; and (2) may consult with— (A) any public or private association of medical providers; (B) any government agency; or (C) any other relevant expert, as determined by the Secretary. (d) Application (1) In general Subject to paragraph (2), a licensed health care professional may not provide health care services at any Service unit, unless the licensed health care professional successfully completes the credentialing procedures of the credentialing system developed and implemented under subsection (a). (2) Exemption Paragraph (1) shall not apply to licensed health professionals who were credentialed using existing Service policy prior to the date of enactment of the Restoring Accountability in the Indian Health Service Act of 2023 until the date on which those licensed health professionals are required to be re-credentialed in accordance with the credentialing system developed and implemented under subsection (a). (e) Nonduplication of efforts (1) In general To the extent that prior to the deadline described in subsection (a)(1), the Service has begun implementing or has completed implementation of a medical credentialing system that otherwise meets the requirements of this section, the Service shall not be required to establish a new credentialing system under this section. (2) Authority The Service may expand or enhance an existing credentialing system to meet the requirements of this section. (3) Review (A) In general Not less frequently than once every 5 years, the Service shall— (i) undertake a formal review of the credentialing system in effect on the date of the review