Best Entity Structure for Physicians: LLC vs S-Corp vs C-Corp
Your business entity is the foundation of every tax strategy. Choose wrong and you overpay taxes, miss deductions, and limit growth. Here is how to choose right.
A guide by Taxstra Tax & Accounting — CPA-led tax strategy for business owners
18 min read · Updated March 2026 · By Bryan Martin, CPA
Entity Types Explained
Sole Proprietorship, LLC, S-Corp, and C-Corp for Physicians
Every physician with self-employment income operates through a business entity — whether they realize it or not. If you have not formally organized, you are a sole proprietor by default. That means unlimited personal liability for business debts and malpractice claims, and the highest possible self-employment tax rate on every dollar of net income.
Choosing the right entity structure is the single most impactful tax decision a physician business owner can make. It determines how you are taxed, how you are protected from liability, what retirement plans you can access, and how your practice is valued if you sell. Here is what each entity type means for physicians.
Sole Prop
Default. No formation. Maximum SE tax. No liability protection.
LLC
Liability protection. Flexible tax treatment. Low cost to form.
S-Corp
Tax election on LLC/Corp. Payroll tax savings. Pass-through income.
C-Corp
Separate tax entity. 21% corporate rate. Double taxation risk.
Sole Proprietorship
A sole proprietorship is not a formal entity — it is the default classification when you earn self-employment income without forming an LLC or corporation. You report income on Schedule C of your personal return. All net income is subject to 15.3% self-employment tax (Social Security 12.4% + Medicare 2.9%) on the first $168,600, plus 2.9% Medicare on everything above that, plus the 0.9% Additional Medicare Tax above $200,000 (single) or $250,000 (MFJ).
For a physician netting $300,000 as a sole proprietor, self-employment tax alone is approximately $27,000+. There is no liability protection — your personal assets (house, savings, investments) are exposed to malpractice claims and business debts. This is the most expensive and riskiest structure for a physician.
LLC (Limited Liability Company)
An LLC provides liability protection — separating your personal assets from business liabilities. By default, a single-member LLC is a disregarded entity for tax purposes (taxed like a sole proprietorship on Schedule C). A multi-member LLC is taxed as a partnership.
The power of the LLC is its tax flexibility. You can elect to be taxed as an S-Corp (Form 2553) or even a C-Corp (Form 8832) without changing the legal entity. This means you form one LLC and change the tax treatment as your income grows. For most physicians, the LLC is the foundation — you just change how it is taxed over time.
S-Corporation (S-Corp Tax Election)
The S-Corp is a tax election, not a legal entity type. You file Form 2553 to elect S-Corp treatment on your LLC or corporation. The key benefit: you split income into a reasonable W-2 salary (subject to payroll taxes) and distributions (not subject to self-employment tax). For a physician netting $350,000 with a $175,000 salary, the distributions of $175,000 avoid approximately $10,000+ in Medicare and self-employment taxes.
S-Corp income is pass-through — it flows to your personal return. There is no corporate-level tax. This makes S-Corps the most popular entity choice for physicians with net income above $60,000-$80,000. Read our full S-Corp election guide for detailed analysis.
C-Corporation (C-Corp)
A C-Corp is a separate tax entity that pays its own federal income tax at a flat 21% rate. When profits are distributed as dividends to shareholders, they are taxed again at qualified dividend rates (0%, 15%, or 20%). This double taxation makes C-Corps more expensive for most physician practices that distribute all profits.
However, C-Corps have advantages in specific situations: deducting 100% of health insurance premiums as a business expense (not subject to the self-employed health insurance deduction limitations), funding generous defined benefit pension plans, retaining earnings at the lower 21% corporate rate for reinvestment, and qualifying for Section 1202 QSBS exclusion (up to $10 million in capital gains excluded on sale). For physicians planning to build and sell a practice, the C-Corp can be strategically valuable.
Decision Tree by Income Level
When to Upgrade Your Entity Structure
Is your net self-employment income below $60,000/year?
