What it is
Federal income tax withheld from your taxable pay, based on the W-4 you filed in myPay or with your finance office. Basic pay and most special pays are taxable. BAH and BAS are not.
2026 rate
Depends on your W-4 elections and taxable wages.
What goes wrong
Withholding is not a fixed percentage, so do not panic over month-to-month changes after a raise or bonus. Do check the marital status and exemptions fields on the LES match what you filed. In a designated combat zone your taxable wages drop to near zero for enlisted members, and that shows here.