Abstract: A new and useful in-line internal plumbing line sanitizers for appliances apparatus that sanitizes the internal plumbing lines of appliances such as refrigerators with integrated ice makers and drinking water dispensers, is easily adaptable, can be made in different sizes for use with various appliances, and can house a variety of sanitizing agents. The apparatus can also be used by an ordinary consumer, increases the safety and efficiency of internal plumbing line sanitation procedures, and eliminates the need for expensive replacement of internal appliance plumbing lines. This device is believed to be useful in the domestic and commercial settings. A device according to the invention is also believed to be favorable for use by appliance service technicians, as well as lay people who want to sanitize an appliance periodically.