4 months post lipo my belly button is still numb. Is this permanent?

Permanent numbness after liposuction is possible but extremely rare and unlikely. Generally give this up to two years before drawing any final solutions.

There are many cases of sensory return after a year or more from its onset.  Frequently, though, the patient feels occasional tingling or "crawling" sensations as the nerve wakes up from its procedure-related sleepiness (neuropraxia).  Permanent sensation differences, both a lack of as well as hypersensitivity, are possible side effects of liposuction and are tolerated for the other benefits of the procedure. Should it occur, it is not something that would be avoidable, it is just the way the body heals.