Civil Defense Accountability Act of 2018 This bill directs the Department of Defense (DOD), in coordination with the Federal Communications Commission (FCC) and the Department of Homeland Security (DHS), to report to Congress regarding current notification protocols for ballistic missile threats. The Federal Emergency Management Agency (FEMA) must conduct, and report on, a study to identify best practices of at least 13 states, including Hawaii, Alaska, California, Washington, and other states bordering or not bordering on an ocean or the Gulf of Mexico, regarding civil defense emergencies. The bill requires key officials (defined to include the heads of DOD, FEMA, and the FCC) to submit to Congress and make publicly available unclassified reports on the actions of their respective departments or agencies regarding the ballistic missile false alarm that occurred on January 13, 2018, in Hawaii. Each report shall include recommendations for corrective actions to diminish the possibility of another ballistic missile false alarm. The Office of the Assistant Secretary for Preparedness and Response of the Department of Health and Human Services (HHS) must submit to Congress and publish online a report regarding the ability of HHS and health care providers to respond to attacks in the United States with biological, chemical, radiological, or nuclear weapons. HHS must (1) develop and implement a public outreach program in coordination with state and local governments regarding recommendations in such report for improving readiness in responding to such attacks, and (2) consider the report's recommendations when issuing grants under the Public Health Emergency Preparedness cooperative agreement and the Hospital Preparedness Program.