S-Corp vs. LLC for Your Dental Practice: The Real Trade-Offs

Most dental practice owners chose their entity structure the week they signed their first lease, under pressure, trusting whoever was cheapest to set it up. That decision is now costing some of them real money, and saving others nothing at all.

The S-corp versus LLC question is genuinely nuanced. The right answer depends on your profit level, your state, your retirement goals, and how much administrative friction you are willing to tolerate. Here is how to think through each dimension honestly.

How Self-Employment Tax Actually Works in Each Structure

This is the centerpiece of the whole debate, so let's get it right.

A single-member LLC taxed as a sole proprietorship, or a multi-member LLC taxed as a partnership, subjects the owner's share of net profit to self-employment (SE) tax on the full amount. SE tax covers both the employee and employer sides of Social Security and Medicare. At profitable production levels, that is a meaningful number.

An S-corporation changes the math. The owner-dentist must take a reasonable W-2 salary, and that salary is subject to payroll taxes on both sides. But the remaining profit flows through as a distribution, and distributions are not subject to SE tax. The potential savings live in that gap between your total profit and your reasonable salary.

Three things to understand clearly:

• "Reasonable salary" is not a number you get to pick arbitrarily. The IRS expects it to reflect what you would pay a hired dentist doing your job. Underpaying yourself to maximize distributions is the IRS's single most common S-corp audit target.
• The Social Security wage base caps the employer and employee Social Security tax, so the SE tax savings from an S-corp concentrate heavily on the Medicare side once you exceed that cap.
• At lower profit levels, the savings can be modest. At higher profit levels, the savings can be substantial. The crossover point varies by state and by the specifics of your compensation structure. A qualified CPA should model this with your actual numbers.

Payroll Requirements and Administrative Cost

This is where the S-corp's reputation as a "pain in the neck" comes from, and it is partially deserved.

Once you elect S-corp status, you are running payroll. That means:

• Registering as an employer at the federal and state level
• Processing payroll on a regular schedule (not just when cash flow allows)
• Filing quarterly payroll tax returns (Form 941)
• Filing annual payroll forms (W-2, W-3, 940)
• Paying both the employee and employer halves of FICA on your salary

A single-member LLC taxed as a disregarded entity has none of this overhead. Profit hits your Schedule C or your partnership return, and you pay SE tax at filing time. Simpler, cheaper to administer.

Payroll service fees, additional bookkeeping time, and CPA fees for payroll compliance all add to the S-corp's annual cost. Those costs reduce the net benefit of the structure. At very high profit levels, the math still favors the S-corp by a wide margin. At more modest profit levels, the administrative overhead can consume much of the savings. This is a calculation, not a slogan.

Retirement Plan Interaction

This is where the S-corp story gets more complicated than most advisors explain at first.

With an S-corp, your retirement plan contributions are tied to your W-2 compensation, not your total profit. A solo 401(k) employer contribution, for example, is generally limited to a percentage of W-2 wages. If you set your salary conservatively to save on payroll taxes, you simultaneously limit how much you can shelter in a retirement plan.

With a Schedule C structure, your SE income drives the contribution limit calculation (after the SE tax deduction adjustment). In some cases, a very profitable sole proprietor or LLC member can actually shelter more in a retirement plan than an S-corp owner who set their salary too low.

The practical implication: salary and retirement plan strategy must be optimized together. A salary that looks right for SE tax purposes may be wrong for retirement plan purposes. Your CPA and financial advisor need to be in the same room, or at least the same conversation, when this gets designed.

State-Level Recognition and Dental Licensing Complexity

Federal tax law does not operate in a vacuum. Dental practice ownership is regulated at the state level, and those regulations interact directly with your entity choice.

Some states require that a dental practice operate as a professional corporation (PC) or professional limited liability company (PLLC), not a general LLC. In those states, a generic LLC may not be a legally valid structure for the practice itself.

Additionally:

• Some states impose their own franchise taxes or annual fees on S-corporations that can meaningfully reduce the federal tax benefit.
• California is a well-known example: the state imposes its own S-corp taxes and does not always recognize federal S-corp elections the same way the IRS does, creating a layered compliance picture.
• A handful of states do not recognize S-corp status at all for state income tax purposes.

This means the correct entity analysis for a dentist in Texas looks different from the correct analysis for a dentist in New York or California. National generalizations about "S-corps are always better" ignore this entirely.

Signals That It Is Time to Revisit Your Structure

Entity structure should not be a set-it-and-forget-it decision. The following are concrete signals that a review is overdue:

• Your practice profit has grown significantly since you formed the entity. The SE tax savings from an S-corp scale with profit. A structure that was not worth the overhead at lower production levels may now make strong sense.
• You acquired a second location or a partner joined. Multi-owner practices have more complex considerations around equity, distributions, and buy-sell planning that affect entity choice.
• You are within ten years of a planned sale. Entity structure has significant implications for how sale proceeds are taxed. An S-corp sale can often be structured as an asset sale with more favorable tax treatment than a C-corp, but the timing and method matter.
• Your state changed its rules. Professional licensing statutes and state tax treatment of pass-through entities have both been active areas of legislative change in recent years.
• You have never had a CPA model the actual numbers. If your entity was chosen based on a general recommendation rather than a projection of your specific profit, compensation, and retirement contributions, you are operating on assumptions, not analysis.
• You added a retirement plan or are considering a defined benefit plan. The interaction between compensation structure and plan contribution limits is complex enough to warrant a fresh look at the whole picture.

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FAQ

Can I convert my LLC to an S-corp without starting over? Generally, yes. An LLC can elect to be taxed as an S-corporation by filing Form 2553 without dissolving and reforming the legal entity. The timing of that election matters for when it takes effect, so plan ahead.

What is a "reasonable salary" really based on? The IRS looks at what a comparable dental professional would be paid for the same services in the same market. Factors include production, specialty, geographic area, and hours worked. There is a range, not a single right number, but it needs to be defensible.

Does an S-corp protect me from malpractice claims? Entity structure can provide some liability protection, but professional liability for clinical errors typically pierces entity protection regardless of structure. Malpractice insurance is your real protection there. Do not choose an entity for liability reasons without talking to both your attorney and your insurer.

Should the practice entity and the real estate entity be the same? Rarely. Real estate (if you own your building) is typically held in a separate LLC for liability isolation and tax flexibility. Mixing the two creates complications on a future sale.

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This article is general educational information only, not tax or legal advice for your specific situation. Consult a qualified CPA and attorney before making entity structure decisions.