UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT RICHARD MOONEY, Nos. 23-3552 23-3683 Plaintiff – Appellee / D.C. No. Cross-Appellant, 2:20-cv-01030- LK v. ROLLER BEARING COMPANY OF AMERICA INC, a Delaware OPINION corporation,

Defendant – Appellant / Cross-Appellee.

Appeal from the United States District Court for the Western District of Washington Lauren J. King, District Judge, Presiding

Argued and Submitted February 14, 2025 Seattle, Washington

Filed June 5, 2025

Before: William A. Fletcher, Ronald M. Gould, and Jacqueline H. Nguyen, Circuit Judges. 2 MOONEY V. ROLLER BEARING CO. OF AMERICA

SUMMARY*

Prejudgment Interest

The panel affirmed the district court’s application of a fluctuating federal rate in calculating prejudgment interest in a case in which Richard Mooney, who prevailed at trial on his claims under the federal Family and Medical Leave Act and the Washington Family and Medical Leave Act, received an award of compensatory damages against his former employer Roller Bearing Company of America (RBC). The panel held that when a judgment is based on both state and federal claims, without any distinction between the claims, the district court has discretion to select a proper prejudgment interest rate. Here, the district court properly exercised its discretion in applying a fluctuating federal rate, as it found that rate was the most accurate way to compensate Mooney for the lost use of his wages between his first lost paycheck and the jury’s verdict. Further, while Mooney chose to file in state court, he did not contest RBC’s removal to federal court. More significantly, the district court found that Mooney asserted—and prevailed on—a federal claim that largely guided Mooney’s litigation strategy.

* This summary constitutes no part of the opinion of the court. It has been prepared by court staff for the convenience of the reader. MOONEY V. ROLLER BEARING CO. OF AMERICA 3

COUNSEL Mark B. Middaugh (argued), Middaugh Law PLLC, Seattle, Washington; Patrick J. Kang, Premier Law Group PLLC, Bellevue, Washington; for Plaintiff-Appellee. John J. White Jr. (argued) and Kevin B. Hansen, Peterson Russell Kelly Livengood PLLC, Bellevue, Washington; Blake Marks-Dias and Taryn M. Basauri, Corr Cronin LLP, Seattle, Washington; for Defendant-Appellant.

OPINION PER CURIAM:

Following a jury trial, Plaintiff Richard Mooney (“Mooney”) received an award of compensatory damages for his state and federal claims, without any distinction between the claims. The district court, which had both federal question and diversity jurisdiction, calculated prejudgment interest based on a fluctuating federal rate. Mooney appeals, arguing that the higher state rate should have applied. We hold that when, as here, the judgment is based equally on federal and state claims, the district court has discretion to decide which rate applies. Because the district court did not err in applying the federal rate, we affirm. I. Mooney sued his former employer, Defendant Roller Bearing Company of America (“RBC”), alleging violations 4 MOONEY V. ROLLER BEARING CO. OF AMERICA

of the Family and Medical Leave Act (“FMLA”) and the Washington Family and Medical Leave Act (“WFMLA”).1 Mooney’s lawsuit arose out of his termination, which he claimed was due to his age, depression, and his decision to take leave under the FMLA. RBC contended that Mooney’s termination was due to a reduction in