Global model predictions have large uncertainties in the prediction of ultrafine aerosol concentrations, particularly in pristine regions in both the lower and upper troposphere. Not adequately representing the formation of new particles and their growth rates to larger sizes can impact predictions of cloud condensation nuclei (CCN) and consequently aerosol indirect effects. In this study, we describe the inclusion of 11 new particle formation (NPF) mechanisms that are coupled to a nucleation mode added to the four-mode version of the Modal Aerosol Model (MAM4) in E3SM. These NFP mechanisms are a synthesis of molecular-level experiments that describe the complex chemical transformation of precursor gases. Global E3SM simulations with the new representation of ultrafine particles show that predicted total particle number concentrations and aerosol size distributions are improved when compared with ARM and other measurements. The dominant NPF mechanism varies with region and altitude, demonstrating the complexity of NPF formation processes and the importance of accounting for many precursor gases (including extremely low volatile organic compounds, ELVOCs) when simulating the aerosol lifecycle worldwide. We find that NPF accounts for a range of fractions (10-80%) of CCN at 0.5% supersaturation, depending on the region. The representation of many NPF mechanisms will also facilitate our understanding of source apportionment of aerosols, including how specific emission changes between the pre-industrial and present day conditions affect the growth of particles to CCN sizes.