Usually, drains remain in place for about two weeks after a tummy tuck, however sometimes they do remain longer.
Every plastic surgeon manages drains a little differently. In most cases, suctions drains are left in until the total output is less than 30cc (one ounce) for a 24 hour period. There are some plastic surgeons who prefer to not use drains, and instead utilize progressive tension sutures and/or tissue glues. It is best to clear up this issue with your plastic surgeon ahead of time to avoid any confusion.