Yes
Stay as a sole proprietorship or single-member LLC (disregarded). S-Corp costs ($1,500-$3,000/year for payroll + extra tax return) may exceed savings at this income level.
No
Continue to next question.
Is your net self-employment income between $60,000 and $150,000/year?
Yes
Elect S-Corp tax treatment. At $100,000 net income with a $60,000 salary, you save approximately $6,120 in self-employment tax annually. The savings clearly exceed S-Corp administration costs.
No
Continue to next question.
Is your net self-employment income between $150,000 and $400,000/year?
Yes
S-Corp is almost certainly optimal. At $300,000 net income with a $175,000 salary, payroll tax savings are approximately $10,000-$15,000/year. Consider QBI deduction optimization as well.
No
Continue to next question.
Is your net self-employment income above $400,000/year?
Yes
S-Corp remains the standard choice for payroll tax savings. Evaluate whether a C-Corp makes sense for retained earnings, fringe benefits, or QSBS planning. Consider a multi-entity structure for non-clinical income.
No
You answered 'No' to all — revisit your income calculation or consult a tax professional.
Side-by-Side Comparison
Pros, Cons, and Best-For by Entity Type
| Factor | Sole Prop | LLC (Disregarded) | S-Corp | C-Corp |
|---|---|---|---|---|
| Formation Cost | $0 | $50-$500 | $50-$500 + Form 2553 | $50-$500 + Form 8832 |
| Liability Protection | None | Yes | Yes | Yes |
| Self-Employment Tax | Full (15.3%) | Full (15.3%) | Only on salary | N/A (corp pays) |
| Income Tax | Personal rates | Personal rates | Pass-through (personal rates) | 21% corporate + dividend tax |
| Payroll Required | No | No | Yes (owner salary) | Yes |
| Annual Filing | Schedule C | Schedule C | Form 1120-S + K-1 | Form 1120 |
| QBI Deduction | Yes (if eligible) | Yes (if eligible) | Yes (on distributions) | No (C-Corp income excluded) |
| Retirement Plans | SEP IRA, Solo 401(k) | SEP IRA, Solo 401(k) | Solo 401(k), defined benefit | 401(k), defined benefit, cash balance |
| Health Insurance | Self-employed deduction | Self-employed deduction | Deductible (with S-Corp rules) | 100% corporate deduction |
| Owner Count | 1 | Unlimited | Max 100 shareholders | Unlimited |
| Annual Admin Cost | ~$200 | ~$200-$500 | ~$1,500-$3,000 | ~$2,000-$5,000 |
| Best For | Side gig < $60K | New practice, simplicity | Most physicians $60K+ | Retained earnings, QSBS, benefits |
S-Corp Is Not Always the Answer
The internet is flooded with advice telling every physician to elect S-Corp status. But S-Corps add real costs: payroll processing ($500-$1,500/year), an additional tax return ($800-$2,000/year), and quarterly payroll tax filings. If your net income is below $60,000, these costs can exceed the payroll tax savings. Always model the net benefit before electing.
Worked Example: Dermatologist, $450,000 Net Income, MFJ
Scenario: Dr. Santos, Dermatologist, Private Practice, MFJ
Net practice income: $450,000. Comparing entity structures.
| Tax Component | Sole Prop | S-Corp (Salary $200K) | C-Corp |
|---|---|---|---|
| Federal Income Tax | ~$120,000 | ~$120,000 | $94,500 (corp) + dividend tax |
| Self-Employment Tax | ~$27,500 | ~$10,800 (salary only) | $0 (FICA on salary only) |
| State LLC/Corp Fee (CA) | $6,000 LLC fee | $800 franchise tax | $800 franchise tax |
| Admin/Payroll Costs | $200 | $2,500 | $4,000 |
| QBI Deduction (est.) | Phased out (SSTB) | Phased out (SSTB) | Not available |
| Total Tax Burden (approx) | ~$153,700 | ~$134,100 | Varies (double tax risk) |
| Annual Savings vs Sole Prop | Baseline | ~$19,600 | Depends on distribution strategy |
The S-Corp saves Dr. Santos approximately $19,600/year compared to sole proprietorship — primarily through payroll tax reduction on $250,000 in distributions. The C-Corp becomes attractive only if she plans to retain significant earnings in the corporation or is building toward a practice sale with QSBS eligibility.
