Carol Engen v. United States

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
CAROL ENGEN,
Plaintiff-Appellant
v.
UNITED STATES,
Defendant-Appellee
______________________
2025-1088
______________________
Appeal from the United States Court of Federal
Claims in No. 1:24-cv-00237-LAS, Senior Judge Loren A.
Smith.
______________________
Decided: September 9, 2025
______________________
CAROL E NGEN, Buckeye, AZ, pro se.
RICHARD L. P ARKER, Tax Division, United States
Department of Justice, Washington, DC, for defendant-
appellee. Also represented by CLINT CARPENTER .
______________________
Before CHEN, L INN, and HUGHES , Circuit Judges.
P ER CURIAM .
Case: 25-1088 Document: 32 Page: 1 Filed: 09/09/2025

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ENGEN v. US 2
Carol Engen (“Engen”) appeals from a judgment of the
U.S. Court of Federal Claims, dismissing her tax refund
claims under Rule 12(b)(6) of the Rules of the Court of
Federal Claims (“RCFC”).1 See Engen v. United States,
172 Fed. Cl. 651 (2024). We have jurisdiction pursuant to
28 U.S.C. § 1295(a)(3). Since we write for the parties, we
assume familiarity with the record. For the reasons that
follow, we affirm.
D ISCUSSION
The Court of Federal Claims concluded that Engen
failed to state a claim because her tax refund claims were
barred as a matter of res judicata based on a prior deci-
sion in United States v. Engen, No. C18-712 RSM, 2021
WL 4391222 (W.D. Wash. Sept. 24, 2021) (“Dist. Ct.
Order”), aff’d, No. 21-35804, 2023 WL 2556858 (9th Cir.
Mar. 17, 2023) (“Memorandum”). Because the term “res
judicata” encompasses elements of both claim preclusion
and issue preclusion and the Court of Federal Claims
applied the elements of claim preclusion to the facts of
this case, we use the term claim preclusion herein for
clarity.
Claim preclusion applies where “(1) the prior decision
was rendered by a forum with competent jurisdiction;
(2) the prior decision was a final decision on the merits;
and (3) the same cause of action and the same parties or
their privies were involved in both cases.” Carson v. Dep’t
of Energy, 398 F.3d 1369, 1375 (Fed. Cir. 2005). When
claim preclusion is applied against a defendant, the third
1 Because Engen has not appealed the denial of her
motion under RCFC 60(b), we need not and do not ad-
dress arguments raised in that motion and only cursorily
presented on appeal. See Becton Dickinson & Co. v. C.R.
Bard, Inc., 922 F.2d 792, 800 (Fed. Cir. 1990).
Case: 25-1088 Document: 32 Page: 2 Filed: 09/09/2025

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ENGEN v. US 3
element is met where a defendant in a first proceeding
later raises claims amounting to a “collateral attack on
the first judgment” such that “successful prosecution of
the second action would nullify the initial judgment or
would impair rights established in the initial action.”
First Mortg. Corp. v. United States, 961 F.3d 1331, 1339–
40 (Fed. Cir. 2020).
Engen argues that none of the elements of claim pre-
clusion are met in her case and the Court of Federal
Claims erred by holding otherwise. We disagree with her
arguments on all three elements.
As to the first element, the district court was a court
of competent jurisdiction. Congress has authorized the
Attorney General to bring—and the district courts to
hear—civil actions to enforce liens of the United States in
cases involving “a refusal . . . to pay any tax, or to dis-
charge any liability in respect thereof.” 26 U.S.C.
§ 7403(a). Further, we reject Engen’s argument that the
district court lacked jurisdiction specifically over the
government’s penalty claims. The Internal Revenue Code
provides that liens for failure to pay taxes may encompass
penalties and that penalties “shall be assessed, collected,
and paid in the same manner as taxes.” Id. § 6665(a)(1);
see also id. §§66321, 6671(a).
Regarding the second element, the district court’s
grant of summary judgment was a decision on the merits
and not, as Engen contends, a default judgment. See Dist.
Ct. Order¸ 2021 WL 4391222, at *2–3 (noting that Engen
responded to the government’s motion for summary
judgment); see also Memorandum, 2023 WL 2556858,
at *1 (affirming grant of summary judgment because
“Engen failed to raise a genuine dispute of material fact
as to whether the tax and penalty assessments were
invalid”). The district court reviewed the record, rejected
Engen’s arguments, and held that the Government was
entitled to judgment on its claims as a matter of law.
Case: 25-1088 Document: 32 Page: 3 Filed: 09/09/2025

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ENGEN v. US 4
That decision was affirmed on appeal and represented a
final decision on the merits for purposes claim preclusion.
See Mpoyo v. Litton Electro-Optical Sys., 430 F.3d 985,
988 (9th Cir. 2005) (holding that a summary judgment
dismissal is “considered a decision on the merits for [claim
preclusion] purposes”).
The third element is also met. Engen’s suit involves
the same parties as the district court proceedings. See
Appellant’s Informal Br. 20. Engen’s claims against the
Government seek refunds for payments made pursuant to
the district court’s judgment in favor of the United States.
Her claims seek to impair, if not nullify, the rights estab-
lished by the district court’s assessment of her liability
and thus represent a clear attempt to relitigate the earlier
suit.
For these reasons, claim preclusion bars Engen’s
cause of action. See First Mortg. Corp., 961 F.3d at 1339–
41 (holding that claim preclusion bars defendants in a
first action from later raising claims amounting to “a
collateral attack on the first judgment”). Because Engen
is precluded from obtaining the relief she requests, dis-
missal of her case by the Court of Federal Claims was
proper. See id. at 1338.
We have considered Engen’s other arguments but find
them unpersuasive. Accordingly, the judgment of the
U.S. Court of Federal Claims is affirmed.
AFFIRMED
COSTS
Each of the parties shall bear their own costs.
Case: 25-1088 Document: 32 Page: 4 Filed: 09/09/2025

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