Yes. The undercoat is shed at least once per year, known as “blowing coat.” Grooming is extremely important at this time, as the dead coat must be brushed out or mats will form. It is possible to brush out a pile of hair which seems to be equal to the size of the dog being groomed, but this is not an ongoing condition. About ten minutes per day of brushing (a little more during the few weeks of shedding per year) will keep the coat glossy & healthy. Nails should be kept to a short length to protect the feet from splaying. This is particularly important in a giant breed, as the feet support a significant load.
Most Newfoundlands shed a LOT in the Spring, and then again in the Fall. The Fall shed is usually less severe then the Spring one.