Recommended Article on Constitutional Interpretation Applicable to Statutory Interpretation and Loper Bright (8/22/26)

Yesterday and today, I have been thinking about an article that implicates some of the interpretive issues I have been writing on post-Loper Bright. The article is: John O. McGinnis & Mike Rappaport, Originalism’s Better Meaning (Law & Liberty 8/13/26), here. Although developed in the context of constitutional interpretation and originalism, the article makes some points that seem to me applicable to statutory interpretation more broadly than the originalism spin.

First, the authors define the difference between interpretation and construction:

Interpretation is the process of determining the meaning of a constitutional provision. Construction begins only when that meaning is deemed indeterminate—that is, when it is thought to run out—and the decision must be made on grounds other than the provision’s original meaning.

I would restate that for statutory interpretation as follows (with changes in bold):

Statutory interpretation is the process of determining the meaning of a statutory provision. Statutory construction begins only when that meaning is deemed indeterminate—that is, when it is thought to run out—and the decision must be made on grounds other than the provision’s meaning as determined by statutory interpretation.

In these constructs, Chevron deference was construction rather than interpretation because it applied only when the meaning could not be determined and applied as a default rule to resolve cases before the courts without regard to the indeterminate meaning of the statute.

One interesting construct the authors deploy in the article is the “51-49 rule” which permits the “best” interpretation to be determined by the preponderance of the evidence standard (applying fact-finding concepts to a state of statutory interpretive ambiguity). In this construct, interpretation of a constitution (or statute) requires a confidence level for an interpretation to be at least 51%. The construction zone is between 50.9999% and 49.0001% where some default rule is required to resolve cases.

(Caveat: I don’t think that is a realistic range in statutory interpretation (or fact-finding for that matter); can anyone meaningfully distinguish between an interpretation that is 49.9% and one that is 50.1%?; but let’s just accept that construct for now; for my discussion of such ranges in valuation context, see John A. Townsend, Burden of Proof in Tax Cases: Valuation and Ranges—An Update, 73 Tax Lawyer 389 (2020).)

First Circuit Holds that the Time Period to File Petition in § 6213(a) is NonJurisdictional But Mandatory, Hence No Equitable Tolling (8/19/26; 8/20/26)

In Kyick Holdings, LLC v. Commissioner, ___ F.4th ___ (1st Cir. 2026), CA1 here and GS here [to come], the Court held that

1. The IRS properly sent the notice to the taxpayer’s last known address. This is the less exciting holding, but I will address it below in my Comment #2.

2. Section 6213(a)’s timely filing requirements are not jurisdictional. (Caution on this label “jurisdictional” though, as I note below.)

3. As a matter of statutory interpretation § 6213(a)’s timely filing requirements are “mandatory,” meaning that the periods to file the petition is not subject to equitable tolling. This latter holding has the same practical effect as would have applied if the Court had agreed with the consensus holdings in the Courts of Appeals that § 6213(a)’s time periods were jurisdictional.

The key holdings for purposes of this blog are ## 2 & 3, although they are not outcome-determinative in terms of the holdings of other Circuit Courts of Appeals. That is because regardless of whether a Court bases its outcome on jurisdiction or a mandatory analysis, the result is the same in denying the availability of equitable tolling.

For that reason, I worry whether courts futzing around with “jurisdiction” in this context is meaningful. Courts could just go to the heart of the disposition that the time periods are mandatory. In many cases, courts are just writing at length about jurisdiction which has some esoterica when mandatory should do.

Added 8/20/26 3:25pm: For a different outcome see Maniktala v. Commissioner, ___ F.4th ___ (8th Cir. 8/11/26), CA8 here and GS here, allowing equitable estoppel for time deadlines in § 6213(a) based on holdings that (i) § 6213(a) is nonjurisdictional (consistent with Kyick) but (ii) the § 6213(a) deadlines are not mandatory (inconsistent with Kyick). It appears that there is a clear conflict in the Circuits on the statutory interpretation issue which is often a substantial basis for granting a petition for writ of certorari. I should note that, in effect, Maniktala seems to be based on the Eighth Circuit's application of the default rule allowing equitable estoppel in a case where the court cannot determine the statutory meaning (in interpretive equipoise), whereas Kyick is based on an interpretation of the statute where it could it could determine the statutory meaning. Although an agency interpretation that might have qualified for Chevron deference (i.e., a Treasury interpretive regulation) is not in issue, this split does highlight one of the central fanciful notions of Loper Bright that courts can always interpret statutes to reach the best interpretation without the need for default rules for decision.

