A reticulocyte count test is a diagnostic blood test that measures the number of immature red blood cells, called reticulocytes, in a person’s bloodstream. Reticulocytes are produced by the bone marrow and eventually mature into fully-formed red blood cells. A reticulocyte count can be used to diagnose and monitor various medical conditions, such as anemia, bone marrow failure, and other blood disorders. The test is typically performed as part of a complete blood count (CBC) and involves analyzing a blood sample under a microscope. The results of a reticulocyte count can provide valuable information about a person’s bone marrow function and the effectiveness of treatments being used to manage their condition.