Agency chartered under state laws that underwrites, administers, and sells many types of insurance plans (e.g., fire and marine, life, casualty, health, liability). For those it insures, it agrees to pay all legitimate claims that may arise under the policy in exchange for a monthly or annual premium. Also called agency or insurance agency, indirect payer, insurer , or payer . See also insurance carrier, fiscal agent , fiscal intermediary (FI) , or agency .