Headdresses, as opulent markers of rank and affiliation, offer a unique opportunity to examine sociopolitical roles and offices at Teotihuacan. In particular, in light of the few surviving glyphic texts from the site, the representations of headdresses, either in isolation, as part ritual investitures, or actively worn by individuals, are in fact one of the few ways to achieve a deeper understanding of the nature, structure, and institutional aspects of social stations and in the ancient metropolis. In this paper, we will first discuss the elemental properties of headdresses in Teotihuacan iconography as well as the rites of accession upon which these symbolic markers were acquired. Thereafter, we suggest that several kinds of headdresses are also associated with specific named houses at Teotihuacan, which indicate their close affiliation with certain powerful institutions. Finally, we focus on some of the specific types of headdresses, and especially those qualified by the so-called Year Sign (Figure 1). Based on comparisons with Classic and Epiclassic calendrical records, wherein dates are also crowned by the same headdress, as well as with the diadem of the Late Postclassic Mexica rulers, the xiuhhuitzolli, we put forth a new interpretation of its meaning at Teotihuacan.