In Maine, the possession limits for marijuana vary depending on whether you're using it recreationally or medically:
Recreational Use (Adults 21+)
Up to 2.5 ounces of marijuana or marijuana products.
Within that, no more than 5 grams can be marijuana concentrate.
Medical Marijuana Patients
Limits are generally aligned with recreational use unless otherwise specified by a physician.
Patients may also possess up to 6 mature plants, 12 immature plants, and unlimited seedlings for personal medical use.