In Re US, 669 F.3d 1333

Panasonic challenged an IRS excise tax for importing products with ozone-depleting chemicals (ODCs) and sought a refund after contesting the government’s ODC testing method (PNNL).
The IRS conducted audits using PNNL’s testing on Panasonic’s imported phones; Panasonic paid taxes and penalties totaling about $9.9 million.
Panasonic sought discovery of PNNL testing data from other taxpayers to challenge the validity of the testing methodology.
The Court of Federal Claims ordered disclosure under the § 6103(h)(4)(B) exception to the confidentiality rule in § 6103(a).
The Federal Circuit granted mandamus to vacate the disclosure order, holding the § 6103(h)(4)(B) exception does not authorize such disclosure and that the order was a clear abuse of discretion.
The court addressed whether the “directly related” and “reflected on such return” language supports disclosure and emphasized taxpayer confidentiality and first-impression legal questions surrounding § 6103(h)(4)(B).

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether §6103(h)(4)(B) allows disclosure of third-party testing data.	Panasonic contends the item on the return is the ODC liability and its treatment; third-party testing is directly related.	United States argues the statute is not broad enough to permit such disclosure.	No; disclosure not authorized.
Meaning of ‘directly related’ and ‘reflected’ in §6103(h)(4)(B).	Panasonic argues the testing of third parties is directly related to the issue in the proceeding.	Government argues broader interpretation aligns with discovery goals.	The phrase is narrow; testing data not directly related to the return item.
Whether mandamus is appropriate to correct a lower-court order.	Panasonic seeks to prevent improper exposure of confidential information.	Government contends the lower court acted within discretion.	Yes; mandamus granted to vacate the order.

In re Seagate Technology, LLC, 497 F.3d 1360 (Fed. Cir. 2007) (mandamus relief for discovery orders involving privilege/confidentiality when imminent harm to privilege)
Regents of Univ. of Cal. v. U.S., 101 F.3d 1386 (Fed. Cir. 1996) (mandamus and privilege issues in discovery under All Writs Act)
Mohawk Indus., Inc. v. Carpenter, U.S. 130 S. Ct. 599 (2009) (privilege and confidentiality discussions in extraordinary relief)
Shell Petroleum, Inc. v. United States, 47 Fed. Cl. 812 (2000) (broad vs. narrow reading of 6103(h)(4)(B) guidance)
Vons Cos., Inc. v. United States, 51 Fed. Cl. 1 (2001) (legislative-history-based limits on 6103(h)(4)(B) disclosure)
United States v. Menasche, 347 U.S. 528 (1955) (statutory construction principle to give effect to every part of a statute)
Helvering v. San Joaquin Fruit & Inv. Co., 297 U.S. 496 (1936) (statutory interpretation principles for ordinary and natural meaning)
Bailey v. United States, 516 U.S. 137 (1995) (interpretation of statutory ambiguity and related rules)
Koons Buick Pontiac GMC, Inc. v. Nigh, 543 U.S. 50 (2004) (use of legislative history to resolve ambiguity)
Bates v. United States, 522 U.S. 23 (1997) (statutory interpretation principle noting selective language implies intentional limits)