resident income tax return in every state where you earned income, as long as that state has an income tax and your income there exceeded the state’s de minimis threshold. Income is allocated to each state based on where you physically worked the days you earned it.

Your home state return is filed as a resident return. Most states provide a tax credit for income taxes paid to other states, which prevents true double taxation — but it doesn’t eliminate the requirement to file in multiple states. It also doesn’t prevent your home state from taxing income earned elsewhere (the credit reduces, not eliminates, the home state tax on that income).

States with no personal income tax — no state return required if you only worked there:

Your locum agency’s annual 1099 may not break down income by state. Request a detailed earnings statement showing income earned in each state. Some agencies provide this; others require you to reconstruct it from your assignment records and pay stubs. Keep your own records throughout the year — don’t wait until tax time to figure out where you worked.

For a deeper look at how multi-state income allocation works, see our guide on multi-state tax filing.

Deductions Available to Locum Tenens Physicians

As a self-employed physician, your business expenses reduce your net self-employment income — which reduces both your income tax and your SE tax. That double benefit makes deductions more valuable to a locum than to a W-2 employee.

Travel (if tax home is established) Flights, hotel, and rental car costs to and from assignment locations may be deductible if you’re traveling away from your tax home. Keep every receipt and document the business purpose.

Meals 50% of meal costs while traveling away from home overnight. The IRS per diem rates are an alternative to tracking actual receipts.

State medical licensing fees If you practice in multiple states, each license fee is deductible as a business expense. This adds up fast for physicians with licenses in five or six states.

Continuing medical education (CME) CME required for licensure or maintaining your professional skills is deductible. Travel to CME conferences may also qualify if the primary purpose is education.

Malpractice insurance Tail coverage and occurrence-based malpractice premiums are deductible business expenses — one of the larger recurring costs for many locum physicians.

Professional dues AMA membership, specialty organization fees, and similar dues are deductible.

Home office If you have a dedicated space used exclusively for managing your locum practice — scheduling, billing follow-up, CME research — it may qualify for the home office deduction. The space must be used regularly and exclusively for business.

Retirement contributions A solo 401(k) allows contributions of up to $72,000 in 2026 (combined employee + employer contributions if under age 50). A SEP-IRA allows up to 25% of net self-employment income. These contributions reduce your taxable income in the current year.

Health insurance premiums Self-employed physicians can deduct health insurance premiums paid for themselves, a spouse, and dependents — above the line, directly reducing AGI.

See our full guide on medical practice tax deductions for a complete list with documentation requirements.

S-Corp for Locum Tenens Physicians

For locum physicians earning $200,000 or more annually in 1099 income, an S-Corp election is worth a serious look. The structure can reduce the SE tax burden by splitting income between a salary (subject to SE tax) and distributions (not subject to SE tax).

Here’s how it works: you form a professional limited liability company (PLLC) or professional corporation (PC) in your home state, file IRS Form 2553 to elect S-Corp tax treatment, and pay yourself a reasonable salary based on market rates for your specialty. Net income above the salary can be distributed to you as a shareholder distribution — not subject to the 15.3% / 2.9% SE tax.

The potential tax savings vary based on your income level and what the IRS considers a “reasonable salary” for your specialty. A physician earning $350,000 who takes a $180,000 salary could potentially reduce SE taxes on the remaining $170,000. At 2.9% Medicare (the portion that continues above the SS wage base), that’s roughly $4,930 in Medicare tax savings — plus the 12.4% SS savings on income below the wage base.

One important step before forming an entity: confirm with your locum agency whether they’ll contract with your PLLC or PC instead of you personally. Some agencies work with physician entities; others require the contract to be with an individual. This needs to be confirmed before you set up the structure.

Additional considerations: – The S-Corp must pay you a reasonable salary based on specialty and regional benchmarks — the IRS scrutinizes low salaries in S-Corp structures – You’ll need to run payroll, file quarterly payroll returns, and file a separate S-Corp tax return (Form 1120-S) – Compliance costs (payroll processing, CPA fees for the entity return) offset some savings — the math works best at higher income levels

Learn more about S-Corp for doctors and the PLLC vs PC for doctors decision.