Other JAT Comments:

District Court Invalidates and Vacates Listed Transaction Reporting Regulation (4/18/26)

In Drake Plastics Ltd. Co. v. IRS, ___ F. Supp. 3d ___ (S.D. Tex. 4/15/26), CL here, and GS here, the court (Judge Lee Rosenthal) considered APA claims of invalidity of the regulations determinations of “transactions of interest” and “listed transactions” for micro-captive insurance companies (from the conclusion):

          The court grants in part the plaintiffs’ motion for summary judgment and a permanent injunction, (Docket Entry No. 58), and grants in part the defendants’ cross-motion for summary judgment, (Docket Entry No. 63). The defendants (1) appropriately designated micro-captive transactions as transactions of interest through 26 C.F.R. § 1.6011-11; but (2) exceeded their statutory authority in designating micro-captive transactions as listed transactions through 26 C.F.R. § 1.6011-10. The court declares unlawful 26 C.F.R. § 1.6011-10 and vacates it. The case is remanded to the Department of the Treasury and the Internal Revenue Service for further agency action consistent with this opinion.

          The vacatur is stayed until May 1, 2026, to avoid taxpayer confusion on Tax Day. Cf. Purcell v. Gonzalez, 549 U.S. 1, 4–5 (2006) (“Court orders . . . can themselves result in . . . confusion . . . .”). Final judgment is entered separately.

I am not sure what the last paragraph stay is about, but I do understand the holdings in the first paragraph.

The court’s holding turns upon interpretation of the statutory requirement that "transactions of interest" have the “potential” for tax avoidance but that “listed transactions” that have tax avoidance, at least presumptive tax avoidance, rather than just the potential for tax avoidance. The court reasoned that the IRS did not adequately explain microcaptive arrangements identified in the "listed transaction" regulation.

Judge Rosenthal is a very good judge, so I respect her analysis, even though I am not convinced that it is correct.

Comments on Highly Recommended Article Extending Skidmore "Deference" Approved in Loper Bright (3/7/26; 3/8/26)

I have just read a great article: Mitchell Zaic, Note: The Skidmore Compromise: Interpreting Skidmore as a Tiebreaker to Preserve Judicial Wisdom in the Era of Loper Bright, 110 Minn. L. Rev. 1535 (2026), here, and post some thoughts on the article and on Skidmore (Skidmore v. Swift & Co., 323 US 134 (1944), here).

First, I acknowledge Mr. Zaic has published an exceptional work with substantial research and creative thought after Loper Bright Ent. v. Raimondo, 603 U.S. 369 (2024), SC here (Preliminary Print), which overruled so-called Chevron deference. Chevron U.S.A. Inc. v. Nat. Res. Def. Council, Inc., 467 U.S. 837 (1984), GS here. Mr. Zaic says in the asterisk for his name: “Writing this piece has been one of the great privileges of my life.” He has also privileged readers of the article.

Mr. Zaic states his thesis in these two excerpts (pp. 1356 and 1569):

This interpretation of Skidmore would only be used by interpreters when judges are faced with interpretive ties that have no other method of resolution. Only then can judges resort to applying the agency's interpretation. This method of interpreting Skidmore ensures that agency interpretations never overrule the best meaning of the statute, instead facilitating the judge in his or her interpretive quest. In addition, the tiebreaker continues the long tradition of respect for agency interpretations beyond that of the typical litigant.

* * * *

Where competing interpretations are at equipoise to an interpreter, courts should resolve conflicts in the agency's favor so long as the agency's reasoning is valid, thorough and its interpretation arises from experience and informed judgment.

Bottom line, Mr. Zaic argues that, in a state of statutory interpretive equipoise, a court needs—indeed, must—apply a default rule to decide the case. The default rule in a case where a regulated party opposes an agency interpretation is that the court should default to the agency interpretation. Mr. Zaic gets to his conclusion through a process of reasoning.

My previous Chevron research indicates that Chevron worked in equipoise (without necessarily the qualifiers at the end of Mr. Zic's last sentence). Chevron was supposed to apply only where, after vigorous statutory interpretation (Chevron fn. 9), the statutory text was still ambiguous—in equipoise—where the court could not determine which of two or more interpretations within the zone of ambiguity was the best interpretation.

