They're coming from Meyer Hatchery and I didn't opt to vaccinate, so I assume they won't be. I don't remember using it last time either, just a "nervous Nelly" waiting for my chicks to get here, lol.My hubby said "no more birds" after my cockatiel died, and then years later, he agreed to 3 baby chicks. Well the 3 chicks turned into 10 chickens, and now he's even given in on the cockatiel, though I have no plans to get another since they're far more time demanding than chickens.
You'll probably need the big bag. I get 10 lb of starter for 4 chicks and that lasts til about week 6 for me (though that's with adults eating some of it, and both adults and chicks also being offered an all flock feed).
Medicated is up to you, but make sure the chicks aren't vaccinated for coccidiosis as the medicated feed will nullify the vaccination.