Unwind:

The Bill of Life states that human life may not be touched from the moment of conception until a child reaches the age of thirteen. However, between the ages of thirteen and eighteen, a parent may choose to retroactively "abort" a child . . . on the condition that the child's life doesn't "technically" end. The process by which a child is both terminated and yet kept alive is called 'unwinding.' -Neil Shusterman, Unwind

Unwinding means that the child's organs are harvested. This satisfies the condition that the child is both terminated and kept alive, albeit in a distributed state among recipients of the child's organs. This law came to exist because there were insufficient voluntary organ donors.

Being unwound can happen for the most trivial of reasons. A religious family "tithes" it's tenth child to the harvest camps. The state orphanage has a budget crisis and decides to unwind five percent of its wards. One of the girls is chosen to be unwound by the state because she demonstrates insufficient promise as a musician.

The story is horrifying, but works because of the matter of fact way the author describes it. The story is about a child that makes a run for it, rather than being unwound.