Organ donation to the extreme!

UNWIND by Neal Shusterman - In the not-too-distant future, a person's life is precious from conception until the age of 13, when parents who aren't happy with the way their child has evolved, can have them "unwound", where body parts are harvested and given to the highest bidder. You see this satisfies both the pro-lifers and the pro-choicers because technically no one ever dies. Their body parts continue to live on in other peoples' bodies. 16-year-old Connor decides to take matters into his own hands and run away from the "harvesting camp" before he can become one of the "unwinds". Along the way he discovers an underground world of unwinds where there is a whole new set of rules he must abide by or risk the same fate.

If you like that one here is another look at the topic...

THE ADORATION OF JENNA FOX by Mary E. Pearson - What would you do to save the life of someone you love? How many organ transplants can one person receive and still be the same person? What percentage of a person's body should remain in order to still be considered human? Does everyone hear voices of dead people? What really happened the night her two best friends died? Why can't she remember that night? These are all questions Jenna Fox asks herself after she wakes up from an 18-month-long "nap".

Found: The Missing, Book 1 by Margaret Peterson Haddix

What happens when a plane suddenly appears out of nowhere carrying nothing but 36 babies? There was no sign of the plane on the airport's radar, there was no flight crew on the plane. The plane was seen by only a handful of people and those people have mysteriously disappeared. Flash foward 13 years to a couple of boys playing basketball in the driveway. One of them receives a creepy letter that leads to a bizarre turn of events and perhaps a little bit of time travel.