What it is
State income tax withheld for your state of legal residence, which is not necessarily the state where you are stationed. Military members keep one state of legal residence as they move, and several states do not tax military pay at all.
2026 rate
Depends on your state of legal residence.
What goes wrong
If you legally changed your state of residence and the LES still shows the old state, you are having the wrong state's tax withheld, and unwinding that at tax time is painful. The state code on your LES is worth checking once a year.