Chevron, Loper Bright, and Statutory Ambiguity (1/8/26; 1/9/26)

Added 1/9/26 9:00pm: I would really appreciate readers notifying me of any case(s) they have read where the court said that it determined the best interpretation and nevertheless deferred under Chevron to a not best agency interpretation. Please respond either by comment or by email to me at jack@tjtaxlaw.com.

I start with two opposing statements:

“Chevron requires a federal court to accept the agency's construction of the statute, even if the agency's reading differs from what the court believes is the best statutory interpretation.” National Cable & Telecommunications Assn. v. Brand X Internet Services, 545 U.S. 967, 980 (2005) (Thomas, J. for the Court).

ChatGPT’s response to the following question: “Can you find me a United States case where the court determined the best interpretation of a statute but nevertheless applied Chevron to defer to a not best agency interpretation?”:

No United States case is identified in the provided search results where a court explicitly determined the best interpretation of a statute but nevertheless applied Chevron deference to a non-best agency interpretation. * * * * The results highlight Chevron's requirement for courts to defer to reasonable agency views of ambiguous statutes but provide no instance where a court labeled its own view "best" yet deferred anyway, likely because such language would contradict Step One's mandate to enforce unambiguous meanings.”

[JAT Note in support of ChatGPT’s response: I have read many Chevron cases and do not recall that a court ever said it had determined than interpretation other than the agency's was best but deferred to the agency interpretation. At an anecdotal level, I read cases identified by other scholars as Chevron cases and found that not one of the cases said the court determined the best interpretation was other than the agency interpretation and nevertheless deferred to the agency interpretation. See Is Chevron on Life Support; Does It Matter? (Federal Tax Procedure Blog 4/2/22; 4/3/22), here (focus on Category 5); and  Chevron Step Two Reasonableness and Agency Best Interpretations in Courts of Appeals (Federal Tax Procedure Blog 2/9/23), here (again focus on category 5). In not of those cases did a court state or fairly imply that it had determined a best interpretation and was deferring to the agency interpretation instead. Not one.]

I propose that (i) Chevron deference, properly applied, was a tie-breaker rule when a court found statutory text ambiguous as required to get past Step One (meaning that the court could not determine the best interpretation) and (ii) that Loper Bright’s rejection of Chevron deference leaves courts without guidance to resolve ambiguous statutory text. Of course, the phenomenon of statutory interpretive ambiguity is not unique to agency interpretations of statutes they administer, but at least Chevron offered a consistent and, in a sense, principled way to resolve ambiguity to reach a decision in the case at hand.

Statutory Interpretation as a Continuum and Equipoise in the Continuum (12/20/25)

Continuing on my exploration of AI (I am still a novice), I asked several AI tools about ambiguity and continuum of confidence in statutory interpretation as a way to think about when ambiguity does not permit a court to determine the best interpretation to the required confidence level (in percentages say 51%, 60%, 67%, etc.). I offer here the best of the AI outcomes (from MS CoPilot) with both text and footnotes indented and then make a few comments.

Below is a polished, law‑review‑style Part II that builds naturally on your Part I. It is structured, argumentative, and footnoted in proper Bluebook form. If you want, I can later add subparts (A, B, C), case studies, or integrate it into a full article.

II. The Ambiguity Continuum in Judicial Practice

Courts frequently describe statutory text as either “clear” or “ambiguous,” but this binary framing masks the far more nuanced reality of interpretive practice. In actual adjudication, judges encounter not a dichotomy but a continuum of ambiguity, ranging from provisions whose meaning is overwhelmingly apparent to those whose linguistic indeterminacy leaves multiple interpretations equally plausible.¹ Judicial methodology—whether textualist, purposivist, or something else—does not eliminate this continuum; rather, it structures how judges navigate it. Understanding this spectrum is essential to explaining why interpretive disputes persist even when judges purport to apply the same tools.

