The purpose of this research was to generate a model of advanced medical nutrition therapy (MNT) practice based on descriptions of their clinical activities provided by advanced-level MNT practitioners. A qualitative approach using grounded theory methodology was employed. The model of advanced MNT practice was based on interviews with 21 credentialed advanced practice registered dietitians from across the United States and Canada. Verbatim transcripts of the interviews were coded for aggregation into themes and subthemes. The resulting model included a single overarching theme: using initiative to achieve autonomy. The five subthemes are aptitude, attitude, expertise, context, and approach. The model provides a richer picture of advanced MNT practice than was previously available and is presented for discussion and debate. Validation of the model is required before incorporation into education or practice.