Depends on what kind of chamomile you are growing :-) Unfortunately, the common name 'chamomile' applies to two different plants but ones that share similar attributes and uses. Matricaria chamomila is an annual. Anthemis nobilis (aka Chamaemelum nobiie) is a perennial.

I'm not sure if the seed packets I have bought had the genus and species on them. I'm going to have to get a more reliably labeled source. I have really liked them in the garden spot where I put them this year but they died right after blooming so I think they must be the annual kind. I started them in a pot last year and they managed to overwinter so I thought they were perennial.

I am in Zone 7a/b and I never see my Roman chamomile survive. I suspect the animals are eating it (we have deer, rabbits, etc.).