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State-Specific Considerations
Where You Practice Changes the Math
Entity structure is not just a federal decision. State laws, fees, and taxes can significantly change which entity type is optimal. Here are the key state-level factors physicians must consider.
| State | Key Consideration | Impact on Entity Choice |
|---|---|---|
| California | $800 franchise tax + LLC fee ($900-$11,790 based on gross revenue) | High-revenue practices may prefer S-Corp formed as a PC to avoid LLC gross receipts fee. The $800 minimum applies regardless. |
| Texas | No state income tax. $0.00375/dollar franchise tax (margin tax) | S-Corp is highly favorable — no state income tax on pass-through income. Franchise tax applies to entities with revenue over $2.47M. |
| New York | NYC Unincorporated Business Tax (4%) on sole props and LLCs | NYC physicians should strongly consider S-Corp to avoid the 4% UBT on all net self-employment income. S-Corp distributions are exempt from UBT. |
| Florida | No state income tax. $150 annual LLC fee. | Very favorable for S-Corps. No state-level tax on pass-through income. Low formation and maintenance costs. |
| Illinois | 1.5% replacement income tax on S-Corp income (pass-through entity tax) | S-Corp still beneficial, but the 1.5% PTE tax reduces the net savings slightly. Can be used as a SALT cap workaround. |
| Washington | No income tax but B&O tax on gross receipts (1.5% for services) | B&O tax applies regardless of entity type. Does not change the S-Corp vs LLC analysis, but adds to overall tax burden. |
| New Jersey | Corporate Business Tax on C-Corps (6.5%-11.5%). PTE elective tax available. | S-Corp with PTE election can provide SALT cap workaround. C-Corp tax rates are high, making S-Corp more attractive. |
California's Hidden LLC Tax
California's LLC fee is based on gross revenue, not net income. A physician practice grossing $600,000 pays an $800 franchise tax plus a $2,500 LLC fee — totaling $3,300/year just for the privilege of being an LLC. A professional corporation (PC) with S-Corp election avoids the gross receipts fee entirely, paying only the $800 franchise tax. For California physicians, forming a PC instead of an LLC can save $900 to $11,000+ per year depending on revenue.
Multi-Entity Structures
Separating Clinical and Non-Clinical Income
Many physicians have income from multiple sources: clinical practice, consulting, real estate, coaching, expert witness work, or product sales. Running everything through a single entity is simple but expensive. A multi-entity structure can reduce taxes, protect assets, and preserve deductions — particularly the QBI deduction.
Common Multi-Entity Structures for Physicians
Clinical S-Corp + Non-Clinical LLC
The most common structure. Clinical practice income flows through an S-Corp for payroll tax savings. Non-clinical income (coaching, consulting, product sales) flows through a separate LLC that may qualify as a non-SSTB for QBI purposes. This structure preserves the 23% QBI deduction on non-medical income even when the physician is above the SSTB threshold.
Clinical S-Corp + Real Estate LLC(s)
Physician real estate investors hold rental properties in separate LLCs — one per property or per group of properties. This isolates malpractice liability from real estate assets and keeps rental income separate for QBI qualification (real estate can qualify for QBI through the safe harbor or as a trade/business).
Management Company Structure
A physician-owned management company provides administrative, billing, or staffing services to the medical practice. The management company pays a fair market value fee, shifting income from the SSTB medical practice to a potentially non-SSTB entity. This is an advanced strategy that requires genuine economic substance and arm's-length pricing.
