This report documents radionuclide air emissions that result in the 2018 highest effective dose equivalent (EDE) to an offsite member of the public, referred to as the maximally exposed individual (MEI). The report has been prepared in compliance with the Code of Federal Regulations, Title 40, Protection of the Environment, Part 61, National Emission Standards for Hazardous Air Pollutants, Subpart H, “National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities” and Washington Administrative Code Chapter 246-247, “Radiation Protection–Air Emissions.” The dose to the PNNL Richland Campus MEI from routine major and minor point source emissions in 2018 from PNNL Richland Campus sources is 1.6E-5 mrem (1.6E-7 mSv) EDE. The dose from all fugitive sources is 2.1E-6 mrem (2.1E-8 mSv) EDE. The dose from radon emissions is 5.6E-10 mrem (5.6E-12 mSv) EDE. No nonroutine emissions occurred in 2018. The total radiological dose to the MEI from all PNNL Richland Campus radionuclide emissions, including fugitive emissions and radon, is 1.8E-5 mrem (1.8E-7 mSv) EDE, or more than 10,000 times less than the federal and state standard of 10 mrem/yr, with which the PNNL Richland Campus is in compliance.