The New Fertility Clinic Tax Calendar: Every Deadline You Cannot Miss

2026-08-21

A practical tax deadline calendar for new fertility clinics in 2026, covering federal, state, and payroll obligations with actionable steps.

Opening a fertility clinic means juggling patient care with a stack of tax deadlines. Miss one, and you face penalties that eat into your margin. This guide lays out every key date for 2026, with realistic figures and steps you can take this week to stay ahead.

Q1 Deadlines (January to March)

January 31: File Form W-2 and 1099-NEC with the IRS and provide copies to employees and contractors. Penalties for late filing start at $60 per form, up to $630,000 for large businesses. For a small clinic, that’s still $60 to $250 per form, so don’t skip it.

February 15: If you have employees, verify their Form I-9 eligibility. This isn’t a tax deadline, but it ties into payroll compliance. Also, send Form 1095-B or C to employees if you offer health insurance.

March 15: File Form 1120-S for S-corporations, or Form 1065 for partnerships. If your clinic is an LLC taxed as an S-corp, this is your deadline. Extend to September 15 if needed, but you must pay any tax due by March 15 to avoid interest.

March 31: File Form 1120 for C-corporations. If you’re a C-corp, this is your deadline. Extend to September 15, but pay estimated tax by March 31.

Action this week: Pull your payroll records and confirm all W-2s and 1099s are filed. If you haven’t, e-file immediately to reduce penalties.

Q2 Deadlines (April to June)

April 15: Individual tax returns (Form 1040) are due for owners. Also, the first quarter estimated tax payment is due. For fertility clinics, estimated payments are typically 25% of your annual tax liability. If your clinic nets $150,000, expect to pay around $9,000 to $12,000 per quarter, depending on your structure.

April 30: File Form 941 for Q1 payroll taxes. This covers federal income tax withholding, Social Security, and Medicare. Late filing penalties are 5% of the unpaid tax per month, up to 25%.

June 15: Second quarter estimated tax payment due. Also, if you have foreign bank accounts over $10,000, file FinCEN Form 114 by this date.

Action this week: Set up a separate bank account for tax payments. Transfer 25% of each month’s revenue into it. This prevents cash flow surprises.

Q3 Deadlines (July to September)

July 31: File Form 941 for Q2. Also, file Form 5500 for retirement plans, like a 401(k), if you have one.

September 15: Third quarter estimated tax payment due. Also, file extended S-corp or partnership returns (from March 15).

September 30: If you’re a C-corp, file extended Form 1120 by this date.

Action this week: Review your quarterly revenue and adjust your estimated payments. If you’re ahead of projections, increase payments to avoid underpayment penalties, which are based on the federal short-term rate plus 3%.

Q4 Deadlines (October to December)

October 15: File extended individual tax returns (Form 1040).

October 31: File Form 941 for Q3.

December 15: Fourth quarter estimated tax payment due. This is your last chance to cover your tax liability for the year.

December 31: Deadline to set up retirement plans for the current year. Contributions reduce your taxable income, so consider a SEP IRA or solo 401(k) if you haven’t.

Action this week: Schedule a year-end tax planning meeting with your accountant. Review your equipment purchases, lab leases, and staffing costs to maximize deductions.

State and Local Deadlines

State tax deadlines vary. For example, California requires S-corp returns by March 15, while New York has a similar schedule. Check your state’s franchise tax board website. Also, many cities impose a gross receipts tax, like New York City’s, which is due quarterly. Budget $500 to $2,000 per year for state and local filings, depending on your location.

Payroll Tax Deadlines: A Monthly Breakdown

Payroll taxes are due either monthly or semi-weekly, depending on your deposit schedule. The IRS determines this based on your total tax liability. For most new clinics, monthly deposits are due by the 15th of the following month. For example, January payroll taxes are due February 15. Use IRS Form 941 to reconcile quarterly.

Common Penalties and How to Avoid Them

Late filing: 5% of unpaid tax per month, up to 25%.
Late payment: 0.5% of unpaid tax per month, up to 25%.
Underpayment of estimated tax: Interest at the federal short-term rate plus 3%.
Avoidance tip: Set up automatic payments through the Electronic Federal Tax Payment System (EFTPS). It’s free and reduces human error.

FAQ

Q: What if I miss a deadline? A: File as soon as possible. Penalties accrue monthly, but the IRS often waives them if you have a reasonable cause, like a medical emergency. Call the IRS or use Form 843 to request abatement.

Q: Do I need to file quarterly estimated taxes if I’m an LLC? A: Yes, if you’re a sole proprietor, partner, or S-corp shareholder. If you expect to owe more than $1,000 in tax, you must pay quarterly.

Q: Can I deduct IVF equipment purchases? A: Yes, under Section 179, you can deduct up to $1,250,000 in 2026 for equipment like ultrasound machines or lab incubators, as long as it’s placed in service by December 31.

Q: What’s the best way to track deadlines? A: Use a tax calendar app like TaxCaddy or QuickBooks. Or, create a spreadsheet with all dates and set reminders 10 days before each.

The bottom line

Your fertility clinic’s tax calendar is non-negotiable. Missing a deadline costs you money and stress. Start by marking these dates in your calendar, set up a separate tax account, and schedule a quarterly review with your accountant. Do that, and you’ll keep more of your revenue where it belongs: in your practice.