Quarterly Estimated Taxes for Locums

No employer is withholding federal or state taxes from your 1099 income. That responsibility falls on you, and the IRS requires you to pay as you earn — not in one lump sum at tax time.

Quarterly estimated tax payments are due on: – April 15 (Q1) – June 15 (Q2) – September 15 (Q3) – January 15 (Q4 of prior year)

To avoid an underpayment penalty, you generally need to pay either 90% of your current year tax liability or 100% of last year’s tax liability — whichever is smaller. If your prior year adjusted gross income exceeded $150,000, the safe harbor is 110% of last year’s tax.

First-year locum physicians face an extra challenge. If your prior year was W-2 employment, your prior year tax was largely handled by employer withholding. You may not be able to rely on that safe harbor because your prior year tax reflected a very different income situation. In that case, estimate your current year carefully and pay accordingly.

Pay federal estimated taxes through IRS Direct Pay or EFTPS (Electronic Federal Tax Payment System). Most states with income tax have their own estimated payment systems — check your home state’s department of revenue for the payment portal and due dates.

Frequently Asked Questions

Do I need to form a business entity to work locum tenens?

No. Most locum physicians work as sole proprietors and receive 1099-NEC income directly. Forming a PLLC or PC with S-Corp treatment is a tax strategy, not a requirement. Many physicians start as sole proprietors and form an entity once income is high enough to justify the compliance costs — typically $200,000+ in annual locum income.

How do I prove my travel expenses are deductible?

Keep receipts for every flight, hotel, and rental car. Document the assignment location, dates worked, and that you were away from your tax home overnight. A mileage log helps for any driving. A calendar showing your assignment schedule alongside your home base activity (moonlighting shifts, local medical activities) supports the tax home argument if challenged.

What happens if I don’t file in a state where I worked?

States do share data. If your locum agency reports your income to a state where you worked, that state can assess tax, penalties, and interest — sometimes years later. A few thousand dollars in unfiled state taxes can become significantly more after penalties. File in every state where you earned income above that state’s threshold.

Can my locum agency pay my S-Corp instead of me personally?

Some agencies will, some won’t. This needs to be confirmed before you set up the entity. Ask directly whether they’ll execute the contract with your PLLC or PC. If the agency requires an individual contract, the S-Corp may not be viable for that assignment — though some physicians maintain an S-Corp for some assignments and work directly for others.

Do I owe self-employment tax on all my locum income?

SE tax applies to net self-employment income — your gross 1099 income minus your deductible business expenses. Deductions for travel, licensing fees, malpractice insurance, and retirement contributions reduce your net earnings before SE tax is calculated. The deductible half of SE tax also reduces your AGI, though it doesn’t reduce your SE tax itself.

What’s the difference between a W-2 and 1099 locum position?

A W-2 locum position means the agency treats you as an employee. They withhold federal and state taxes, pay the employer half of Social Security and Medicare taxes (7.65%), and you don’t owe SE tax. A 1099 position makes you self-employed — you handle all tax payments, owe both halves of SE tax, but gain access to business deductions. The net income difference between a W-2 and equivalent 1099 offer depends on the income level and what expenses you can deduct.

Get Your Locum Tenens Tax Strategy Right

Locum tenens taxes involve more moving parts than almost any other physician tax situation: self-employment tax, multi-state filings, the tax home question, quarterly payments, and potential entity structures. Getting the analysis right in year one sets you up for consistent tax savings going forward.

SDO CPA analyzes locum tenens tax situations, including multi-state filing strategy and S-Corp feasibility analysis. If you’re a traveling physician looking to understand your full tax picture, schedule a consultation.

This article is for general informational purposes. Tax rules for locum tenens physicians are complex and state-specific rules change. Consult a CPA with experience in physician taxation before making decisions about entity structure, travel deductions, or multi-state filing strategy.

External resources: – IRS Publication 463 — Travel, Gift, and Car Expenses – IRS Self-Employment Tax Overview