The submittal of claims to insurance companies requesting payment for medical services provided by a doctor to a patient is called the medical billing process: preregistration of patients; establishment of financial responsibility for the visit; checking in the patients; checking out the patients; the review of coding compliance; verifying billing compliance; the preparation and transmittal of claims; the monitoring of payer adjudication; generation of patient statements; and the follow-up of payments by the patient and the handling of collections. HCPCS, HIPAA, CPT and ICD have an influence on every step of the process. The 9th revision – Clinical Modification (ICD-9) is a global categorization of diseases and contains sets of codes. These codes give information for evenly measures and diagnoses. The ICD-9 code has three digits, and these three may be followed by a decimal point and then two more digits. The Healthcare Common Procedure Coding System (HCPCS) does not give diagnosis information, only information about the procedure area. The purpose of HCPCS code is to process hospital treatments for outpatient services. Physicians also use these codes. ICD-9 procedure codes are required by HIPAA for the reporting procedures of hospital inpatients. The numerical codes for CPT and diagnoses are assigned by the coding team. They make these assignments based on information given by the provider. A charge is then created, following the billing rules that pertain to certain locations and carriers. People who work on the process of medical billing have to maintain patient information confidentially based on HIPAA rules. Employees must also be truthful and conduct themselves with integrity. Every procedure and diagnosis has to be correctly documented and then coded accurately to avoid any delays in payment.