From Global Naps, Inc. v. Verizon New England Inc., 2010 U.S. App. LEXIS 8929 (1st Cir. April 29, 2010):

In an issue of first impression for this court, we hold that 28 U.S.C. § 1367, enacted in 1990, gives federal courts supplemental jurisdiction over both compulsory and at least some permissive counterclaims. This alters this circuit's former rule, adopted before the enactment of § 1367, that required permissive counterclaims to have an independent basis for jurisdiction. See McCaffrey v. Rex Motor Transp., Inc., 672 F.2d 246, 248 (1st Cir. 1982). Our ruling brings us into line with the Second and Seventh Circuits.... Jones v. Ford Motor Credit Co., 358 F.3d 205, 210-14 (2d Cir. 2004); Channell v. Citicorp Nat'l Servs., Inc., 89 F.3d 379, 384-87 (7th Cir. 1996). ***

GNAPs argues no federal jurisdiction exists over Verizon's two successful counterclaims, count one to enforce the ICA [interconnection agreement] and count three alleging alter ego liability and disregard of the corporate form. ***

[W]e conclude Verizon's counterclaim is properly in federal court. We think it is clear that, at a minimum, there is supplemental jurisdiction under § 1367 over Verizon's counterclaim to enforce the ICA. We agree with Verizon that Congress did not withdraw that jurisdiction to hear this counterclaim in the TCA [Telecommunications Act of 1996]. See Verizon Md. Inc v. Pub. Serv. Comm'n, 535 U.S. 635, 644, 122 S. Ct. 1753, 152 L. Ed. 2d 871 (2002) (holding that § 252 of the TCA "at least does not divest the district courts of their authority under 28 U.S.C. § 1331"); see also United States v. Lahey Clinic Hosp., Inc., 399 F.3d 1, 9 (1st Cir. 2005) (noting that a "strong presumption against implied repeals of federal statutes is even stronger when the federal statute in question confers federal jurisdiction).

Verizon's counterclaim is more than sufficiently related to GNAPs' complaint. Both parties' claims ultimately arise from a dispute over the same agreement and involve the same basic factual question: what fees the carriers owe each other. ***

GNAPs makes a different and more complicated argument that there is no federal jurisdiction over count three, which alleged alter ego liability and disregard of the corporate form against GNAPs and the other defendants. GNAPs argues that at most this counterclaim is permissive, not compulsory. As such, GNAPs concludes, the counterclaim is outside federal courts' supplemental jurisdiction and requires an independent basis for jurisdiction. We hold that we have supplemental jurisdiction over this counterclaim, regardless of whether it is compulsory or permissive.

This court has not before considered the scope of statutory supplemental jurisdiction over counterclaims. The supplemental jurisdiction statute, 28 U.S.C. § 1367, was enacted in 1990. Some decisions before the enactment of § 1367 adopted a rule that federal courts could exercise supplemental jurisdiction over compulsory but not permissive counterclaims.***

This distinction arose from judge-made law of jurisdiction over what are now called supplemental claims — claims that lack an independent basis for federal jurisdiction — law which evolved in the absence of explicit congressional authorization. Put simply, courts distinguished jurisdiction over pendent claims — those brought by the plaintiff — and ancillary claims — those brought by third parties. Pendent claims had to arise from the same "common nucleus of operative fact" as the underlying claim having a basis for federal jurisdiction. United Mine Workers v. Gibbs, 383 U.S. 715, 725, 86 S. Ct. 1130, 16 L. Ed. 2d 218 (1966). Lower courts held that ancillary claims, such as counterclaims, had to arise from the same transaction or occurrence. ***

Not all courts agreed. Judge Friendly rejected the conventional view. See United States v. The Heyward-Robinson Co., Inc., 430 F.2d 1077, 1088 (2d Cir. 1970) (Friendly, J., concurring). So did Judge Becker. Abromovage v. United Mine Workers of Am., 726 F.2d 972, 988-90 (3d Cir. 1984). They and some commentators criticized this rule as historically and legally unsound and unwise. ***

In 1990 Congress enacted a supplemental jurisdiction statute, 18 U.S.C. § 1367. The statute does not use the terminology of "permissive" or "compulsory." It gives federal courts supplemental jurisdiction over all claims that are part of the same Article III case or controversy:

Except as provided in subsections (b) and (c) or as expressly provided otherwise by Federal statute, in any civil action of which the district courts have original jurisdiction, the district courts shall have supplemental jurisdiction over all other claims that are so related to claims in the action within such original jurisdiction that they form part of the same case or controversy under Article III of the United States Constitution.

28 U.S.C. § 1367(a). This language confers jurisdiction over all claims that are part of the same Article III case, subject to two exceptions, listed in subsections (b) and (c), which do not apply here.

[Footnote 20] Subsection (b) restricts supplemental jurisdiction in diversity cases over some kinds of claims, but not counterclaims brought under Rule 13. See 28 U.S.C. § 1367(b); Allapattah, 545 U.S. at 559-60. Specifically, it excepts, in diversity actions, "claims by plaintiffs against persons made parties under Rule 14, 19, 20, or 24 of the Federal Rules of Civil Procedure" and claims by people seeking to join under Rule 19 or intervene under Rule 24. 28 U.S.C. § 1367(b). These claims must meet all requirements for diversity jurisdiction. Id. This list does not include Rule 13, and in any event this case was not brought in diversity.

Subsection (c) allows district courts to decline to exercise supplemental jurisdiction when "the claim raises a novel or complex issue of State law," when the supplemental claim "substantially predominates over" the underlying claim properly in federal court, when "the district court has dismissed all claims over which it had original jurisdiction," or "in exceptional circumstances." The district court in this case did not opt to decline jurisdiction.

By its plain text, then, § 1367(a) governs supplemental jurisdiction over counterclaims. See Exxon Mobil Corp v. Allapattah Servs., Inc., 545 U.S. 546, 558-59, 125 S. Ct. 2611, 162 L. Ed. 2d 502 (2005) (interpreting § 1367(a)'s plain text, which confers a "broad grant of supplemental jurisdiction"). We join two circuits and virtually all commentators in holding that Article III's case-or-controversy standard is the jurisdictional limit for counterclaims. ***