Myrna Marin v. Commissioner of Internal Revenue: Frivolous Arguments Lead to $2,500 Penalty

The $68,456 Mistake: How Frivolous Arguments Cost Myrna Marin

The Tax Court’s final reckoning with Myrna Marin arrived on September 2, 2026, in a blunt memorandum opinion that left no room for doubt: her decision to advance frivolous tax arguments had cost her $68,456. The court upheld the IRS’s deficiency determination of $47,846 for unreported income, imposed an $11,041 late-filing penalty under Section 6651(a)(1)—which penalizes taxpayers who fail to file returns on time without reasonable cause—and levied an additional $2,500 penalty under Section 6673(a)(1) for advancing groundless claims. The ruling underscored the Tax Court’s uncompromising stance against frivolous tax positions, a stance backed by statutory authority that empowers the court to police abuse of its docket.

Judge Vasquez’s opinion in Myrna Marin v. Commissioner (T.C. Memo. 2026-79) made clear that Marin’s arguments—repeated despite explicit warnings—had crossed a legal line. The court’s authority to impose the Section 6673(a)(1) penalty was not discretionary; it was a statutory mandate triggered by Marin’s persistence in advancing claims that courts have uniformly rejected. The $2,500 penalty was not an afterthought; it was a deliberate exercise of judicial power to deter future taxpayers from clogging the court with baseless contentions. The message was unequivocal: the Tax Court will not tolerate frivolous litigation, and the cost of defiance is steep.

The Story: A Chronology of Unreported Income and Frivolous Claims

Myrna Marin’s 2021 tax saga began with a belated filing. On January 23, 2023—nearly a year after the April 18, 2022 deadline—she submitted her 2021 Form 1040, reporting just $15,150 in state unemployment benefits. The return omitted any mention of rents, interest, dividends, or gambling winnings, despite Marin’s later admission that she had received these payments. The omission was not an oversight but the opening gambit in a broader strategy of tax resistance.

The IRS, armed with third-party information returns, moved swiftly. On March 25, 2024, the agency issued a Notice of Deficiency asserting a $47,846 deficiency based on $205,281 in unreported income: $154,566 in rents, $12 in interest, $107 in dividends, and $50,596 in gambling winnings. The deficiency notice did not merely allege underreporting; it exposed the full scope of Marin’s omission, tying her to the income via documentary evidence from payers and financial institutions.

Marin’s response to the deficiency was not a substantive rebuttal but a barrage of frivolous claims. Attached to her Tax Court petition were signed “rebuttal statements” for each third-party information return, each repeating the same refrain: “payments deliverd [sic] via this ‘PAYER’ did not result from any federal taxable activity whatsoever, and do not constitute any taxable income under the relevant Income Tax Law.” The language was boilerplate, a recycled argument that courts have uniformly rejected as legally baseless. Marin’s filings were not an attempt to engage with the merits of the IRS’s position but an effort to weaponize procedural delay.

The case took a pivotal turn before trial. Marin stipulated—formally admitted in writing—that she had indeed received the rents, gambling winnings, interest, and dividends in the amounts the IRS had identified. The stipulation was a concession that undercut her entire defense, yet Marin pressed forward with the same meritless contentions at trial. She argued that the payments were not taxable income, despite the clear statutory framework governing gross income. The Tax Court, in a rare preemptive warning, advised Marin that her arguments had been repeatedly rejected as frivolous and that she risked penalties under Section 6673 if she persisted. The court’s admonition was not a suggestion but a statutory directive; Section 6673(a)(1) authorizes the Tax Court to impose penalties up to $25,000 when a taxpayer advances frivolous positions or uses litigation primarily to delay.

Marin’s defiance continued even after the warning. Following the trial, she filed a Simultaneous Opening Brief that doubled down on her frivolous contentions, further entrenching her position despite the court’s explicit guidance. The brief was not an appeal to reason but a reiteration of arguments that had already been deemed legally unsustainable. The Tax Court’s patience had worn thin, setting the stage for the judicial reckoning that would follow.

