§6501(e)(1)(a)(i)—I first heard of this section of the Internal Revenue Code in one of my initial classes at NYU in the program for an LL.M. in Tax (Masters in Tax Law). The professor who said it had no notes in front of him, no monitor, no nothing. I thought he was making some kind of obscure joke that I didn’t quite understand—surely no one could possibly be expected to memorize subsections of subsections of subsections of any particular section of the Internal Revenue Code. The fact is, I’ve never forgotten it.

At the time, §6501(e)(1)(A)(i) sounded more like a printer jam error than anything important: the rule that says if you omit more than 25% of the gross income reported on a return, the usual 3-year statute of limitations for the IRS to assess additional tax gets extended to 6 years. A sort of IRS “snooze button,” activated only when the taxpayer “forgets” to report a significant chunk of income.

Fast forward more than a decade later, and I’m in the thick of litigating a partnership case that was already giving me ulcers. The IRS had issued a Final Partnership Administrative Adjustment just shy of six years after the return was filed. Naturally, I raised the statute of limitations as a defense. Easy win, right?

Not so fast. According to the Service, the partnership had omitted over 25% of gross income—thanks to a tax basis overstatement that resulted in a massive reduction of gain. Which, they argued, counted as a “substantial omission” for §6501(e) purposes. That argument had legs… until the Supreme Court cut them off at the knees in United States v. Home Concrete & Supply, LLC, 566 U.S. 478 (2012).

In Home Concrete, the IRS had tried to do the exact same thing: turn a basis overstatement into an omission of income. But the Supreme Court disagreed, holding that an overstatement of basis—while it may affect the amount of income ultimately reported—doesn’t count as an “omission from gross income” under §6501(e). Score one for the home team.

Naturally, I thought this precedent meant I was in the clear. But again, not so fast. Unlike in Home Concrete, the taxpayer in my case hadn’t just overstated basis. They had actually failed to report a chunk of gross receipts from a disregarded entity held by the partnership. And the IRS had found it—buried deep in the attachments but nowhere near the face of the return.

Cue the next phase of the litigation: Was that omission adequately disclosed? Under Treas. Reg. §301.6501(e)-1, the six-year clock doesn’t apply if the taxpayer made an “adequate disclosure” of the omitted item in the return or in a statement attached to it. There’s an entire body of case law—some would say a small jungle—on what counts as “adequate.” Is the disclosure specific? Is it reasonably calculated to alert the IRS to the nature and amount of the omission? Does it require the IRS agent to perform minor math or major detective work?

I spent weeks arguing over the adequacy of the disclosure in the attachments. The IRS said the entry was too vague, buried in a schedule without explanation or context. I said the disclosure was clear enough for an agent to ask questions if they were paying attention—which, let’s face it, isn’t exactly a Constitutional standard, but it’s what I had.

In the end, the court sided with my argument, holding that the disclosure—while not textbook—was good enough to prevent the six-year statute from applying. The IRS was out of time. And there it was: the obscure, unpronounceable Code section from my first week at NYU had become the central pivot point in a real-world, high-stakes litigation.

So every once in a while, I think back to that professor, standing in front of the class quoting §6501(e)(1)(A)(i) from memory, no notes, no slides—just the Code and a kind of reverence for its power. Back then, I thought it was absurd that anyone could retain that level of detail. But now I realize: It wasn’t about memorization. It was about respect. Respect for the fact that in tax law, a single parenthetical in a forgotten subsection can quietly lie in wait for years—until one day, it decides the fate of millions of dollars, or the outcome of a case, or the difference between victory and defeat.

That’s the thing about the tax code. It’s not just a tangle of numbers and words. It’s a time bomb of consequences, and if you don’t know where the timers are hidden, you’ll never know which ones are about to go off. TWG knows, so you don’t have to. And yes, I remember §6501(e)(1)(A)(i). I always will. Not because I memorized it—but moreso because, to this day, I still wonder whether that professor was trying to teach tax law … or making a prophecy.