((a)) ** .—** The Secretary may modify the process under which the working group established under subsection (b) of conducts assessments under such section, the Secretary conducts formal evaluations under , and issues regulations under if—

((1)) such evaluations cover the evidence, data, and factors required by subsection (b) of such section 1173; and

((2)) a period of 180 days has elapsed following the date on which the Secretary submits the notice under subsection (b) regarding the modification.

((b)) ** .—** If the Secretary proposes to modify the process under which the working group established under subsection (b) of conducts assessments under such section, the process under which the Secretary conducts formal evaluations under , or issues regulations under , the Secretary shall submit to the Committee on Veterans’ Affairs of the Senate and the Committee on Veterans’ Affairs of the House of Representatives a notice of the proposed modifications containing the following:

((1)) A description of the proposed modifications.

((2)) A description of any exceptions to the requirements of such sections that are proposed because of limited available scientific evidence, and a description of how such evaluations will be conducted.