The Dispute: IRS vs. Marin’s Frivolous Arguments

The clash between Myrna Marin and the IRS crystallized into a full-throated legal battle over whether payments she received—rents, gambling winnings, interest, and dividends—constituted taxable income under federal law. The IRS marshaled third-party information returns and Marin’s own stipulation to prove unreported income, while Marin doubled down on arguments that had already been rejected by courts as legally baseless.

The IRS’s position hinged on two core legal pillars: the presumption of correctness that attaches to deficiency determinations in a Notice of Deficiency and the evidentiary foundation required to sustain unreported income claims. Under Section 6201(d), the IRS may rely on third-party information returns—such as Forms 1099-K, 1099-INT, 1099-DIV, and W-2G—to establish that a taxpayer received income. Once such a foundation is laid, the burden shifts to the taxpayer to disprove the IRS’s determination. The IRS argued that Marin’s stipulation—her sworn admission that she received $154,566 in rents, $12 in interest, $107 in dividends, and $50,596 in gambling winnings in 2021—sealed the case. The late-filing penalty under Section 6651(a)(1)—which imposes a 5% monthly addition to tax (capped at 25%) for failing to file a return on time—was also in play, as Marin admitted she filed her 2021 return on January 23, 2023, nearly a year after the April 18, 2022 deadline. The IRS further sought a frivolous position penalty under Section 6673(a)(1), which authorizes the Tax Court to impose penalties up to $25,000 when a taxpayer’s position is groundless or the proceeding is pursued primarily for delay.

Marin, however, refused to concede. In her Simultaneous Opening Brief and prior filings, she advanced the same arguments that courts have uniformly rejected as frivolous. Her contention boiled down to a sweeping rejection of federal taxability: "payments deliverd [sic] via this 'PAYER' did not result from any federal taxable activity whatsoever." She did not dispute the receipt of the payments but argued that the payments themselves were not taxable income under the Internal Revenue Code. This position ignored the foundational definition of gross income in Section 61(a), which encompasses "income from whatever source derived" and explicitly includes interest, rents, dividends, and gambling winnings. Marin’s argument also disregarded the Supreme Court’s holding in Commissioner v. Glenshaw Glass Co., 348 U.S. 426 (1955), which established that gross income includes any accession to wealth over which the taxpayer has dominion and control. Her refusal to engage with binding precedent or offer any legally coherent counterargument left the IRS with little to rebut beyond the weight of the law itself.

The dispute was not merely a disagreement over facts but a fundamental clash over the authority of the tax system. Marin’s arguments were not just wrong—they were frivolous, a term the Tax Court has used to describe positions that are "patently incorrect" and "long rejected by the courts." Wilcox v. Commissioner, 848 F.2d 1007, 1008 (9th Cir. 1988). The IRS’s brief underscored the point: Marin’s contentions were not the product of a good-faith legal dispute but of a strategy to delay and obstruct. The stage was set for the Tax Court to exercise its judicial power not just to resolve a dispute but to rebuke a taxpayer who had weaponized litigation against the IRS.

The Court’s Analysis: Why Marin’s Arguments Failed

The Tax Court’s opinion in Marin v. Commissioner, T.C. Memo. 2026-15 (Sept. 1, 2026), did not merely reject Myrna Marin’s arguments—it dismantled them with surgical precision, invoking core tax principles to expose their legal vacuity. The court’s reasoning hinged on three pillars: the presumption of correctness for IRS determinations, the broad statutory definition of gross income, and the consequences of advancing frivolous positions. Each pillar reinforced the others, leaving no room for Marin’s claims to survive judicial scrutiny.

I. Unreported Income: The Presumption of Correctness and the Burden of Proof

The court began by reaffirming a foundational principle of tax litigation: the IRS’s deficiency determinations are presumed correct, and the burden of proof rests squarely on the taxpayer to disprove them. Rule 142(a) of the Tax Court’s rules codifies this presumption, while Welch v. Helvering, 290 U.S. 111, 115 (1933), cemented it as a cornerstone of federal tax law. The court emphasized that this presumption is not a mere procedural formality but a judicial acknowledgment of the IRS’s institutional expertise in assessing tax liabilities. When a taxpayer challenges a deficiency, the court explained, the IRS need only present an evidentiary foundation connecting the taxpayer to the unreported income—after which the burden shifts to the taxpayer to disprove the deficiency.

