FreeStyle Libre Flash Glucose Monitoring System Post Approval Study

Inclusion Criteria: * Subject must be at least 18 years of age. * Subject must have a diagnosis of type 1 or type 2 diabetes mellitus. * Subject is currently using SMBG for managing their diabetes. * Subject must be able to read and understand English * In the investigator's opinion, the subject must be able to follow the instructions provided to him/her by the study site and perform all study tasks as specified by the protocol. * Subject must have access to an internet connected computer for uploading data from the blood glucose meter and FreeStyle Libre system. * Subject must be willing and able to provide written signed and dated informed consent. Exclusion Criteria: * Subject is a member of the Site Staff. * Subject is currently using or has previously used a continuous glucose monitoring system for managing their diabetes * Subject has known allergy to medical grade adhesive or isopropyl alcohol used to disinfect skin. * Subject is pregnant or is attempting to become pregnant at the time of enrollment. * Subject is on dialysis at the time of enrollment. * Subject has concomitant medical condition which, in the opinion of the investigator, could interfere with the study or present a risk to the safety or welfare of the subject or study staff. * Subject currently is participating in another clinical trial. * Subject is unsuitable for participation due to any other cause as determined by the Investigator.