Section 1179 of HIPAA, Processing Payment Transactions by Financial Institutions, states that to the extent that an entity is engaged in activities of a financial institution (as defined in section 1101 of the Right to Financial Privacy Act of 1978), or is engaged in authorizing, processing, clearing, settling, billing, transferring, reconciling, or collecting payments, for a financial institution, this part, and any standard adopted under this part, shall not apply to the entity with respect to such activities, including the following . . . (SEE ATTACHMENT, codification in 42 USC 1320d-8 for some specific examples of activities exempted). The part referenced in the sentence above is Part C of HIPAA, Administrative Simplification, and the regulations/standards regarding protection of privacy of personal health information are adopted under Part C. Therefore, the bank is exempt from HIPAA, Part C, Administrative Simplification, to the extent the bank is engaged in activities of a financial institution.
Also, a guidance paper from the Office of Civil Rights, dated 12/03/02, gives an example of the exemption for financial institutions relating to the business associate contract on page 41-42, see the last bullet on page 42 (if you print the guidance paper, it may be numbered within each section, in which case you need to go to the "Business Associates" section and see page 4-5, last bullet on page 5).
As to how this information is personal health information:
Customers will sometime include health billing information in with their payments. Also, the fact that a check is written to Dr. Snips Vasectomy Clinic is personal health information.