The answer is yes, but in a complicated fashion. At the present moment, I am working on six books. Here is where I am in order of publication date:
Catch You Later, Traitor (March 10, 2015, Algonquin) I just reviewed the final comments and questions by a very sharp proofreader.
Old Wolf (August 8, 2015, Atheneum/S&S) My work appears to be finished on this novella, but I will be reviewing the illustrations being done by Brian Floca.
School of the Dead (fall 2016, HarperCollins) I am awaiting the first proof reading, after which I am sure there will be some work to be done.
Short Stories (2016, Candlewick) My editor and I agreed to take out two of the stories originally submitted, and had me write two more. Now I am making revisions on all seven stories. Need to agree on a title, and the sequence of stories.
A Medieval novella (No title. No set date. Atheneum/S&S) I Have only written about a third of this one and am still doing research.
Untitled historical fiction (No date, Algonquin) I am still in the research stage for this one.
Notice that each of these books is at a different place. All have different deadlines. It is that, more than anything, which makes this kind of work possible.