COLLATERAL ORDER DOCTRINE
The collateral order doctrine is a 'practical construction' of the final judgment rule of 28 U.S.C. section 1291. Digital Equipment Corp. v. Desktop Direct, Inc., 114 S.Ct. 1992, 1995 (1994). The doctrine allows appeals from 'a small class [of orders] which finally determine claims of right separable from, and collateral to, rights asserted in the action, too important to be denied review and too independent of the cause itself to require that appellate consideration be deferred until the whole case is adjudicated.' Cohen v. Beneficial Loan Corp., 337 U.S. 541, 546 (1949).
The doctrine applies only to: 'those district court decisions  that are conclusive,  that resolve important questions completely separate from the merits, and  that would render such important questions effectively unreviewable on appeal from final judgment in the underlying action.' Digital Equipment, 114 S.Ct. at 1995-96 (the 'Cohen requirements').
Immediate appeals may be taken from orders denying claims of immunity on one of the following grounds: the sovereign immunity granted to states under the Eleventh Amendment, Puerto Rico Aquaduct & Sewer Auth. v. Metcalf & Eddy, 113 S.Ct. 684, 688 (1993); the sovereign immunity of Guam, Marx v. Guam, 866 F.2d 294, 296 (9th Cir.'89); foreign sovereign immunity derived from the Foreign Sovereign Immunities Act, 28 U.S.C. sections 1602-1611, Compania Mexicana de Aviacion, S.A. v. United States Dist. Ct., 859 F.2d 1354, 356 (9th Cir.'88); the President's absolute immunity, Nixon v. Fitzgerald, 457 U.S. 731 (1982); a government official's qualified immunity, Mitchell v. Forsyth, 472 U.S. 511 (1985); intramilitary immunity based on the doctrine of Feres v. U.S., 340 U.S. 135 (1950), Lutz v. Secretary of the Air Force, 944 F.2d 1477 (9th Cir.'91); and a criminal defendant's double jeopardy claim, Abney v. U.S., 431 U.S. 651 (1977).
In Digital Equipment the Supreme Court observed that 'orders denying certain immunities are strong candidates for prompt appeal under section 1291.' 114 S.Ct. at 1998. This is because certain immunities are more likely to meet the third prong of the Cohen analysis: where the immunity guarantees a 'right not to stand trial,' that right may be 'irretrievably lost' if immediate review is not available. The Supreme Court in Digital Equipment hastened to add, however, that 'a party's ability to characterize a district court's decision as denying an irreparable 'right not to stand trial' altogether is [not] sufficient . . . for a collateral order appeal,' because virtually every right or procedural step that can be enforced by pretrial dismissal could be characterized as a right not to stand trial. 114 S.Ct. at 1998.
Admittedly, there is value . . . in triumphing before trial, rather than after it, regardless of the substance of the winning claim. But this truism is not to be confused with the quite distinct proposition that certain claims (because of the substance of the rights entailed, rather than the advantage to a litigant in winning his claim sooner) should be resolved before trial. Van Cauwenberghe, 486 U.S. at 524 (quoting U.S. v. MacDonald, 435 U.S. 850, 860 n.7 (1978)).
In claims of double jeopardy or official immunity, the judicial inquiry itself, rather than just a merits judgment, causes the disruption that the doctrine of immunity was designed to prevent. See, e.g., Abney, 431 U.S. at 659 (double jeopardy); Mitchell, 472 U.S. at 526 (qualified immunity); Lutz, 944 F.2d at 1481 (intramilitary immunity). The concept of qualified immunity is animated by concern about the burden of discovery and the need for government officials to act 'with independence and without fear of consequences.' Mitchell, 472 U.S. at 526. Immediate appeals are permitted because if officials were unable to obtain prompt review of denials of qualified immunity, the substance of the immunity would be lost. That concern is not the foundation of federal sovereign immunity. Suits that, for a technical reason, do not satisfy the strict requirements of statutes waiving sovereign immunity are no more fundamentally burdensome or disruptive than suits that do satisfy those requirements.
A motion for dismissal based on federal sovereign immunity is, therefore, strikingly similar to a motion for dismissal for failure to state a claim, see Fed.R.Civ.P. 12(b)(6), or a motion for summary judgment, see Fed.R.Civ.P. 56, neither of which is immediately appealable under the collateral order doctrine. All three types of orders give rise to similar efficiency concerns: Because the legal inquiry (whether the plaintiff's claim falls within the language of a statute or common law cause of action) is highly fact-specific, appellate resources would be squandered if appeals were heard before the relevant facts have been fully developed.
Section 1292(b) allows the district court to certify an order for interlocutory appeal if (1) the order involves a 'controlling question of law as to which there is substantial ground for difference of opinion,' and (2) 'an immediate appeal from the order may materially advance the ultimate termination of the litigation.'
Digital Equipment suggested two other guidelines as well: (1) immunities from trial stemming from public law are more likely to be immediately appealable than immunities derived from contract; and (2) immunities derived from the Constitution or statutes are more likely to be appealable because their importance is presumed. Id. at 2000, 2001. These guidelines are not conclusive. Federal sovereign immunity derives from public law, but it is not explicit in either the Constitution or statutes.