After you put in your zip code, you’ll see a list of clinics. This includes some Giant locations, Adventist, and more! Some of these locations are currently vaccinating ALL 1B folks. Giant is vaccinating 1A, 1B, and 1C
One word of warning, it’s recommended to choose a site in your home county. I’ve heard of MoCo residents getting turned away from an appointment that they made in another county via the Maryland state clinics.