There's no age minimum in this state but minors require a parents permission. This is written in the state law.

I've been to a few dispensaries in both WA and CA, and they always left me wondering what the big deal was. By that I mean that I got better quality at a better price from "drug dealers"

The thing that always makes me laugh about this subject is that I'm pretty sure most people with authorizations smoked herb BEFORE they got their card, this always makes me wonder why they don't just stick with what they know until they (or their provider) can grow some for them. 4 months from seed to bong isn't really that long.