With the recent approval of several drugs for the management of chronic hepatitis B, the proper diagnosis and classification of this disease is necessary to determine if therapy is needed and what the best treatment options are. The diagnosis of chronic hepatitis B relies on serological testing, and disease stage is further characterized with HBV DNA levels and an assessment of liver disease through biopsy or non-invasive methods. A regular screening protocol is necessary for patients with chronic hepatitis B to monitor the development of cirrhosis and hepatocellular carcinoma. Patients receiving treatment also need regular monitoring for response to determine if a different therapeutic regimen is needed or if drug-resistant variants are being selected. This review discusses the various tests for hepatitis B diagnosis and for monitoring disease progression and treatment response. In addition, noninvasive methods for classifying liver disease stage are discussed, as are special considerations that are needed for individuals coinfected with HIV.