The health plan must read and write HIPAA standard transactions exactly as they are described in the standard implementation guides. The only exception would be if the guide explicitly gives discretion regarding a data element to a health plan. For claims and most other transactions, the receiver must accept and process any transaction that meets the national standard. This is necessary because multiple health plans may be scheduled to receive a given transaction (e.g., a single claim may be processed by multiple health plans).
For example: Medicare currently instructs providers to bill for certain services only under certain circumstances. Once HIPAA standard transactions are implemented, Medicare will have to forego that policy and process all claims that meet HIPAA specifications. This does not mean that Medicare, or any other health plan, has to change payment policy. Today, Medicare would refuse to accept and process a bill for a face lift for cosmetic purposes only. Once the HIPAA standards are implemented, Medicare will be required to accept and process the bill, but still will not pay for a face lift that is purely for cosmetic purposes.