A. The Myth of Binary Clarity

The conventional judicial rhetoric of “plain meaning” suggests that statutory clarity is a threshold condition: either the text speaks for itself or it does not.² Yet linguistic theory and empirical studies of judicial behavior demonstrate that clarity is rarely self‑evident.³ Even seemingly straightforward provisions often contain latent ambiguities that become visible only when applied to specific factual contexts.⁴ As Justice Kagan has observed, “we’re all textualists now,” but textualism itself requires judges to make fine‑grained judgments about how much clarity is enough.⁵

These judgments are not mechanical. They depend on context, background assumptions, and the judge’s own interpretive priors.⁶ A provision may appear clear to one judge because she reads it against a particular linguistic or structural backdrop, while another judge—equally committed to textual fidelity—may find the same provision ambiguous.⁷ The very act of declaring a statute “clear” is thus an interpretive conclusion, not an objective fact.

B. Degrees of Ambiguity and the Use of Interpretive Tools

As ambiguity increases along the continuum, courts predictably rely more heavily on interpretive tools to resolve uncertainty. Textual canons, for example, function as probability‑adjusting heuristics: they shift the likelihood of one interpretation over another by appealing to linguistic conventions, structural coherence, or background norms.⁸ Legislative history, when used, serves a similar function by providing additional evidence about how Congress likely understood the statutory language.⁹ Substantive canons—such as the rule of lenity, the presumption against retroactivity, or federalism clear‑statement rules—operate at the far end of the continuum, where ambiguity is so deep that ordinary interpretive tools fail to produce a dominant reading.¹⁰

Tax Court on Default Rules in Statutory Interpretation-Herein Also of Chevron, Loper Bright and APA § 706(2(A) (11/14/25)

In Apache Corp. v. Commissioner, 165 T.C. 210 (11/1325), reviewed opinion, the Court addressed the momentous (to some) issue of whether a taxpayer electing not to carryback some categories of net operating losses (NOLs) can reserve in the election to carryback other categories of NOLs. The opinions in Apache may be viewed on the Tax Court Docket Sheet for Case # 25984-22, here, at #56, on my Google Drive here, in the Tax Court Preliminary Print here, on GS here, and on TN here.  I must say that I have neither worried nor lost sleep over that issue, either before or after this opinion. As respects the issue actually decided in Apache, I am agnostic which may be an admission that I have not really dug deeply into the issue. So, I don’t propose here to deal with the merits of the issue decided.

I want to address the methodology in reaching the majority opinion and Judge Buch’s concurring opinion.

Judge Buch’s concurring opinion (Slip Op. 22-23) is very short. If I may summarize a very short opinion:

(i)          the statutory text is inconclusive on the competing interpretations which are equally plausible, phenomenon I describe as statutory ambiguity where a best interpretation cannot be made; and

(ii)        where the statute is ambiguous, courts are “inclined to rely on the traditional canon that construes revenue-raising laws against their drafter.”

The majority determines that the statutory text is not ambiguous but then says (Slip Op. 18-19) that the default rule Judge Buch relies on should carry the day even if the text were ambiguous (calling it a “tiebreaking principle"). As stated, this supposed principle, sometimes stated as a canon or maxim of interpretation, operates like the rule of lenity that construes criminal statutes in favor of a defendant, which is a default rule in cases of ambiguity. See e.g., Ryan D. Doerfler, The "Ambiguity" Fallacy, 88 Geo. Wash. L. Rev. 1110, 1116 (2020) (referring to Chevron and lenity as default rules); Intisar A. Rabb, The Appellate Rule of Lenity: Responding to Abbe R. Gluck & Richard A. Posner, Statutory Interpretation on the Bench: A Survey of Forty-Two Judges on the Federal Courts of Appeals, 131 Harv. L. Rev. 179, 194 n. 77 (2018) (Same re lenity).

That interpretive methodology in ambiguity is a default rule similar to the Chevron default rule prior to Chevron’s demise in Loper Bright. As readers of this blog and observers in general know, Loper Bright overruled Chevron and thus the Chevron default rule does not apply in a state of ambiguity as between two or more interpretations, one of which is an agency interpretation qualifying for Chevron deference (generally notice and comment interpretive regulations).

Eighth Circuit Applies First Sec. Bank Limitation to § 482 Intangibles Allocation Despite the Commensurate with Income Standard Enacted in 1986 (10/2/25)

I recently wrote on the 3M case pending in the 8^th Circuit involving the issue of whether the commensurate with income standard in § 482 enacted in 1986 permits the IRS to use § 482 to allocate royalty income to 3M for intangibles it transferred to a Brazilian affiliate in excess of the amount of royalty income permitted by Brazilian law. The full text of the commensurate with income standard  enacted in 1986 is: “In the case of any transfer (or license) of intangible property (within the meaning of section 367(d)(4)), the income with respect to such transfer or license shall be commensurate with the income attributable to the intangible.” See Loper Bright’s Motivated Mistreatment of Statutory Ambiguity and Best Interpretations (Federal Tax Procedure Blog 8/28/25), here.

