; and (2) include such terms as the parties intend shall control during the term of the compact. (c) Amendment A compact under subsection (a) may be amended only by agreement of the parties. (d) Effective date The effective date of a compact under subsection (a) shall be— (1) the date of the execution of the compact by the parties; or (2) such date as is mutually agreed upon by the parties. (e) Duration A compact under subsection (a) shall remain in effect— (1) for so long as permitted by Federal law; or (2) until termination by written agreement, retrocession, or reassumption. (f) Existing compacts An Indian Tribe participating in self-governance under this title, as in effect on the date of enactment of the PROGRESS for Indian Tribes Act , shall have the option at any time after that date— (1) to retain its negotiated compact (in whole or in part) to the extent that the provisions of the compact are not directly contrary to any express provision of this title; or (2) to negotiate a new compact in a manner consistent with this title. 405. General provisions (a) Applicability An Indian Tribe and the Secretary shall include in any compact or funding agreement provisions that reflect the requirements of this title. (b) Conflicts of interest An Indian Tribe participating in self-governance shall ensure that internal measures are in place to address, pursuant to Tribal law and procedures, conflicts of interest in the administration of programs. (c) Audits (1) Single agency audit act Chapter 75 of title 31, United States Code, shall apply to a funding agreement under this title. (2) Cost principles An Indian Tribe shall apply cost principles under the applicable Office of Management and Budget circular, except as modified by— (A) any provision of law, including section 106