In this paper, the noun incorporation (NI) construction in Chuj and K'ichee' Mayan is examined. Formal explanations are proposed using the non-projecting semantic argument (NPSA) within the Lexical Functional Grammar (LFG) architecture. Derivational morphology indicates that NI is an analytical construct, and by inference, is post-lexically formed. Traditional NI semantic analyses, although productive, fall short of a full accounting. Consequently I show that the incorporated noun (Incorporate) represents a hybrid category of grammatical function (GF) that displays a mix of properties acquired from prototypical subcategorized GFs and non-subcategorized Adjuncts.