The New Aba Practice Tax Calendar: Every Deadline You Cannot Miss

2026-08-21

A practical 2026 tax calendar for new ABA practices: quarterly estimates, payroll, and annual deadlines with concrete steps.

Running an ABA practice means managing therapy sessions, staff, and insurance claims. Taxes can feel like a secondary headache, but missing a deadline triggers penalties that eat into your margins. This guide lays out every tax deadline you cannot miss in 2026, with realistic dates and steps you can take this week.

Why a Tax Calendar Matters for ABA Practices

ABA practices face unique tax obligations: payroll for RBTs and BCBAs, independent contractor vs. employee classification, and often multiple state filings if you provide telehealth across state lines. The IRS and state agencies do not extend deadlines for new businesses. Penalties for late filing run 5% of the unpaid tax per month, up to 25%. For a practice with $200,000 in annual revenue, that could mean $10,000 in avoidable penalties. A simple calendar prevents that.

Quarterly Estimated Tax Deadlines (Form 1040-ES)

If you operate as a sole proprietor, LLC, S-corp, or partnership, you pay estimated taxes quarterly. The IRS expects you to pay as you earn. For 2026, the deadlines are:

Q1: April 15, 2026 (for income earned Jan 1 to Mar 31)
Q2: June 15, 2026 (for income earned Apr 1 to May 31)
Q3: September 15, 2026 (for income earned Jun 1 to Aug 31)
Q4: January 15, 2027 (for income earned Sep 1 to Dec 31)

Each payment covers federal income tax and self-employment tax (15.3% for Social Security and Medicare). To avoid underpayment penalties, pay at least 100% of last year’s tax liability (110% if your adjusted gross income was over $150,000). For a new practice, use the annualized income installment method if your income is uneven, but that requires Form 2210. Most new owners simply pay 25% of their estimated annual tax each quarter.

Step this week: Calculate your projected 2026 net profit. Multiply by 15.3% for self-employment tax, plus your marginal income tax rate. Divide by 4. Set up automatic payments on the IRS Direct Pay system or EFTPS. Mark the four dates in your calendar with a recurring reminder.

Payroll Tax Deadlines (Form 941)

If you have W-2 employees (common for RBTs and administrative staff), you must withhold federal income tax, Social Security, and Medicare. You deposit these taxes on a semi-weekly or monthly schedule, depending on your total tax liability. The IRS assigns a schedule based on the lookback period. For most new practices, monthly deposits are due by the 15th of the following month. For example, January payroll taxes are due by February 15, 2026.

Quarterly, you file Form 941 by the last day of the month following the quarter:

Q1 (Jan-Mar): April 30, 2026
Q2 (Apr-Jun): July 31, 2026
Q3 (Jul-Sep): October 31, 2026
Q4 (Oct-Dec): January 31, 2027 (this is also the annual Form 940 due date)

Failure to deposit payroll taxes on time triggers a penalty of 2% to 10% of the amount, depending on how late. The IRS treats trust fund taxes seriously; personal liability can extend to owners.

Step this week: Confirm your deposit schedule with your payroll provider (Gusto, ADP, or Paychex). Ask them to send you a monthly calendar alert. Review your last Form 941 to ensure you filed on time.

Annual Business Tax Deadlines

Your practice’s structure determines which annual forms you file:

Sole proprietorship: Schedule C with your personal Form 1040, due April 15, 2026 (or October 15 with extension).
LLC (single-member): Same as sole proprietorship, but you may also need to file a state annual report.
Partnership (Form 1065): Due March 15, 2026. Extensions to September 15 are available, but you must file Form 7004.
S-corp (Form 1120-S): Due March 15, 2026. Extensions to September 15.
C-corp (Form 1120): Due April 15, 2026. Extensions to October 15.

For S-corps and partnerships, you must issue K-1s to owners by the original due date (March 15). Missing this deadline can delay your owners’ personal filings.

Step this week: If you have not already, choose your business structure. If you are an S-corp, confirm your payroll provider is running your owner’s salary. If you are a partnership, schedule a meeting with your accountant to prepare the K-1s.

State and Local Tax Deadlines

State income tax deadlines generally mirror federal, but not always. For example, California requires S-corp returns by March 15, but the state’s LLC fee is due April 15. Some states, like Texas, have a franchise tax due May 15. If you provide telehealth across state lines, you may have nexus in multiple states, triggering additional filings. Check with your state’s revenue department for a specific calendar.

Step this week: List all states where you have clients or employees. Visit each state’s tax website and note the due dates for income tax, sales tax (if you sell goods like therapy kits), and annual reports. Add them to your master calendar.

Estimated Tax Payment Vouchers and Electronic Filing

For 2026, the IRS requires electronic payment for any federal tax deposit over $2,500. Use EFTPS or the IRS Direct Pay system. For paper vouchers, you can use Form 1040-ES, but electronic is faster and provides confirmation. State systems vary; many accept credit cards with a convenience fee (typically 1.87% to 2.5%).

Step this week: Register for EFTPS if you have not. It takes 5 minutes. Set up alerts for each due date.

Common Mistakes New ABA Practices Make

Treating employees as independent contractors. RBTs who work set hours under your supervision are likely employees. Misclassification triggers back taxes, penalties, and interest. The IRS Form SS-8 can help you determine status.
Forgetting state unemployment insurance. You must register with your state’s workforce agency and pay unemployment tax quarterly. Rates vary from 0.5% to 6% of the first $7,000 to $40,000 in wages.
Ignoring the annual Form 1099-NEC. If you pay any contractor $600 or more (e.g., a billing service), you must issue Form 1099-NEC by January 31, 2027. Failure to file carries a penalty of $60 per form, up to $620,000 for large businesses.

FAQ

Q: What if I miss a quarterly estimated tax payment? A: The IRS charges a penalty based on the underpayment amount and the number of days late. The rate is roughly 7% per year, compounded daily. Pay as soon as possible to minimize interest. You can also adjust your next payment to cover the shortfall, but the penalty still applies.

Q: Do I need to pay estimated taxes in my first year of operation? A: Yes, if you expect to owe at least $1,000 in federal tax. If you started mid-year, use the annualized income method to avoid overpaying early. Many new practices underestimate and face a large bill in April; setting aside 25% to 30% of net income each month helps.

Q: Can I file for an extension on my business tax return? A: Yes, file Form 7004 by the original due date. This extends the filing deadline by 6 months, but it does not extend the payment deadline. You must pay any estimated tax due by the original date to avoid penalties.

Q: How do I handle taxes for telehealth services across multiple states? A: You may have nexus in each state where you have clients. This can trigger income tax, gross receipts tax, or sales tax obligations. Consult a CPA with multi-state experience. Many ABA practices use a professional employer organization (PEO) to manage payroll and tax compliance in multiple states.

The Bottom Line

A tax calendar is not optional for a new ABA practice. Missed deadlines cost money and stress. Start by marking the four quarterly estimated tax dates, the four Form 941 due dates, and your annual return due date. Set up electronic payments and reminders. If you are unsure about your structure or multi-state obligations, invest in a CPA who specializes in healthcare practices. The $200 to $500 per month you spend on professional advice is far less than the penalties you could face. Take one action this week: write down your next three deadlines on a physical calendar or set digital alerts. Your future self will thank you.