What it is
Members in essential station messing (typically junior enlisted in the barracks) receive BAS but pay back most of it through a daily meal deduction for dining facility meals. The two lines travel together: BAS in, meal deduction out.
2026 rate
A daily rate set annually, deducted for each day of the month.
What goes wrong
This deduction should stop the month you are authorized to move out of essential station messing, get BAS in full, and buy your own groceries. It continuing after you moved out is one of the most common junior enlisted pay errors.