For more information regarding Bristol-Myers Squibb Clinical Trial participation, please visit www.BMSStudyConnect.com  Inclusion Criteria:  Participants are included in Cohort 1 - Augment if they meet the following criteria:  Adults18 years or older Diagnosis of histologically confirmed R/M SCCHN, from any of the following primary sites only: oral cavity, oropharynx, hypopharynx, and larynx between 01-Jun-2017 and 31-June-2018. Prescribed 1L treatment for R/M SCCHN Treatment history and response available for medical chart abstraction from date of diagnosis until death or the end of the study in living participants Have available for review one month of follow-up data available post initiation of 1L R/M SCCHN therapy Informed consent form (ICF) signature/collection of living participants, as required by country regulation and local ethics committees  Participants are included in Cohort 1 if they meet the following criteria:  Adults 18 years or older Diagnosis of histologically confirmed R/M SCCHN, from any of the following primary sites only: oral cavity, oropharynx, hypopharynx and larynx between 01-Jan-2014 and 31-Dec-2016. Prescribed 1L treatment for R/M SCCHN Treatment history and response available for medical chart abstraction from the date of diagnosis until death or the end of the study in living participants Have available for review one month of follow-up data post initiation of 1L R/M SCCHN therapy Informed consent form (ICF) signature/collection of living participants, as required by country regulation and local ethics committees  Exclusion Criteria:  Participants were excluded from either cohort if they meet the following criteria:  Were enrolled in a cancer treatment-related clinical trial since the diagnosis of R/M SCCHN Recurrent or metastatic carcinoma of the nasopharynx, squamous cell carcinoma of unknown primary site, squamous cell carcinoma that originated from the skin and salivary gland or non-squamous histologies (e.g., mucosal melanoma).