In 3M Company v. Commissioner, 154 F.4th 574 (8th Cir. 10/1/25), here and GS here, the Court held that the IRS could not use § 482's commensurate with income standard to tax a related party affiliate's (3M's)  income on the transfer of intangibles in excess of legal limits permitted by law applying to the party receiving and exploiting the intangibles transferred to it.

I think it might be helpful to illustrate the issue in a simple examples. I start with an example where no legal prohibition is involved: Suppose intangible property in an open market would have commanded a royalty of 10% in an unrelated party transaction (which I will call the fair market value (“FMV”) royalty). But, in a related party transaction, the U.S. party transferring intangibles to the foreign affiliate charged the foreign affiliate a royalty of 5%. The foreign affiliate earns extra income over what it would have earned if it paid the FMV 10% royalty. This example is a classic instance where the commensurate with income standard enacted in 1986 applies to permit the IRS to tax the U.S. affiliate on an additional 5% royalty.

The next example is the same, except the law where the foreign affiliate earns the extra income limits royalty payments to 5%. The foreign affiliate earns extra income by paying 5% rather than the 10% , FMV royalty. The 5% royalty rate is not commensurate with the income. The question in 3M is whether the IRS can apply the FMV commensurate with income royalty rate despite the local law prohibition?

In Commissioner v. First Sec. Bank of Utah, N.A., 405 U.S. 394 (1972), the Court held that pre-amendment § 482 did not permit an allocation where the recipient was not lawfully entitled to receive the income. In 3M, the taxpayer argued and the Eighth Circuit held that the commensurate with income standard did not apply because Brazilian law limited the royalty the 3M affiliate could pay 3M. The IRS argued that the 1986 commensurate with income amendment to § 482 permitted the allocation. I repeat the text of the commensurate with income standard: “ In the case of any transfer (or license) of intangible property (within the meaning of section 367(d)(4)), the income with respect to such transfer or license shall be commensurate with the income attributable to the intangible.” (Emphasis supplied.)

Loper Bright’s Motivated Mistreatment of Statutory Ambiguity and Best Interpretations (8/28/25)

On August 26, 2025, I gave a talk to a Houston tax group, the Wednesday Tax Forum. The paper I circulated was a high-level summary of a longer article that I have submitted for publication in the ABA Tax Lawyer in Spring 2024; the submitted article addresses the tax implications of Loper Bright Enterprises v. Raimondo, 603 U.S. 369, 377-378 (2024), see Preliminary Print here. I link that summary here so that readers may download if they wish. Note that the linked summary is redlined to show changes that I made shortly after giving the talk. I will not attempt to further summarize the arguments.

I address in this blog entry the overarching claim that I make. The domain of Chevron was a state of ambiguity where the court was not able to determine whether the agency interpretation or an opposing interpretation was the best interpretation. I call that state interpretive equipoise to relate it to the more familiar concept of factual equipoise where a factfinder is unable to determine whether a critical fact exists or not. In a state of factual equipoise, the factfinder resolves the issue by holding against the party bearing the burden of persuasion on that fact. In a state of interpretive equipoise, the court cannot find that either the agency interpretation or the opposing interpretation is the best interpretation. Chevron resolved the case in that state of interpretive equipoise, effectively placing on the opponent of the agency interpretation a burden to persuade the court that its opposing interpretation was “best.”

Why did Chevron tilt in favor of the agency interpretation in a state of interpretive equipoise? First consider the alternatives. Would it be acceptable for courts to decide in equipoise by flipping a coin, consulting a ouija board or soothsayer, or some other unprincipled way of resolving the ambiguity? Of course, that would not be acceptable. Still, courts must resolve interpretive issues in equipoise in some way. Chevron offered that way. I will address below why that is a principled resolution based on the APA, but I ask first what Loper Bright offered in lieu of Chevron to resolve cases of interpretive equipoise?

