Congress enacted the following amendments to the Endangered Species Act (ESA) in 1978:
- Provisions were added to section 7, allowing federal agencies to undertake an action that would jeopardize listed species if the action is exempted by a Cabinet-level committee convened for this purpose;
- Critical habitat was required to be designated concurrently with listing a species, when prudent, and economic and other impacts of designation were required to be considered in deciding on boundaries [section 4];
- The Secretary of Agriculture (for the Forest Service) was directed to join the Secretaries of Interior, Commerce, and Defense in developing a program for conserving fish, wildlife and plants, including listed species; land acquisition authority was extended to all such species [section 5];
- The definition of "species" with respect to "populations" was restricted to vertebrates; otherwise, any species, subspecies, or variety of plant, or species or subspecies of animal remained eligible for protection under the ESA [section 3].
Congress enacted the following amendments in 1982:
- Determinations of the status of species were required to be made solely on the basis of biological and trade information, without consideration of possible economic or other effects [section 4];
- A final rule to determine the status of a species was required to follow within one year of its proposal unless withdrawn for cause. This requirement replaced a two-year limit that had been enacted in 1978 on adopting a final rule. Failure to meet the two-year deadline had been grounds for mandatory withdrawals of more than 1,500 proposed species listings in 1979 [section 4];
- Section 10 included a provision to designate experimental populations of listed species that could be subject to different treatment under section 4 for critical habitat, section 7 for interagency cooperation, and section 9 for prohibitions;
- Section 9 included a prohibition against removing endangered plants from land under Federal jurisdiction and reducing them to possession;
- Section 10 introduced habitat conservation plans, providing "incidental take" permits for listed species in connection with otherwise lawful activities.
Congress enacted the following amendments in 1988:
- Monitoring candidate and recovered species was required, with adoption of emergency listing when there is evidence of significant risk [section 4];
- Several amendments dealt with recovery matters: 1) recovery plans were required to undergo public notice and comment, and affected Federal agencies were required to give consideration to those comments; 2) new subsection 4(g) required five years of monitoring recovered species; and 3) biennial reports were required on the development and implementation of recovery plans and on the status of all species with plans;
- A new section 18 required a report of all reasonably identifiable expenditures by the Federal government and States that received section 6 funds on a species-by-species basis on the recovery of endangered or threatened species; and
- Protection for endangered plants was extended to include a prohibition on malicious destruction on Federal land and other "take" that violates State law [section 9].
In 2004, in accordance with the National Defense Authorization Act (Public Law number 108-136), Congress enacted an associated amendment to the Endangered Species Act (ESA).
Section 4(a)(3) exempted the Department of Defense from critical habitat designations so long as an integrated natural resources management plan prepared under section 101 of the Sikes Act (16 U.S.C. 670a) and acceptable to the Secretary of the Interior is in place.