The eligibility for a health plan transaction is the transmission of either of the following:
(a) An inquiry from a health care provider to a health plan, or from one health plan to another health plan, to obtain any of the following information about a benefit plan for an enrollee:
(1) Eligibility to receive health care under the health plan.
(2) Coverage of health care under the health plan.
(3) Benefits associated with the benefit plan.
(b) A response from a health plan to a health care provider's (or another health plan's) inquiry described in paragraph (a) of this section.