Varies. With all the information we now have about hpv--we know if you test negative for hpv, you can safely go 2-3 yrs before another pap needed. Most dysplasia (abnormal cells)-if mild or moderate, will revert back to normal--but you need to make sure of this. Severe pre-cancerous changes are treated aggressively. I have seen cancer in women who have been lax on pap for 5 years-normal 5 years ago!