7 Mistakes Solo Dentist Practices Make in Their First Year

Starting a solo dental practice is exciting, but the first year brings a steep learning curve, especially around taxes. Many new practice owners make avoidable errors that cost them thousands and create headaches with the IRS. This guide outlines the 7 most common tax mistakes solo dentists make in year one, with concrete steps to fix or prevent each one. By addressing these now, you can keep more of your hard-earned revenue and build a solid financial foundation.

1. Choosing the Wrong Business Structure

Many solo dentists start as a sole proprietorship because it’s easy, but this offers no liability protection and can lead to higher self-employment taxes. An S-corp or PLLC is often a better choice, but only if you plan properly.

• Sole proprietorship: No filing fees, but you pay 15.3% self-employment tax on all net income. Also, you’re personally liable for any lawsuits.
• S-corp: You pay yourself a reasonable salary (subject to payroll taxes) and take the rest as distributions, which are not subject to self-employment tax. This can save you $3,000 to $8,000 per year, depending on income. However, you must file Form 2553 and run payroll, which costs $50 to $150 per month for a service.
• PLLC: Offers liability protection and flexibility, but you still pay self-employment tax unless you elect S-corp status.

Action step this week: Consult with a CPA who specializes in dental practices. They can run the numbers for your expected income and recommend the best structure. If you’re already operating as a sole prop, you can still elect S-corp status within 75 days of your fiscal year start, or by March 15 for calendar-year filers.

2. Mixing Personal and Business Expenses

Using one bank account for both personal and practice expenses is a recipe for tax trouble. It makes bookkeeping a nightmare, increases the risk of missing deductions, and can trigger an audit.

• Open a separate business checking account and credit card immediately. Use them exclusively for practice expenses.
• Track every transaction with accounting software like QuickBooks or Xero. These cost $30 to $100 per month, but they save hours of time and reduce errors.
• Keep all receipts, even for small purchases. Use a receipt scanner app like Expensify or Shoeboxed.

Action step this week: Open a business bank account and credit card. Transfer all recurring practice bills to these accounts. Set up a simple spreadsheet or accounting software to categorize expenses from day one.

3. Underpaying Quarterly Estimated Taxes

As a self-employed dentist, you must pay estimated taxes quarterly (Form 1040-ES). Many new owners underestimate their income or forget to pay, leading to penalties and interest. The IRS expects you to pay at least 90% of your current year’s tax liability or 100% of last year’s (110% if your adjusted gross income exceeds $150,000).

• Calculate your estimated payments based on your projected net income. A general rule: set aside 30% to 40% of your net profit for federal and state taxes.
• Pay electronically via the IRS Direct Pay system or EFTPS. Deadlines are typically April 15, June 15, September 15, and January 15.
• If you miss a payment, catch up as soon as possible to minimize penalties.

Action step this week: Review your year-to-date income and compare it to your original estimates. Adjust your next quarterly payment accordingly. If you haven’t made any payments yet, start now to avoid a large bill in April.

4. Overlooking Deductions Specific to Dental Practices

New dentists often miss deductions that are unique to their field. These can add up to significant savings.

• Equipment and technology: Section 179 allows you to deduct the full cost of qualifying equipment (like digital X-ray machines, chairs, and software) in the year you purchase it, up to $1,050,000 for 2026. Bonus depreciation can also apply.
• Continuing education: Deduct travel, lodging, and registration fees for courses that maintain or improve your skills.
• Professional fees: Dues for the ADA, state dental associations, and specialty boards are deductible.
• Lab fees and supplies: These are direct costs of providing services and are fully deductible.
• Home office: If you have a dedicated space for administrative work, you may qualify for the simplified home office deduction ($5 per square foot, up to 300 square feet).

Action step this week: List all equipment purchases and professional memberships from this year. Provide this list to your accountant to ensure they’re captured on your tax return.

5. Not Tracking Mileage for Business Travel

If you drive to dental conferences, visit suppliers, or run errands for the practice, you can deduct mileage. The 2026 standard mileage rate is 67 cents per mile. Over a year, this can add up to $1,000 or more.

• Keep a mileage log in a notebook or app like MileIQ or TripLog. Record the date, miles, and purpose of each trip.
• Only business-related trips count. Commuting from home to your practice is not deductible.
• If you use your personal car for business, you can either deduct actual expenses (gas, repairs, insurance) or use the standard mileage rate. The standard rate is simpler and often yields a larger deduction.

Action step this week: Download a mileage tracking app and start logging all business trips. Review your calendar for past trips and estimate miles if you don’t have records.

6. Ignoring Retirement Plan Tax Benefits

Solo dentists can save significantly on taxes by contributing to a retirement plan. Common options include:

• Solo 401(k): For 2026, you can contribute up to $23,500 as an employee (plus $7,500 catch-up if over 50), and up to 25% of net self-employment income as an employer. Total contributions can reach $70,000 or more.
• SEP IRA: Allows contributions of up to 25% of net income, with a maximum of $70,000 for 2026. It’s easy to set up, but contributions are made only by the employer.
• SIMPLE IRA: For practices with employees, but as a solo you can use it too. Lower contribution limits ($16,000 in 2026) but no administrative costs.

These contributions reduce your taxable income dollar-for-dollar, potentially saving you thousands in federal and state taxes.

Action step this week: Open a Solo 401(k) or SEP IRA with a provider like Fidelity, Vanguard, or Charles Schwab. Set up automatic transfers to fund it before year-end.

7. Waiting Until April to Think About Taxes

Procrastination is the biggest mistake. If you wait until tax season, you’ll miss opportunities to save and may scramble to gather records.

• Schedule quarterly check-ins with your accountant (January, April, June, September) to review your financials and adjust withholding or estimates.
• Keep your books updated monthly. Use a bookkeeper if needed; they cost $200 to $500 per month, but they save you time and reduce errors.
• Set aside a percentage of each payment you receive into a separate tax savings account. Aim for 25% to 30% of net income.

Action step this week: Book a meeting with your CPA for next month. Set up a recurring monthly task to reconcile your accounts and categorize expenses.

FAQ

Can I deduct the cost of my dental license and DEA registration?

Yes, these are ordinary and necessary business expenses. Keep receipts and include them in your professional fees deduction.

What if I miss a quarterly estimated tax payment?

You’ll owe a penalty based on the amount and time late. Pay as soon as possible to minimize it. The IRS may waive penalties if you can show reasonable cause.

Should I hire a CPA or use tax software?

For a first-year practice, a CPA who knows dental practices is worth the $500 to $1,500 cost. They can catch deductions and structure your business correctly, saving you more than their fee.

How long should I keep tax records?

Keep all tax returns and supporting documents for at least 7 years. This includes receipts, bank statements, and mileage logs.

Related guides

• Bookkeeping for Solo Dentist Practices: A Beginner’s Guide

The bottom line

Your first year as a solo dentist is a time to build good habits. Avoid these 7 mistakes to keep more of your income, stay compliant, and reduce stress. Start with the action steps this week: choose the right business structure, separate your finances, pay estimated taxes, track deductions, and plan for retirement. A little effort now pays off in peace of mind and real savings at tax time.