The incorporation of small amounts of N into III-V antimonide-containing semiconductor alloys allows a drastic expansion of available wavelengths for infrared (IR) detector applications. Quaternary films containing three group-V elements can be lattice matched to the most prevalent substrates for IR applications, such as InAs, GaAs, and GaSb. It is not trivial to incorporate N while maintaining the high crystalline quality required for IR devices. Current materials characterization studies of dilute-nitride films consisting of more than two group-V elements has yielded conflicting information related to their competing behavior and the extent of N incorporation. Due to challenges related to light-element microanalysis for many characterization techniques, and the small concentrations of N involved, it is difficult to quantify the amount of N incorporated into dilute-nitride films. In this study, we use transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and x-ray diffraction (XRD) to study the incorporation behaviors of the competing group-V elements in InAsSbN films.