Part III Essays 41. Discuss how correctly linking diagnoses to procedures on the CMS-1500 form can corroborate the medical necessity for a procedure that has been performed. 42. Describe how to locate the local coverage determination (LCD) for the local Medicare administrative contractor (MAC). 43. Explain the reason for assigning CPT/HCPCS modifiers. 44. If an improper payment has been paid by a third-party payer, what are the steps that should be performed prior to the appeal? 45. Define the two types of ASCs and the main differences between the billing procedures. 289