The Doctor of Nursing Practice (DNP) is a professional degree in nursing. In the United States, the DNP is one of three doctorate degrees in nursing, the others being the research degrees PhD and the Doctor of Nursing Science. Internationally, since the 1990s, there have been a wide number of doctorate degrees available for nurses, including DProf, PhD and others. Internationally all such doctoral nursing degrees include mandatory research elements and take longer than a single year to complete.