This is greatly influenced by the different billing and claim submission requirements that various insurance companies have in their claim adjudication processes and policies for reimbursement. They dictate what the medical practice needs to follow regarding guidelines for coding, documentation, and formats of bills so that all claims submitted will be processed correctly. Coverage changes, deductible changes, and copayment changes change the amount reimbursed and therefore need to be thoroughly checked and updated. Apart from this, the insurance companies may reject the claim due to errors or disparities and may ask for a resubmission or an appeal, hence complicating the procedure of medical billing services. Their policies regarding preauthorization and medical necessity affect claim approval and payment processing, hence proper communication and following of payer-specific rules is required to result in effective billing.