An employee and an employer each pay half of the payroll taxes that fund Social Security and Medicare. When you are independent, you pay both halves. This is called self-employment tax. It is separate from income tax.
The rate is 12.4% for Social Security plus 2.9% for Medicare, which is 15.3% in total, and it generally applies to 92.35% of your net earnings from self-employment once those earnings reach $400 (IRS Topic 554). The Social Security part stops at an annual limit, which is $184,500 for 2026 (Social Security Administration). The Medicare part has no limit, and an Additional Medicare Tax of 0.9% applies to self-employment income above $200,000 for most filers, $250,000 for married couples filing jointly and $125,000 for married people filing separately (IRS Topic 560). You can deduct one-half of your self-employment tax when you figure your adjusted gross income (IRS Topic 554).
Quarterly estimated payments
Estimated payments are installments you send during the year, because no employer is withholding for you. In most cases you must make them if you expect to owe at least $1,000 in tax for the year after withholding and refundable credits, and you expect those credits to be less than the smaller of 90% of this year’s tax or 100% of last year’s (Form 1040-ES instructions). For tax year 2026 the four due dates are April 15, June 15 and September 15, 2026, and January 15, 2027, and the IRS publishes the dates for each year on Form 1040-ES. Paying too little or too late can bring an underpayment penalty (IRS Topic 306). Many states also have their own estimated tax rules, so check your state tax agency.
A simple habit: move a fixed share of every settlement into a separate savings account the day it arrives. A CPA can tell you what share fits your case.