Unwind by Neal Shusterman
In a future world where those between the ages of thirteen and eighteen can have their lives "unwound" and their body parts harvested for use by others, three teens go to extreme lengths to uphold their beliefs--and, perhaps, save their own lives.
Review from School Library Journal:
An unsettling futuristic novel set after the Second Civil War. Connor Lassiter, age 16, runs away from his suburban Ohio home after discovering that his parents have scheduled his "unwinding." His body parts will go to other people who need them. He will be both terminated and "technically" kept alive, only in a separated state. The constitutional amendments known as "The Bill of Life" permit parents to choose "retroactive" abortion for children between the ages of 13 and 18. Connor meets another Unwind, Risa, and they kidnap Lev, who is a Tithe (the 10th child born to a single family with the express purpose of being unwound). Their escape and survival stories interweave as they struggle to avoid harvest camps. Luckily, an underground network is helping Unwinds escape to safety. There is evenhanded, thoughtful treatment of many issues, including when life starts and stops, consciousness, religion, free will, law, trust and betrayal, suicide bombers, and hope. Initially, the premise of parents dismantling their children is hard to accept; however, readers are quickly drawn into the story, which is told in a gripping, omniscient voice. Characters live and breathe; they are fully realized and complex, sometimes making wrenchingly difficult decisions. This is a thought-provoking, well-paced read that will appeal widely, especially to readers who enjoy Scott Westerfeld's Uglies (2005), Pretties (2005), and Specials (2006, all S & S).