Locum and 1099 tax structure for anesthesiologists: when an S-corp actually saves money

Locum CRNAs and anesthesiologists with 1099 income often miss the entity-structure conversation. Here’s when an S-corp pays off, when it doesn’t, and how to model it.

Most of us finish residency with world-class clinical training but a kindergarten-level understanding of business and tax structure. We take the first 1099 contract a staffing group offers, cash the checks, and get a brutal surprise when the first quarterly estimated tax payment is due. The shift from a W-2 employee to an independent contractor is a fundamental change in your financial identity. You are no longer just a clinician; you are a business. And the single most impactful decision you can make for that business is choosing the right legal and tax entity.

This isn’t just about saving a few dollars; it’s about tens of thousands in tax savings annually, unlocking powerful retirement strategies, and protecting your personal assets. We’ll walk through the specific, high-yield strategies that apply directly to our specialty—from the S-corp election that slashes your self-employment tax bill to the travel deduction rules that can make or break a locum career. For more resources tailored to our field, you can also explore the anesthesiology free tools hub for other guides and checklists.

The S-Corp Strategy: Slashing Your Self-Employment Tax Bill

When you work as a 1099 independent contractor, you’re on the hook for both the employee and employer halves of FICA taxes (Social Security and Medicare). This is called the Self-Employment (SE) tax, and it’s a steep 15.3% on your net business income up to the Social Security wage base ($168,600 for 2024), plus 2.9% on all income above that. For a physician earning $500,000, this is a significant tax drag right off the top.

This is where the S-corporation election becomes a powerful tool. By forming an LLC and electing to have it taxed as an S-corp, you can change how your income is characterized. Instead of all your profit being subject to SE tax, you pay yourself a “reasonable salary” as a W-2 employee of your own corporation. The remaining profit is then paid out to you as a shareholder distribution, which is not subject to SE tax.

Here’s a concrete example:

• Scenario A (Sole Proprietor): You net $500,000. The entire amount is subject to SE tax. You’ll pay roughly $22,000 in SE taxes.
• Scenario B (S-Corp): You net $500,000. You pay yourself a reasonable W-2 salary of $250,000. Only this portion is subject to FICA taxes (paid by you and your S-corp). The remaining $250,000 is taken as a distribution, which is exempt from FICA/SE tax. The savings on that $250,000 distribution amount to thousands of dollars in Medicare tax alone.

The How-To Sequence:

1. Form a legal entity in your state, typically a single-member LLC.
2. File IRS Form 2553, “Election by a Small Business Corporation,” to have your LLC taxed as an S-corp. This must be done within 75 days of the start of your tax year.
3. Open a dedicated business bank account. All 1099 income goes in, all business expenses go out.
4. Set up a payroll service to pay your W-2 salary and handle withholdings.
5. Pay yourself the remaining profit as distributions.

The Trap to Avoid: The IRS requires your W-2 salary to be “reasonable” for the services you provide. You can’t pay yourself a $50,000 salary on $500,000 of income. Defensibility comes from documenting market-rate compensation for anesthesiologists in your region with similar experience. Lowballing your salary is the fastest way to trigger an audit and have the IRS reclassify your distributions as wages, hitting you with back taxes and penalties. Getting this structure right often requires professional guidance, which is where a physician CPA referral can connect you with an expert who understands medical practice finance.

The Locum Tenens Tax-Home Trap: A Costly Mistake

One of the biggest financial perks of locum tenens work is the ability to deduct travel-related expenses: flights, lodging, rental cars, and 50% of meals. These deductions can easily be worth $30,000-$50,000 a year. But they all hinge on one critical, and often misunderstood, IRS concept: the “tax home.”

Your tax home is your regular place of business or post of duty, regardless of where your family lives. To deduct travel expenses, you must be traveling away from this tax home for business purposes. Most of us assume our family residence is our tax home, but the IRS sees it differently.

The Trap: Becoming “Itinerant”

If you don’t have a regular place of business and you continuously move from one temporary assignment to another, the IRS can classify you as an “itinerant” worker. An itinerant’s tax home is wherever they are currently working. The devastating consequence? You are never considered to be “traveling away from home,” and therefore, none of your travel expenses are deductible. I’ve seen colleagues lose over $100,000 in legitimate deductions over a few years because they fell into this trap without realizing it.

How to Establish and Maintain a Tax Home:

• Have a Primary Work Area: Maintain a consistent base of operations. This could be a part-time W-2 job, a regular PRN gig at a local hospital, or even a consistent relationship with a surgery center in your home city where you pick up shifts between longer locum assignments.
• Keep Assignments Temporary: A key factor is that your locum assignments must be temporary, meaning they are realistically expected to last for one year or less. If an assignment extends beyond a year, your tax home may shift to that location.
• Return Home: You must actually return to your tax home area between assignments. Spending all your time on the road without a business reason to be in your home city weakens your case.

The rules are detailed in IRS Publication 463, “Travel, Gift, and Car Expenses.” Misunderstanding this single concept is the most expensive mistake a full-time locum physician can make. Don’t let it be you.

Geographic Arbitrage: Your Domicile is a Financial Tool

As an anesthesiologist, your clinical skills are highly portable. This portability creates a massive opportunity for tax planning that most W-2 employees don’t have: geographic arbitrage. By establishing legal domicile in a state with no income tax, you can potentially save tens of thousands of dollars per year, even if you work primarily in a high-tax state.

The nine states with no state income tax are Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. Imagine living in tax-free Austin, Texas, and flying to California for a week of locum shifts. You will still owe California state income tax on the income earned in California, but all your other income—from investments, a spouse’s work, or locum work in other tax-free states—is not taxed at the state level.

