First Circuit: § 6213(a)’s 90-Day Tax Court Filing Deadline Is Nonjurisdictional but Mandatory and Not Equitably Tollable

1. Introduction

Kyick Holdings, LLC v. Commissioner of Internal Revenue Service (1st Cir. Aug. 17, 2026) arises from the IRS’s attempt to collect unpaid income taxes from an alleged transferee of assets. After concluding that transfers by Dwight Raymond and related entities were fraudulent, the IRS issued a notice of transferee liability to Kyick Holdings, LLC (“Kyick”). The notice was mailed to the address listed on Kyick’s most recent tax return, but it was returned “Unable to Forward.” Kyick ultimately learned of the notice and filed a Tax Court petition 143 days after mailing—well beyond the 90-day period in 26 U.S.C. § 6213(a).

The Tax Court dismissed for lack of jurisdiction on the prevailing view that § 6213(a)’s deadline is jurisdictional. On appeal, the First Circuit confronted three core issues: (i) whether the IRS used “reasonable diligence” in determining Kyick’s address; (ii) whether § 6213(a)’s deadline is jurisdictional; and (iii) if nonjurisdictional, whether it can be equitably tolled.

2. Summary of the Opinion

  • Notice/address: The IRS exercised reasonable diligence and properly mailed the notice to Kyick’s “last known address” (the address on its most recent return), satisfying I.R.C. §§ 6212(b) and 6901(g) and Treas. Reg. § 301.6212-2.
  • Jurisdiction: The 90-day filing deadline in I.R.C. § 6213(a) is nonjurisdictional under the Supreme Court’s “clear statement” framework (as developed in Boechler, P.C. v. Comm’r and related cases).
  • Equitable tolling: Even though nonjurisdictional, § 6213(a)’s deadline is mandatory and not subject to equitable tolling, principally in light of the Supreme Court’s analysis in Enbridge Energy, LP v. Nessel and the statutory scheme’s enumerated exceptions.

The court therefore affirmed the Tax Court’s dismissal on different grounds: not because the Tax Court lacked power, but because the (mandatory) filing deadline was missed and cannot be tolled.

3. Analysis

3.1. Precedents Cited

A. Standards of review and affirmance on alternative grounds

  • Schussel v. Werfel and Drake v. Comm’r supplied the familiar appellate posture for Tax Court appeals: factual findings are reviewed for clear error and legal rulings de novo. This framing mattered because the “last known address” determination turned on application of law (regulatory definition) to largely undisputed facts.
  • Helvering v. Pfeiffer and Ross v. Comm’r underwrote the First Circuit’s ability to affirm the Tax Court even though it rejected the Tax Court’s jurisdictional rationale. That doctrine is central to the outcome: the dismissal stands, but the “why” changes in a way that reshapes future litigation strategy.

B. “Last known address” and reasonable diligence

  • The court located “reasonable diligence” in non-binding, older circuit authority—explicitly citing: Mulder v. Comm’r, King v. Comm’r, Armstrong v. Comm’r, and Marks v. Comm’r. These cases historically required the IRS to use reasonable diligence to ascertain a taxpayer’s correct address when it knew or should have known an address was outdated.
  • The opinion also drew from more recent articulations of diligence inquiries: Gregory v. Comm’r (considering what IRS knew/should have known, including from its computer systems), Terrell v. Comm’r (importance of returned mail as a signal), and Gyorgy v. Comm’r (noting “tension” between older diligence caselaw and the later regulatory definition of “last known address”).
  • The Tax Court’s historical “term of art” approach was exemplified by Fernandez v. Comm’r, but the First Circuit emphasized that Treasury regulations now supply a controlling definition: the last known address is generally the address on the most recently filed and properly processed return absent “clear and concise” notice of change.
  • The court relied on the principle, stated in Marks v. Comm’r, that the IRS has “no duty to send duplicate notices to every single address” it knows. It also reiterated that a notice is valid even if not actually received if properly mailed to the last known address, citing Armstrong v. Comm’r and noting parallel First Circuit treatment in Niemela v. United States.
  • Alta Sierra Vista, Inc. v. Comm’r (as quoted via King v. Comm’r) supported the proposition that absent clear and concise notification, the IRS may rely on the address on the return.

