45 CFR §155.270

1. (a)HIPAA administrative simplification. To the extent that the Exchange performs electronic transactions with a covered entity, the Exchange must use standards, implementation specifications, operating rules, and code sets that are adopted by the Secretary in 45 CFR parts 160 and 162 or that are otherwise approved by HHS.
2. (b)HIT enrollment standards and protocols. The Exchange must incorporate interoperable and secure standards and protocols developed by the Secretary in accordance with section 3021 of the PHS Act. Such standards and protocols must be incorporated within Exchange information technology systems.