Infectious diseases represent significant risk to insurers worldwide. While the second half of the twentieth century brought dramatic reductions in deaths from communicable infectious diseases, those advances are being challenged by new threats including the proliferation of antimicrobial resistance and ongoing pandemic risk. However, new technologies are rapidly emerging which allow scientists and public health officials to monitor, manage, and counter infectious disease risks. This chapter addresses the multiple risks posed by infectious diseases and provides insights for insurers and underwriters to mitigate those risks.