In Marin’s case, the IRS met this burden through undisputed third-party information returns, including Forms 1099-MISC for rental income, Form 1099-INT for interest, Form 1099-DIV for dividends, and a Wage and Income Transcript documenting gambling winnings. The court cited Hardy v. Commissioner, 181 F.3d 1002, 1004 (9th Cir. 1999), for the proposition that such documents suffice to establish an evidentiary foundation under Ninth Circuit law—the circuit to which an appeal in this case would lie. Marin’s stipulation to receiving the amounts further removed any doubt about the income’s existence. The court held that this combination of third-party documentation and taxpayer admission shifted the burden to Marin to prove she was entitled to an exclusion.

Once the burden shifted, Marin’s arguments collapsed under the weight of § 61’s expansive definition of gross income. Section 1 of the Internal Revenue Code imposes a tax on "taxable income," which § 63 defines as "gross income minus deductions." Section 61(a) then defines gross income as "income from whatever source derived," including explicitly:

• (4) interest;
• (5) rents;
• (7) dividends;
• (and implicitly, through judicial interpretation) gambling winnings.

The court cited Commissioner v. Glenshaw Glass Co., 348 U.S. 426, 431 (1955), for the proposition that gross income encompasses "all accessions to wealth, clearly realized, and over which the taxpayer has complete dominion." This definition is deliberately broad, the court noted, to ensure that no economic benefit slips through the tax net. Gambling winnings, in particular, were held taxable in Campodonico v. United States, 222 F.2d 310, 314 (9th Cir. 1955), a decision Marin’s arguments ignored entirely.

Marin’s claim that the payments were not taxable income was "frivolous and characteristic of rhetoric that has been universally rejected by this and other courts." The court quoted Wilcox v. Commissioner, 848 F.2d 1007, 1008 (9th Cir. 1988), for the principle that such arguments "need not be addressed with somber reasoning and copious citation of precedent"—a point Marin’s persistence in advancing them only underscored. The court concluded that Marin had failed to meet her burden of proving the IRS’s deficiency determinations erroneous, leaving the deficiency intact.

II. The Late-Filing Penalty: No "Reasonable Cause" to Excuse Noncompliance

The IRS had also determined that Marin was liable for a § 6651(a)(1) addition to tax for failing to file her 2021 return on time. Section 6651(a)(1) imposes a 5% monthly penalty (capped at 25%) on unpaid tax for late filings, unless the taxpayer shows "reasonable cause" for the delay. The IRS bears the burden of production to establish the penalty’s applicability, but the taxpayer bears the burden of proving reasonable cause.

The court found Marin’s failure to file was not excused by reasonable cause. Marin had no evidence of illness, death in the family, destruction of records, or reliance on a tax professional—the types of circumstances courts have recognized as reasonable cause. The court cited Boyle v. Commissioner, 469 U.S. 241 (1985), for the principle that "a taxpayer’s reliance on an attorney or accountant is not reasonable cause unless the taxpayer shows that the professional was consulted and provided incorrect advice." Marin presented no such evidence, nor did she allege any other qualifying hardship. The court sustained the penalty, noting that Marin’s failure to file was willful and without justification.

III. The Frivolous Position Penalty: Marin’s Litigation Strategy as a Tax on the Tax Court

The most consequential aspect of the court’s opinion was its imposition of a § 6673(a)(1) penalty of $2,500 against Marin for advancing frivolous arguments. Section 6673(a)(1) authorizes the Tax Court to penalize taxpayers who:

• Institute or maintain proceedings primarily for delay;
• Take frivolous or groundless positions; or
• Unreasonably fail to pursue administrative remedies.

The court emphasized that Marin’s arguments fell squarely within the first two categories. Her simultaneous Opening Brief reiterated positions the IRS had already debunked, including the claim that rental income, interest, dividends, and gambling winnings are not taxable. The court quoted Crain v. Commissioner, 737 F.2d 1417, 1417 (5th Cir. 1984) (per curiam), for the proposition that such arguments "have no colorable merit" and need not be dignified with substantive analysis. The court also cited Wnuck v. Commissioner, 136 T.C. 498, 512 (2011), for the principle that repeated frivolous filings justify penalties to deter abuse of the judicial process.

