The purpose of this guideline is to maximise the safety of adults with interstitial lung disease, including idiopathic pulmonary fibrosis and pulmonary sarcoidosis, during the COVID-19 pandemic. It also aims to protect staff from infection and enable services to make the best use of NHS resources. This guideline focuses on what you need to stop or start doing during the pandemic. Use it alongside your usual professional guidelines, standards and laws (including equalities, safeguarding, communication and mental capacity), as described in making decisions using NICE guidelines. This guideline is for: health and care practitioners; health and care staff involved in planning and delivering services; commissioners. The recommendations bring together: existing national and international guidance and policies; advice from specialists working in the NHS from across the UK. These include people with expertise and experience of treating adults with interstitial lung disease during the current COVID-19 pandemic. We developed this guideline using the interim process and methods for developing rapid guidelines on COVID-19 in response to the rapidly evolving situation. We will review and update the recommendations as the knowledge base develops using the interim process and methods for guidelines developed in response to health and social care emergencies.