Loper Bright offers nothing for interpretive equipoise other than the ill-considered notion that courts can always interpret out all ambiguity to derive the single best interpretation. That would be nice if it made logical sense or experiential sense. Courts have the same interpretive skills after Loper Bright that they had under Chevron where they were admonished by Chevron’s famous footnote 9 to use those skills to avoid ambiguity where possible. Nevertheless, in some cases, ambiguity remained. I submit that cases of ambiguity—interpretive equipoise—will remain under Loper Bright. Loper Bright offers no guidance on what a court does where, using its best interpretive skills in de novo review, ambiguity exists.

Traditional Skidmore will not solve the problem of interpretive equipoise. Traditional Skidmore simply requires courts to respect agency interpretations in determining the best interpretations. The phenomenon I address here is where, after using all of those tools of interpretation (including Skidmore), the court cannot determine, as between the agency interpretation and the opposing interpretation, which is the best interpretation. Both interpretations must be in play—that is reasonable within the scope of the statutory ambiguity—but neither is the best interpretation. In that state of play, Loper Bright offers no way to resolve the case.

Of course, I say traditional Skidmore. Skidmore has traditionally been called Skidmore deference even though it was not deference but simply a consideration in reaching the best interpretation. See Really, Skidmore "Deference?" (Federal Tax Procedure Blog 5/31/20; 2/14/21), here. It is possible that, post-Loper Bright, courts may reimagine Skidmore to fill some of the conceptual space on the spectrum between respect and deference, sort of more than respect but less than deference, if that is a possible thing, say deference “light.” I can’t offer anything meaningful on that possibility.

Loper Bright’s Effects on the § 6751(b) Regulations (Herein Difference Between Regulations and Interpretations) (8/7/25)

I am today considering the wonders and discontinuities of Loper Bright Ent. v. Raimondo, 603 U.S. 369 (2024)(“Loper Bright”). I do this in the context of updating my Federal Tax Procedure Book editions. For this blog, I zero in on one facet related to Loper Bright’s perceived command that courts apply de novo the best statutory interpretation (whether or not it is the agency interpretation). The general rule is that judicial interpretations apply retroactively to the effective date of the statute. Harper v. Va. Dep't of Taxation, 509 U.S. 86 (1993). 

The context is the § 6751(b) regulations. 26 C.F.R. § 301.6751(b)-1, with an effective date of December 23, 2024. Those regulations were promulgated to resolve the inconsistent interpretations of § 6751(b) as courts flailed around, often inconsistently, to apply the textually nonsensical statute. Loper Bright denied Chevron deference from the fiction of statutory ambiguity, but said nothing about a statute that is ambiguous and textually nonsense. That requires that either (i) § 6751(b)  is facially invalid with no application or (ii) susceptible to interpretation which will require that lines be drawn similar to the way a line was drawn in United States v. Correll, 389 U.S. 299 (1967) (adopting the agency sleep and rest interpretive line for the statutory “away from home” requirement). In other words, a best interpretation could not be made until some authority draws the line.

At least in theory, in order to pass Loper Bright muster, the § 6751(b) interpretive regulations must state the best interpretation. For purposes of this discussion, I distinguish between the interpretation and the regulation which adopts the interpretation. The best interpretation should apply from the effective date of the statute. That means, for example, that the § 7805(b) limitations on retroactive effective dates for interpretive regulations may still apply to the regulation but are meaningless if the regulations state the best interpretation.

This phenomenon was always true but perhaps was not true for agency interpretations of ambiguous text that had no best interpretation from the effective date of the statute, but with a best interpretation discernible only by some action, such as a regulation interpretation, that permitted a best interpretation to be applied. E.g., United States v. Correll, 389 U.S. 299 (1967) (once the line drawing was approved in Correll, it applied to all pending and future cases).

Thus, the conundrum of effective dates for the § 6751(b) regulations is presented. If the interpretations in the § 6751(b) regulations are best interpretations, they apply from the effective date of the statute and should apply to pending Tax Court cases for periods prior to the regulations’ effective date of December 2024. If that is right, should not the courts in pending cases for periods prior to the December 2024 effective date be considering whether the regulations interpretation (not the regulation) applies. If the § 6751(b)  regulations are best interpretations for validity, why should courts for those pre-effective date periods not apply the best interpretations. In other words, why are Tax Court judges applying the mish-mash of interpretations preceding the effective date of the § 6751(b) regulations without considering the § 6751(b) interpretations? See e.g., Hancock County Land Acquisitions LLC v. Commissioner, T.C. Memo. 2025-50.