How to Restructure Your Entity
Step-by-Step Conversion Paths
Restructuring your entity is more common than you think. Physicians evolve — incomes grow, side businesses emerge, states change. Here are the most common conversion paths and what they involve.
| Conversion | How | Key Deadline | Tax Implications |
|---|---|---|---|
| Sole Prop to LLC | File Articles of Organization with state. Get new EIN. | Anytime | Tax-neutral (disregarded entity by default) |
| LLC to S-Corp | File Form 2553 with IRS | March 15 (calendar year) or within 75 days of formation | Tax-neutral if timely filed. Late elections possible with reasonable cause. |
| LLC to C-Corp | File Form 8832 with IRS | 75 days before or 12 months after desired effective date | May trigger gain recognition on appreciated assets. Consult CPA. |
| S-Corp to C-Corp | Revoke S election (shareholder consent) | Must be filed by March 15 for current-year effect | No immediate tax, but future distributions face double taxation. |
| C-Corp to S-Corp | File Form 2553 | March 15 of the desired effective year | Built-in gains tax on appreciated assets for 5 years. |
| Sole Prop to S-Corp | Form LLC + File Form 2553 (two steps) | March 15 for current year | Tax-neutral if done correctly. Must start running payroll immediately. |
Do Not Miss the March 15 Deadline
The most common restructuring mistake is missing the March 15 deadline for S-Corp election. If you file Form 2553 after March 15, the election does not take effect until the following year — costing you a full year of payroll tax savings. Late election relief is available if you can demonstrate reasonable cause, but it is not guaranteed. Set a calendar reminder for January each year to evaluate your entity status.
Common Entity Mistakes Physicians Make
Avoid These Costly Errors
Mistake #1: Staying as a sole proprietor too long
Every year you earn $100,000+ as a sole proprietor without S-Corp election, you are overpaying approximately $6,000-$15,000 in self-employment taxes. The longer you wait, the more you lose.
Mistake #2: Forming an LLC but never electing S-Corp
An LLC without an S-Corp election is taxed identically to a sole proprietorship — you get liability protection but zero payroll tax savings. The LLC formation is only step one.
Mistake #3: Choosing a C-Corp without a specific reason
Some physicians (or their attorneys) form a C-Corp by default. Without a specific strategy for retained earnings, QSBS, or fringe benefits, the double taxation makes a C-Corp more expensive than an S-Corp for practices that distribute all profits.
Mistake #4: Running all income through one entity
Physicians with consulting, real estate, or product income lose QBI deductions and liability protection by co-mingling everything in a single medical practice entity.
Mistake #5: Ignoring state-level entity costs
A California LLC grossing $1 million pays $6,800/year in state fees. An S-Corp formed as a professional corporation pays $800. Ignoring state costs can mean thousands in unnecessary fees.
Mistake #6: Not updating the entity as income grows
Your entity should evolve with your career. The structure that made sense as a resident moonlighting on 1099 income is not the right structure when you are an attending earning $400,000+.
Need Help Choosing the Right Entity Structure?
We'll model the tax impact of each entity type for your specific income, state, and goals — and show you exactly how much you can save.
Find Out What You're Overpaying in Taxes
Book a free 30-minute call to walk through your situation. We'll tell you exactly how our CPA-led team can help — and whether we're the right fit.
What to Expect on the Call
Frequently Asked Questions
Entity Structure for Physicians
Related Physician Tax Guides
S-Corp Election for Physicians
Complete guide to S-Corp election, reasonable compensation, and payroll setup for physicians.
Read guideQBI Deduction for Physicians
Section 199A guide covering SSTB phase-outs, S-Corp salary tradeoff, and spin-off strategies.
Read guideEntity Structure Strategy Guide
The comprehensive entity structure guide for all professionals and business owners.
Read guidePhysician Retirement Plans
Solo 401(k), SEP IRA, cash balance plans, and defined benefit strategies for physicians.
Read guideYour Entity Structure Is the Foundation of Every Tax Strategy.
We'll analyze your income, state, practice type, and growth plans to recommend the optimal entity structure — and handle the formation, election, and restructuring for you. One call. Real numbers. No obligation.
Find Out What You're Overpaying in Taxes
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