The salience of principles & practices of subsidiarity in IHRL is linked to value pluralism & communal self-determination. I argue that an analysis of the variations in the practice of subsidiarity by different IHRL mechanisms is a useful proxy to elucidate the idea of legitimate interpretive pluralism in IHRL, defined as a plurality of incompatible, albeit correct, interpretations of the requirements of human rights that are simultaneously valid under the same mechanism. The scope of interpretive pluralism depends on reasons associated with the grounds & nature of human rights, and on second-order reasons, eg the credibility of domestic institutions. Interpretive pluralism also suggests that IHRL mechanisms are open to adjustments in their aims & modes of activity for reasons of communal self-determination. This is important for effective human rights protection because respect for value pluralism can nurture individual loyalty to IHRL institutions and cement their role & functions.