Nitrogen oxides (NO_x = NO + NO₂) in the troposphere form an array of secondary pollutants that are detrimental to air quality, ecosystems, and climate. The family of reactive oxidized nitrogen (NO_y) in the atmosphere consists of NO_x and its reservoir species (e.g. HNO₃, PAN). Our understanding of the processes underlying the transformation of NO_y has advanced considerably over recent decades, however, the relative importance of NO_y partitioning and loss pathways remain uncertain. In this study, we use the GEOS-Chem global chemical transport model and observations from the ATom flight campaign to assess the simulated global budget of tropospheric NO_y, and the production and loss fluxes between key NO_y species. Our simulation indicates that the mean global chemical lifetime of NO_x is ~21 hours and the mean global deposition lifetime of NO_y is 5.5 days. The global mean NO_x:NO_y ratio at the surface is 0.23 (over continents it is 0.34) and at 500 hPa is 0.10. In addition to the four most prevalent gas-phase species (NO, NO₂, HNO₃, PAN) that have been central to previous descriptions of tropospheric NO_y chemistry, we find that other species play key roles in driving overall chemical cycling.<strong> </strong>The model representation of organic nitrate chemistry is highly simplified and likely overestimates the importance of hydrolysis as a sink while underestimating deposition. Finally, the photolytic loss of particulate nitrate (pNO₃^-) to form NO₂ and HONO, as represented in our simulations, is comparable to its depositional loss, indicating the importance of further constraining this photolysis sink.