Yes, to a certain extent. Hair has 3 stages of growth; anagen, catagen and telogen. Anagen is the active stage of growth, which is the ideal time to have treatment. The hair root is attached to the papilla (blood supply responsible for hair growth) and is in its prime stage to be treated.
Keeping your regularly scheduled appointments as recommended by your Electrologist will allow the hair to be treated in this ideal stage of growth. If there is too much time in between appointments, the hair can move into the catagen stage.
Catagen is when the root detaches itself from the papilla, and the hair begins to move up the follicle wall. The lower portion of the follicle collapses, which makes it difficult to reach the papilla. The papilla is the target the Electrologist must destroy in order to achieve permanency. The hair then moves into the telogen phase, where the hair sheds. Once the hair falls out on its own, the follicle may become dormant for a couple of weeks up to about 4 months, or it may begin producing another hair right away. When a follicle is in the telogen or resting phase, it cannot be treated as there is no visible hair.
You simply have to wait for it to go back to the anagen stage and have the hair removed at that point. Those who want to wait for all the hair in a given area to grow back before having a subsequent appointment are doing themselves a disservice. The best way to have Electrolysis take the least amount of time to achieve permanency is to remove the hair as soon as it becomes visible.