Settlements of federal civil actions may, but need not, be subject to later judicial enforcement. As recognized by the U.S. Supreme Court in Kokkonen v. Guardian Life Insurance Co., one significant limitation on enforcement proceedings is subject matter jurisdiciton because federal district courts are courts of limited jurisdiction. Under Kokkonen, enforcement jurisdiction may be independent, but usually is ancillary because state law claims typically are involved where there is no diversity of citizenship. Ancillary enforcement powers may be exercised by district courts either where claims were initially presented for adjudication and disputes arising from later settlements are factually interdependent, or where recognition of enforcement authority enables courts to function successfully, as when courts need to insure that their orders are not flouted or imperiled. Typically, enforcement authority is exercised so that the courts function successfully. Difficulties have surfaced regarding this ancillary settlement enforcement jurisdiction. They include how to incorporate settlement terms into court orders and how otherwise to retain jurisdiction, whether settlement disputes may prompt the reopening of judgments, and what contract laws and what procedures should apply when federal case settlements are enforced. There are additional troubles which have yet to surface significantly, including whether there is judicial discretion to refuse requests that future enforcement jurisdiction be retained and whether certain settlement disputes can prompt discretionary refusals of available enforcement jurisdiction. We believe new written federal laws are needed now to address many of these difficulties. Relevant lawmakers include both the U.S. Supreme Court, as promulgator of the Federal Rules of Civil Procedure, and the Congress. We suggest amendments to the Federal Rules of Civil Procedure on judgment entry, on judgments involving money and on permanent injunctions, as well as to the supplemental jurisdiction statute.