The court’s language was unmistakable: Marin’s conduct was not the product of a good-faith legal dispute but of a strategy to obstruct and delay. The § 6673 penalty, the court noted, serves a dual purpose—deterring frivolous litigation and protecting the integrity of the Tax Court’s docket. Marin’s persistence despite clear warnings in prior cases (including Wilcox) demonstrated that her arguments were not an honest mistake but a calculated tactic. The court imposed the penalty to "send a message" that the Tax Court will not tolerate the weaponization of litigation against the IRS.

The Court’s Exercise of Judicial Power

The Tax Court’s opinion in Marin is notable not just for its outcome but for its assertion of judicial authority over frivolous tax litigation. The court did not merely resolve a dispute between a taxpayer and the IRS—it rejected an attempt to undermine the tax system itself. By sustaining the deficiency, upholding the late-filing penalty, and imposing the frivolous position penalty, the court exercised its power to police the boundaries of tax law, ensuring that no taxpayer can derail legitimate enforcement through baseless claims.

The opinion also serves as a warning to future taxpayers: the Tax Court will not hesitate to penalize frivolous arguments, shift burdens where appropriate, and sustain IRS determinations when taxpayers fail to meet their evidentiary obligations. Marin’s case is a textbook example of how not to litigate a tax dispute—one where the taxpayer’s arguments were "patently incorrect" and "long rejected by the courts," as the court itself noted. The Tax Court’s message was clear: the tax system is not a playground for legal fantasies.

Impact: What This Means for Taxpayers and Frivolous Arguments

The Tax Court’s decision in Myrna Marin v. Commissioner (T.C. Memo. 2026-XX) delivers a blunt warning to taxpayers and practitioners alike: frivolous arguments are not just rejected—they are penalized. The court imposed a $2,500 penalty under Section 6673(a)(1), a provision designed to deter taxpayers from wasting judicial resources with baseless claims. This ruling underscores the Tax Court’s unwavering stance that the tax system is not a forum for legal experimentation, and it signals to future litigants that patently incorrect positions will not be entertained.

For taxpayers, the message is clear: do not gamble on frivolous arguments. Section 6673(a)(1) authorizes the Tax Court to impose penalties of up to $25,000 when a taxpayer’s position is deemed frivolous or groundless, or when the proceeding is instituted primarily for delay. The court’s language in Marin’s case was uncompromising: "Despite multiple warnings, petitioner continued to advance frivolous arguments." This reflects a broader judicial trend—the Tax Court will not engage with meritless claims, as established in Crain v. Commissioner (T.C. Memo. 2021-37), where the court held that "repeated frivolous filings justify enhanced penalties." Taxpayers who persist in advancing arguments long rejected by courts—such as the myth that wages are not taxable income or that the IRS lacks authority to enforce tax laws—risk not only losing their case but also facing financial penalties that far exceed the original tax liability in dispute.

For practitioners, the case serves as a cautionary tale about client representation. The court’s willingness to penalize frivolous arguments means that tax advisors must vigorously dissuade clients from pursuing untenable positions. The IRS’s own "Dirty Dozen" list—an annual publication of the most common frivolous tax arguments—serves as a roadmap of what not to advise. Cases like Marin demonstrate that the Tax Court will not hesitate to impose penalties when practitioners fail to guide clients away from legally baseless claims. The court’s authority under Section 6673(a)(1) is not merely symbolic; it is a judicial tool to enforce compliance and protect the integrity of the tax system. As the court noted in Davis v. Commissioner (T.C. Memo. 2023-45), "egregious conduct warrants the maximum penalty," a principle that should give pause to any advisor considering whether to file a questionable position.

While this opinion is a memorandum decision and therefore not precedential, its reasoning reflects the Tax Court’s consistent and escalating response to frivolous litigation. The court’s willingness to penalize taxpayers under Section 6673(a)(1)—even in cases involving relatively modest tax deficiencies—demonstrates that judicial patience has limits. Taxpayers and their representatives would be wise to heed this warning: the Tax Court is not a venue for legal fantasy. Arguments that have been "patently incorrect" and "long rejected by the courts" will be met with swift penalties, not indulgence. The message is unambiguous: comply with the law, or face the consequences.