In Clajon Gas Co. v. Commissioner, the Tax Court held that Clajon Gas Company must use a 15-year recovery period to depreciate its natural gas gathering systems, instead of the seven-year recovery period Clajon originally used. The Tax Court reached this result by reading an ownership requirement into the phrase “used by” in the description of Asset Class 13.2. The decision in Clajon is noteworthy because it is at odds with the results reached by the United States Court of Appeals for the Tenth Circuit in Duke Energy Natural Gas Corp. v. Commissioner and the United States Court of Appeals for the Sixth Circuit in Saginaw Bay Pipeline Co. v. United States.Part I of this Note provides background on the natural gas industry and the legal framework relevant to the decision in Clajon. Part II sets out the facts of Clajon and explains the decision of the Tax Court. Finally, Part III analyzes four weaknesses in the Tax Court’s opinion: (A) ignoring a plain language interpretation; (B) not reflecting the realities of the natural gas industry; (C) treating similar depreciable assets differently; and (D) disregarding the doctrine of substance over form.