Q3 Estimated Taxes Are Due September 15: What CRNAs and Business Owners Need to Know

If you're a 1099 contractor or you run your business through an S-corp with owner draws, September 15 is one of four dates a year the IRS expects a check, whether or not you've been tracking it. Missing it doesn't just delay a payment. It can trigger an underpayment penalty even if you pay everything you owe in full by April.

Who actually needs to pay this

If taxes aren't being withheld from your income the way they would be from a W-2 paycheck, you're generally on the hook for estimated payments. That covers most CRNAs working as 1099 contractors, business owners taking S-corp distributions on top of a reasonable salary, and anyone with significant income the IRS doesn't already see withholding on, think locum work, investment income, or a side practice.

The safe harbor rule

The IRS gives you a built-in way to avoid the penalty even if your estimate isn't exact. Generally, you're safe if you pay in, through withholding and estimates combined, at least 90% of what you owe for the current year, or 100% of what you owed last year (110% if last year's adjusted gross income was over $150,000). Hit either threshold and the penalty doesn't apply, even if your final bill is bigger than what you paid in.

How to actually estimate the payment

Start with last year's total tax liability if this year looks similar, that's often the simplest safe harbor to hit. If your income has changed meaningfully (a new contract, a shift in business structure, a strong year), work from a current-year projection instead: total expected income, minus deductions, run through your expected bracket, minus what's already been withheld or paid this year. Divide what's left by the number of remaining payment periods.

The bottom line

If you're not sure where you stand, now is the time to check, not October. A quick review before the 15th can be the difference between a manageable payment and an unexpected penalty on top of it.

Contact Abell & Advisors if you want to talk through what this looks like for your specific situation.