On June 5, 2026, the Iowa Supreme Court issued a unanimous decision in Chickasaw County Board of Review v. Property Assessment Appeal Board, No. 25-1002 (Iowa Sup. Ct. June 5, 2026). This ruling resolves a long-standing property tax classification dispute regarding commercial bulk fuel storage mechanisms. The Court affirmed that eleven 90,000-gallon propane fuel tanks owned by an agricultural cooperative are unattached "equipment" under Iowa Code section 427A.1(1)(d), rather than taxable real property "improvements" under section 427A.1(1)(c). Crucially, in reaching this conclusion the Court enacted a major precedential shift by overruling long-standing case law on tax canons, declaring that courts will no longer lean on traditional presumptions for or against the taxpayer and will instead interpret the tax code according to its plain language.
Background Facts
Growmark, Inc., an agricultural cooperative providing retail and business products to farming communities, operates a prominent fuel distribution terminal in New Hampton, Iowa. Growmark acquired the site in December 2016 for $2 million, an acquisition that included eleven 90,000-gallon propane fuel storage tanks. These tanks hold bulk propane on-site until it can be distributed to retail operations and agricultural customers, primarily area farmers.
The tanks in question rest on top of concrete saddle foundations. Importantly, these tanks are held completely in place on these saddles by gravity alone; they are not bolted, welded, or otherwise physically fastened to the foundation. Although the tanks have remained at the New Hampton distribution site since 1977, they are entirely movable. If operations were to relocate, each tank can be physically disconnected from the distribution pipes and transported to a different parcel of land.
The conflict in this case arose in 2023 when the Chickasaw County assessor evaluated the New Hampton facility and valued the eleven tanks at $1,959,500. The assessor incorporated this valuation into the real property tax assessment, a determination subsequently upheld by the Chickasaw County Board of Review. The Board of Review argued that, as the tanks store fuel rather than actively process it, they function essentially as warehouses and must be taxed as real property "improvements" under Iowa Code § 427A.1(1)(c).
Growmark filed a challenge to the assessment with the state Property Assessment Appeal Board (PAAB), pointing primarily to the 2022 Iowa Court of Appeals case McDermott Propane, LLC v. Board of Review, 975 N.W.2d 31, which held that similarly situated 30,000-gallon propane tanks were nontaxable equipment. The PAAB granted summary judgment in favor of Growmark, ruling that the tanks were unattached equipment and ordering their removal from the 2023 property assessment.
District Court Action
In response to the PAAB’s judgment, the Board of Review filed a petition for judicial review in the Iowa District Court for Chickasaw County. Growmark joined the suit as an intervenor. On review, the district court affirmed the administrative ruling, determining that the PAAB had correctly applied the statutory distinctions between real estate improvements and business equipment, and properly distinguished the case from older, non-binding tax guidelines. The Board subsequently appealed the court’s ruling to the Iowa Supreme Court, which retained the case for final disposition.
Supreme Court Rationale
The Court held that unattached propane tanks are exempt from property tax as commercial equipment under Iowa Code § 427A.1(1)(d) rather than taxable real estate improvements, rejecting the Board of Review's functional "storage-versus-processing" test. In reaching this decision, the Court reviewed the administrative legal conclusions without deference and established significant new precedent by declaring that tax statutes must be interpreted strictly according to their plain text instead of applying any presumptions in favor of or against the taxpayer.
Standard of Review & Administrative Deference
The Court first observed that the Iowa Code does not vest the PAAB with clear statutory authority to interpret terms like "equipment" or "improvement." Thus, the PAAB's legal conclusions are reviewed for errors of law without deference. Additionally, the Court rejected the Review Board’s argument that it should defer to a selection of Department of Revenue (DOR) materials classifying industrial machinery and equipment, such as the 1977 and 1984 Valuation Guides, an internal 1985 memo, and a 1986 technical bulletin. The Court reasoned that, while the DOR does have the statutory authority to interpret section 427A.1, Iowa courts will only defer to agency interpretations that are (1) promulgated as rules through the public rulemaking process; or (2) made in an agency action that is the direct basis of a contested case. Because these internal guidance manuals were never formally promulgated as administrative rules through public rulemaking processes, and the case does not involve judicial review of direct DOR action, they were not entitled to the Court’s deference. In the absence of deference, the Court found these materials unsupportive of the Board of Review’s present claim. They lacked any statutory analysis and were made well before major legislative updates to the tax code, including the 1987 repeal of all personal property taxes in Iowa. They failed to accurately reflect the current state tax regime.
Overruling Non-Textual Canons of Construction in Tax Statutes
Though noted as merely a “housekeeping matter,” the Court marked a significant jurisprudential shift in its analysis by explicitly overruling prior case law regarding how tax statutes are interpreted. Historically, Iowa courts applied a dual canon: construing tax provisions levying taxes liberally in favor of the taxpayer, but construing tax exemptions strictly against the taxpayer. The Court observed that these judicially constructed rules often conflict with and lack statutory backing in the Iowa Code. Additionally, justifications for these interpretive principles have been rooted in policy considerations, which the Court emphasized are more appropriately addressed by the legislature. Moving forward, Iowa courts will construe tax statutes according to their ordinary, plain meaning, applying the same interpretive principles used for any other legislative statute.
