48 CFR §2101.370

1. (a)Except as provided in paragraphs (b) and (c) of this section, an amendment to the LIFAR is effective when promulgated or as provided in the amendment.
2. (b)Except as provided in paragraphs (c) and (d) of this section, if the LIFAR is amended in a manner which would increase the contractor's(s') costs or liabilities under the contract(s), the amendment will be made effective the October 1 subsequent to the amendment's promulgation, unless the contractor(s) agree(s) in writing to an earlier date.
3. (c)Except as provided for in paragraph (d) of this section, if the LIFAR is amended between July 31 and October 1 in a manner which would increase the contractor's(s') costs or liabilities under the contract(s), the amendment will not be effective until the October 1 in the year following the amendment's promulgation, unless the contractor(s) agree(s) in writing to an earlier date.
4. (d)Paragraphs (b) and (c) of this section are not applicable to amendments that are necessary to implement new or existing legislation.
5. (e)OPM will not initiate any changes to the LIFAR during a continuity of services period, as discussed in section 2152.237-70 of this chapter.