In the years since this novel was published, its central concern — the shortage of available transplant organs — has become a growing issue in the media and American legislatures. In Coma, the premise is that demand for organs will so outdistance supply that a black market will develop.

In Coma's scenario, the black market for human organs mimics the more mundane black market for automobile parts: instead of removing needed parts from a brain-dead person — equivalent to a totaled car — the black marketeers render a normal, essentially healthy person permanently comatose in order to fill orders for highly marketable organs. The sabotaged bodies are stripped of hearts, lungs, livers, and kidneys — in the same way parked cars are stripped of radios, batteries, and bumpers — and sold piecemeal to the highest bidders.