Wearable medical devices are provided. An exemplary wearable medical device includes a printed circuit board assembly (PCBA) comprising a dielectric layer having a top surface and conductive features on the top surface of the dielectric layer. Further, the exemplary wearable medical device includes a top housing mounted directly to the top surface of the PCBA. Also, the wearable medical device includes a power source located between the top housing and the PCBA. The top housing and the dielectric layer of the PCBA encapsulates the conductive features and power source and define an outer surface of the wearable medical device.