C. Jurisdictional characterization and the “clear statement” turn

  • The key catalyst is Boechler, P.C. v. Comm’r, where the Supreme Court held a different Tax Code deadline nonjurisdictional and insisted on a “clear statement” from Congress before treating time bars as jurisdictional. The First Circuit treated Boechler as the intervening authority that undermines older “drive-by” jurisdictional holdings.
  • Wilkins v. United States and Riley v. Bondi
  • The opinion situated its interpretive method within the Supreme Court’s broader line: Henderson v. Shinseki (discipline in jurisdictional labeling), Arbaugh v. Y & H Corp. (clear statement rule), United States v. Wong (most time bars are nonjurisdictional; separation from jurisdictional grants is telling), Sebelius v. Auburn Reg’l Med. Ctr. and Zipes v. Trans World Airlines, Inc. (permissive phrasing not jurisdictional), MOAC Mall Holdings, LLC v. Transform Holdco LLC (plausibility of jurisdictional reading is not enough), and Harrow v. Dep’t of Def. (a limit can be “just a time limit”).
  • The First Circuit aligned with other post-Boechler appellate decisions—Culp v. Commissioner, Oquendo v. Comm’r, and Buller v. Comm’r—that read § 6213(a)’s deadline as nonjurisdictional. It distinguished or discounted contrary or older authority, including Organic Cannabis Found., LLC v. Comm’r, Tilden v. Comm’r, and the unpublished Allen v. Comm’r.
  • The IRS’s reliance on Supreme Court decisions Laing v. United States and U.S. ex rel. Girard Trust Co. v. Helvering was rejected as addressing prerequisites for deficiency proceedings generally (e.g., existence of a notice), not the jurisdictional status of the timing requirement.
  • For the First Circuit’s ability to depart from its own earlier precedent (Ferré v. Commissioner and subsequent unpublished First Circuit cases), the court invoked law-of-the-circuit principles from United States v. Rodríguez, with exceptions described in United States v. López and United States v. Pires.

D. Waiver/forfeiture and plain-error review in civil cases

  • The court carefully distinguished waiver and forfeiture, drawing on Mullane v. DOJ, Merrell Dow Pharms., Inc. v. Thompson, Freytag v. Comm’r, Morgan v. Sundance, Inc., United States v. Olano, Núñez-Pérez v. Escobar-Pabón, and United States v. Delgado-Sánchez.
  • It applied civil plain-error review as articulated in Triantos v. Guaetta & Benson, LLC, and explained why any Tax Court error could not be “plain” given inter-circuit conflict, citing United States v. Vázquez-Rosario and United States v. Crocco.
  • The court’s conclusion that Kyick forfeited equitable tolling (unlike the taxpayers in Culp v. Commissioner) rested on the differing litigation posture: Kyick had reason to raise tolling if it wanted it, and did not.

E. Equitable tolling rebutted by statutory design

  • The starting presumption—nonjurisdictional deadlines are presumptively tollable—was taken from Boechler, P.C. v. Comm’r and the foundational Irwin v. Dep’t of Veterans Affs.. The equitable tolling concept itself was described through Lozano v. Montoya Alvarez.
  • The framework for rebutting tolling focused on whether tolling is inconsistent with the statutory scheme, citing Arellano v. McDonough.
  • The decisive pivot was Enbridge Energy, LP v. Nessel (and its reliance on Nutraceutical Corp. v. Lambert): a nonjurisdictional rule can still be mandatory where Congress’s design shows an intent to foreclose open-ended equitable extensions.
  • The “enumerated exceptions” logic was anchored in United States v. Brockamp, while Kyick’s reliance on the shortness of the period drew analogies to Holland v. Florida and Boechler’s treatment of short deadlines.
  • On statutory interpretation sources, the court rejected legislative-history-based jurisdictional inferences with Shannon v. United States and the then-recent admonition in FS Credit Opportunities Corp. v. Saba Cap. Master Fund, Ltd..
  • The court noted, but did not hinge its result on, the Tax Court’s view in Hallmark Rsch. Collective v. Comm’r and clarified that post-Loper Bright Enters. v. Raimondo the Tax Court’s statutory interpretation does not bind Article III courts.
  • The opinion also cited the Eighth Circuit’s post-remand disposition in Boechler, P.C. v. Comm’r (8th Cir. Aug. 10, 2026) to illustrate the fact-specific nature of tolling even where available (though here the First Circuit held it unavailable under § 6213(a)).

