Medical coding is the process of transforming healthcare diagnosis, procedures, medical services, and equipment into universal medical alphanumeric codes. Medical coders are health information professionals who analyze clinical statements and assign standardized codes using a classification system. They help ensure that the codes are applied correctly during the medical billing process, which includes abstracting the information from documentation, assigning the appropriate codes, and creating a claim to be paid by insurance carriers. Medical coding is required every time a patient visits a healthcare provider, and the codes translate the documentation into standardized codes that let payers know the patients diagnosis, the medical necessity for treatments, services, or supplies the patient was given, and any abnormal circumstances or medical condition that affected those treatments and services. Medical coders use a set of published codes on medical diagnoses and procedures, such as the International Classification of Diseases (ICD), the Healthcare Common Procedural Coding System (HCPCS), and Current Procedural Terminology (CPT) for reporting to the health insurance provider of the recipient of the care. Medical coding has three key phases: abstraction, assignment, and review. Medical coding specialists, also called medical coders, work off of transcriptions taken from medical records, doctors notes, lab test results, and other sources to translate details into universal medical codes to maintain accurate medical records.