Improvement vs. Equipment
Turning to the core of Iowa Code § 427A.1, the Court highlighted that the statute creates an absolute divide between taxable real property and exempt personal property. Under paragraph (c), "buildings, structures, or improvements" are taxable real property whether attached to a foundation or not. Under paragraph (d), "equipment and machinery" are only taxable if they are physically attached to a paragraph (c) structure. Because chapter 427A does not explicitly define these terms, the Court adopted their ordinary meanings, as found in Black’s Law Dictionary and supported by Iowa case law:
- An "improvement" is a relatively permanent addition to land that enhances its baseline utility or appearance and acts as an unremovable fixture.
- "Equipment" consists of tangible implements used to execute a specific activity, especially a commercial operation.
In its appeal, the Board of Review relied extensively on the case StateLine Coop. v. Iowa Prop. Assessment Appeal Bd., 958 N.W.2d 807, 809 (Iowa 2021), for the proposition that any asset used for storage (such as a tank, silo, or warehouse) is a taxable improvement, while processing assets are exempt machinery. The Court corrected this interpretation, explaining that the storage-versus-processing test in StateLine applied strictly to categorizing assets within a narrow class of manufacturing equipment exempted from taxation under paragraph (e). Paragraph (d) is a broad exemption category that covers equipment in both commercial and manufacturing activities, while paragraph (e) applies only to equipment specifically “used in manufacturing establishments.” Unlike StateLine, the primary question in this case is whether an asset is an improvement under paragraph (c) or equipment under paragraph (d). The fact that such an asset functions as storage does not automatically classify it as a real estate improvement.
The Court concluded that the tanks are commercial business equipment rather than permanent land fixtures. They sit unattached on concrete saddles, held solely in place by gravity. Their structural components can be disconnected and completely disassembled without causing any damage to the surrounding land or the supporting base foundations. The tanks squarely fit under the ordinary definition of equipment as implements used for a specific commercial purpose—propane storage and distribution. Accordingly, as physically unattached equipment, the Court held that these tanks fall outside the definition of taxable real property and should be exempt from assessment.
Observations
A Level Playing Field in Tax Disputes
Chickasaw County fundamentally changes the rules of engagement for courts in property tax disputes. The Court overhauled decades-long doctrines of Iowa tax statute construction, opting instead to treat statutory ambiguities in tax law the same as any other statutory disagreement. With roots in English common law, these canons are favorably cited by the United States Supreme Court[i] and frequently applied across U.S. jurisdictions. Of course, no canon is absolute, and some jurisdictions expressly balance or reinforce these canons by statute.[ii] Notably, Iowa has no such statutory language. The Court's holding in Chickasaw County is driven principally by an apparent conflict between these traditional canons and Iowa Code § 4.2, which explicitly directs courts to construe statutory provisions liberally “with a view to promote its objects and assist the parties in obtaining justice.”
In the wake of the Chickasaw County decision, future disputes over property tax classifications, exemptions, or assessments will be interpreted in the same manner as other sections of the Iowa Code. Taxpayers can no longer rely on a protective interpretive tilt when a tax-levying statute is vague—but conversely, the government can no longer appeal to a presumption against the taxpayer on exemptions.
Financial Relief for Agribusiness Infrastructure
In confirming that unattached storage equipment is exempt from real property assessments, the Iowa Supreme Court has solidified a path for cooperatives and agricultural retailers towards relief from substantial property tax liabilities. In this case alone, excluding the eleven propane tanks from real property lists spared Growmark from paying annual taxes on nearly $2 million in assessed value. Chickasaw County helps to establish a predictable environment for investing in agricultural infrastructure, including bulk fuel terminals, fertilizer storage tanks, and related logistical equipment across Iowa.
Uniformity in Assessments and the Demise of the 30,000-Gallon Limit
Following the 2022 appellate ruling in McDermott Propane, many county assessors across Iowa stopped taxing propane tanks with a capacity of 30,000 gallons or less, but continued to assess larger commercial tanks. ChickasawCounty firmly rejects any arbitrary size-based distinction. The statutory test for taxability is based on physical attachment and commercial purpose rather than capacity. Agribusinesses with large-scale storage tanks should audit their property tax assessments to ensure counties are not inaccurately assessing any unattached personal property assets.
[i] Gould v. Gould, 245 U.S. 151, 153 (1917); see also United States v. Merriam, 263 U.S. 179, 188 (1923).
[ii] See, e.g., A.C.A. § 26-18-313 (statutes imposing taxes must be strictly construed to limit the imposition of taxes, and any well-founded doubt regarding their meaning must be resolved against the tax); Nev. Rev. Stat. Ann. § 372.815 (tax imposition provisions are exclusive and cannot be extended to transactions not expressly made taxable); Fla. Stat. § 203.04 (tax exemptions or exceptions cannot be implied and must be clearly and specifically expressed).