Although the medical device and pharmaceutical industries are related, they are governed by distinct regulatory systems. Despite the similarities, the inherent differences between medical devices and drugs have implications for clinical research and medical writing. There has been a recent move to adopt more stringent regulatory requirements for the medical device industry, bringing the environment closer to what we have come to expect from the highly regulated pharmaceutical industry. The present article is a follow-up to a previous article published in Medical Writing in 2017, which introduced writing for medical devices and the challenges for medical writers coming from a pharmaceutical regulatory environment. In this article, we present our current knowledge about authoring documents for medical devices, the parallels with the pharmaceutical regulatory system, and the essential guidance documents.