Probably, but not always. It depends on how far the pitch has dropped below A-440 (Standard Pitch). If the pitch is very near A-440, one regular tuning may be all that is required.
In some cases, especially if the pitch is substantially below A-440, a Pitch Raise tuning may be required (performed at the same time as the regular tuning, at additional cost).
In other cases, a regular tuning followed by another tuning in a few weeks will suffice. In either case the objective is to re-stabilize the piano so that it will hold its tuning again. Often it takes a couple of years to re-stabilize a piano that has not been tuned for many years, with tunings being scheduled further apart as the piano stabilizes.
Your Piano Technician will be able to give you the options before beginning the tuning process.