3.2. Legal Reasoning

A. The address/notice holding: regulation-centered “last known address” with limited room for diligence doctrines

The court started from the governing statutory and regulatory scheme. Under I.R.C. § 6212 and § 6213, a deficiency notice must be mailed before assessment; for transferee liability, I.R.C. § 6901(g) makes notice sufficient if mailed to the transferee’s last known address. Treasury regulations now define “last known address” as “the address that appears on the taxpayer’s most recently filed and properly processed Federal tax return,” unless the IRS receives “clear and concise notification” of a different address (Treas. Reg. § 301.6212-2(a)).

Kyick conceded that the IRS used the address on its most recent return. That concession was pivotal: once the regulation’s definition is satisfied—and absent “clear and concise” change notification—Kyick’s “actual non-receipt” does not undermine validity. The court acknowledged older “reasonable diligence” caselaw but questioned its necessity post-regulation. Even assuming diligence is required, the IRS met it: it used the return address, confirmed it in its internal database, and had no obligation to mail duplicative notices to other addresses surfaced in an investigation.

B. The jurisdictional holding: applying Boechler’s “clear statement” rule to § 6213(a)

The court’s interpretive core is structural and textual. The first sentence of § 6213(a) states that the taxpayer “may” file within 90 days; it does not speak in jurisdictional terms. By contrast, the fourth sentence expressly uses jurisdictional language—limiting the Tax Court’s jurisdiction to “enjoin” or “order any refund” unless a timely petition has been filed. This juxtaposition mattered: Congress demonstrated it could write explicit jurisdictional conditions, but did not do so for the Tax Court’s deficiency-redetermination authority.

The court also emphasized separation: Congress placed the filing deadline apart from explicit jurisdictional limitations, a factor that United States v. Wong and related cases treat as a strong signal of nonjurisdictionality. Finally, the broader statutory context (e.g., I.R.C. § 6214(a) and § 6512(b)(1)) reinforces that Congress specifies jurisdiction when it intends to.

C. The “mandatory but non-tollable” holding: Enbridge Energy and the significance of enumerated exceptions

Having concluded the deadline is nonjurisdictional, the court confronted whether it is nevertheless immune from equitable tolling. Applying Enbridge Energy, LP v. Nessel, the court looked for “good reason” in the statutory text, structure, and context to conclude Congress did not want open-ended equitable extensions.

It found that reason in the statute’s design: § 6213(a) itself contains specific adjustments (150-day rule for notices addressed abroad; weekends/holidays rule; and the “last date specified” safe harbor). Congress also created other targeted suspensions and deadline adjustments throughout the Tax Code (including I.R.C. § 6213(e), § 6213(f), § 7451(b)(1), § 7508(a)(1)(C), § 7508A(a)(1), and the timely-mailing rule in § 7502(a)). This dense lattice of enumerated exceptions suggested that additional, judge-made equitable extensions would be “incongruent with the statutory scheme.”

The result is the opinion’s most consequential synthesis: § 6213(a)’s deadline is not jurisdictional, but it is mandatory and categorically not equitably tollable. The First Circuit acknowledged this diverges from Culp v. Commissioner, Buller v. Comm’r, and Oquendo v. Comm’r on tolling, attributing the divergence to those courts lacking the later guidance of Enbridge Energy, LP v. Nessel.

