This study investigates the extent to which speakers of American Norwegian (AmNo), a heritage language spoken in the United States and Canada, use the indefinite article in classifying predicate constructions ('He is (a) doctor'). Despite intense contact with English, which uses the indefinite article, most AmNo speakers have retained bare nouns, i.e., the pattern of Norwegian as spoken in Norway. However, a minority of the speakers use the indefinite article to some extent. I argue that generally, this use of the indefinite article has arisen through attrition (i.e., a change during the lifetime of individuals), not through divergent attainment causing systematic, parametric change in the Norwegian grammar of these speakers. I also argue that representational economy is one of the factors that may have contributed to the relative stability of bare nouns.