The How-To Sequence for a Legitimate Domicile Change:

Simply getting a P.O. box in Florida isn’t enough. State tax authorities are aggressive about auditing former high-income residents. To prove you have truly changed your domicile, you need to sever ties with your old state and establish new ones. This means:

1. Establishing a Primary Residence: Buy or lease a home or apartment in the new state. This must be your true primary home.
2. Changing Legal Documents: Get a new driver’s license, register your vehicles, and register to vote in the new state. Update your passport and all financial accounts with your new address.
3. Moving Your “Center of Life”: Move your family, enroll children in local schools, join local community groups or religious organizations, and find local doctors and dentists. The more you can show your life is centered in the new state, the stronger your case.
4. Tracking Your Days: Be mindful of the “183-day rule” that many high-tax states use. Spending more than 183 days in a state like New York or California can make you a statutory resident for tax purposes, regardless of your domicile.

This strategy requires commitment, but for a high-earning physician, the annual savings can be equivalent to an extra month’s salary.

FIRE Strategies for a High-Burnout Specialty

Anesthesiology is a rewarding but demanding field. The long hours, high-stakes environment, and shift-work nature contribute to a high rate of burnout, leading many of us to consider financial independence and retiring early (FIRE). The challenge isn’t just saving enough money; it’s structuring your accounts to access those funds before the traditional retirement age of 59.5 without incurring a 10% penalty.

Most physicians focus on maxing out their 401(k)s and IRAs, which is a great start. But if you plan to retire at 50, that money is locked up for nearly a decade. The key is building a “bridge account” to cover your living expenses from your early retirement date until age 59.5.

The Key Tools for an Early Retirement Bridge:

• Aggressive Taxable Brokerage Investing: This is your primary bridge account. After maxing out all tax-advantaged retirement accounts (Solo 401(k), Backdoor Roth IRA, HSA), direct a significant portion of your savings into a standard, taxable brokerage account. Invest in tax-efficient index funds. When you retire, you can sell these assets and pay long-term capital gains tax, which is often much lower than ordinary income tax rates.
• Roth Conversion Ladder: This is a more advanced strategy. You roll over pre-tax funds from a Solo 401(k) or traditional IRA into a Roth IRA. You pay income tax on the converted amount in the year of the conversion. After five years, you can withdraw the converted principal tax-free and penalty-free. By doing a conversion each year, you create a “ladder” of funds that become accessible five years down the road.
• Rule 72(t) – SEPP: The Substantially Equal Periodic Payments (SEPP) rule allows you to take penalty-free distributions from your IRA or 401(k) before age 59.5. The catch is you must take a calculated annual withdrawal for at least five years or until you turn 59.5, whichever is longer. The calculation methods are rigid, and a mistake can trigger retroactive penalties on all previous withdrawals. This is a powerful but inflexible tool, best used with professional guidance.

The most important part of a FIRE strategy is withdrawal sequencing. In early retirement, you’ll likely draw from your taxable brokerage first, then tap your Roth conversion ladder, and finally draw from your traditional pre-tax accounts after 59.5. Getting this sequence right minimizes your lifetime tax bill. The physician finance hub is a useful AI-powered tool designed to help model these complex scenarios and identify which strategies best fit your personal timeline and financial picture.

Supercharging Deductions with Cost Segregation Studies

For anesthesiologists who invest in real estate—whether it’s a medical office building or a portfolio of residential rentals—a cost segregation study is one of the most powerful tax strategies available. When you buy an investment property, the building is typically depreciated over 27.5 years (for residential) or 39 years (for commercial). This provides a slow, steady stream of tax deductions.

A cost segregation study is an engineering-based analysis that dissects the property into its various components and reclassifies them into shorter depreciation schedules. Instead of treating the entire building as one asset, it identifies components that can be depreciated over 5, 7, or 15 years. Examples include:

• 5-Year Property: Carpeting, cabinetry, specialty electrical wiring, decorative lighting.
• 7-Year Property: Furniture and fixtures.
• 15-Year Property: Land improvements like landscaping, sidewalks, and parking lots.

By reclassifying, say, 25% of a $1 million building’s cost basis from a 39-year schedule to a 5-year schedule, you can pull decades’ worth of tax deductions into the first few years of ownership. This creates a massive “paper loss” that can offset other income.

The Trap to Avoid (and the Pro-Tip): For most physicians, real estate losses are considered “passive” under IRS §469 and can only offset passive gains. They cannot offset your active 1099 or W-2 income. However, if your spouse qualifies for Real Estate Professional Status (REPS), this changes everything. To qualify, your spouse must spend more than 750 hours per year and more than 50% of their total working time on real estate activities. If they meet this test and you file jointly, your rental losses become non-passive. The massive depreciation loss from a cost segregation study can then be used to directly offset your high clinical income, potentially wiping out a huge portion of your tax liability.

You can model the potential returns and depreciation impact of a property using a real estate investing calculator to see if this strategy makes sense for your portfolio.

Navigating the transition from a W-2 employee to a 1099 business owner is complex, but the financial rewards for getting it right are immense. These strategies—from the S-corp election to sophisticated real estate tax planning—are the building blocks of a robust financial plan that can accelerate your wealth-building and provide career flexibility. The key is to move from being a passive W-2 earner to an active manager of your own financial enterprise. If you’re ready to optimize your business structure and tax strategy, talk to us about your locum structure and we can help you map out the next steps.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 21, 2026