3.3. Impact

A. A new First Circuit rule for deficiency petitions: nonjurisdictional, but still fatal if raised

In the First Circuit, § 6213(a)’s 90-day deadline is no longer a “subject-matter jurisdiction” barrier. That reclassification has concrete procedural consequences: the IRS can potentially forfeit or waive the timeliness defense if not properly raised, and courts are no longer required to police timeliness sua sponte as a jurisdictional matter. But because the rule is “mandatory,” a properly raised timeliness objection still compels dismissal; the key difference is who must raise it and when.

B. A sharp limitation on taxpayer relief: no equitable tolling in deficiency cases

The court’s no-tolling holding is likely to be the more practically significant part of the precedent. It forecloses arguments that non-receipt, mailing mishaps, or other “extraordinary circumstances” can extend § 6213(a)’s period—except to the extent Congress already built targeted relief into the Code (combat zone relief, disaster relief, bankruptcy suspensions, timely-mailing rules, and the “last date specified” safe harbor).

C. Address litigation: reinforcing the primacy of the return address and the taxpayer’s duty to update

The opinion strengthens a regulation-centered approach to “last known address.” Taxpayers (including entities) that use multiple operational addresses must ensure the IRS receives “clear and concise notification” of changes; otherwise, the return address will control even if other addresses exist in IRS investigatory files.

D. Inter-circuit tension and Supreme Court gravity

The First Circuit now aligns with the Second, Third, and Sixth Circuits on nonjurisdictionality, but it departs on tolling. Because the court explicitly grounded its tolling analysis in a newly decided Supreme Court case (Enbridge Energy, LP v. Nessel), the decision increases the likelihood of further appellate convergence—or eventual Supreme Court review—on whether § 6213(a) is among the nonjurisdictional deadlines that are nevertheless categorically not tollable.

4. Complex Concepts Simplified

Transferee liability (I.R.C. § 6901)
A mechanism allowing the IRS to collect a taxpayer’s unpaid tax from someone who received the taxpayer’s assets (e.g., via a fraudulent transfer), up to certain limits.
Notice of deficiency / notice of transferee liability
The IRS’s formal notice that triggers the taxpayer’s right to seek pre-payment review in the Tax Court. Proper mailing to the “last known address” generally suffices even if not received.
“Last known address”
By regulation, usually the address on the most recently filed and properly processed federal tax return, unless the taxpayer clearly tells the IRS to use a different address.
Jurisdictional vs. claim-processing (procedural) rules
Jurisdictional rules define a court’s power and cannot be waived. Claim-processing rules regulate litigation steps; they can sometimes be forfeited or waived, but may still be mandatory if properly invoked.
Equitable tolling
A doctrine that can extend a filing deadline when a party acts diligently but extraordinary circumstances prevent timely filing—available only when Congress’s statute allows room for it.
Waiver vs. forfeiture; plain error
Waiver is intentional abandonment; forfeiture is failure to raise an argument. In civil cases, forfeited issues may be reviewed only under demanding plain-error standards.

5. Conclusion

Kyick Holdings, LLC v. Commissioner of Internal Revenue Service establishes a two-part First Circuit rule with immediate consequences for Tax Court practice: (1) § 6213(a)’s filing deadline is nonjurisdictional under the Supreme Court’s clear-statement approach, but (2) it is mandatory and categorically not subject to equitable tolling given the Tax Code’s tightly enumerated exceptions and the Supreme Court’s reasoning in Enbridge Energy, LP v. Nessel.

The decision also underscores a practical compliance lesson: the IRS may rely on the address on the most recent return absent clear change notice, and non-receipt alone will not rescue an untimely petition. In effect, the First Circuit modernizes the jurisdictional label while preserving strict timeliness in deficiency litigation—shifting the doctrine’s procedural mechanics without softening its outcome.