Contributed by: Marina Tsikitas, Rule 19-220, Student Attorney in the Low Income Taxpayer Clinic
For tax professionals, the statutory notice of deficiency is a familiar but unforgiving document. Once the IRS mails a valid notice of deficiency, the taxpayer generally has 90 days (150 days if the notice is addressed to a person outside the United States) to petition the U.S. Tax Court.[1] If the petition arrives even one day late and no exception applies, the court will dismiss the case, and the taxpayer loses the chance to be heard.
During my work in the University of Baltimore Low-Income Taxpayer Clinic, I learned just how easy it is for that deadline to go wrong. One client received a notice of deficiency that clearly listed a response deadline of October 9th. When I counted 90 days from the notice date myself, I landed on October 6th. On paper, the IRS had given the taxpayer three extra days. That extra time would save them if they filed by October 9th, but the mismatch shows how fragile these timelines are, especially for people who do not have representation and may not file until it is already too late.
The “last day to petition” and what it really means
Congress knows that most people are not counting days on a calendar. In 1998, it amended I.R.C. § 6213(a) in the Internal Revenue Service Restructuring and Reform Act to require the IRS to print the “last day” to petition on each notice of deficiency and to treat any petition filed by that printed date as timely.[2] The idea was simple: taxpayers should be able to rely on the date on the notice instead of doing their own deadline math.
The IRS followed suit in its own guidance. The Internal Revenue Manual (I.R.M.) explains that an incorrect “last day to file petition with the U.S. Tax Court” does not invalidate the notice. Instead, Tax Court jurisdiction turns on the 90th (or 150th) day after the notice is mailed or, if later, the last day printed on the notice. [3]
In practice, that rule protects taxpayers when the IRS gives too much time. If the Code says the 90-day deadline falls on October 6th, but the notice says October 9th, a petition filed on October 9th is still timely. At the Clinic, we don’t assume the printed date is right. We always count forward 90 days from the mailing date and compare it to the “last day to petition” on the notice. When those dates do not match, we treat it as a red flag and talk with the client about filing as early as possible.
Is the 90-day deadline “jurisdictional”?
For years, the Tax Court and most courts of appeals treated the 90-day deadline as a strict jurisdictional rule. If the petition was late, the court said it had no power to hear the case, no matter how compelling the reason.[4]
In Hallmark Research Collective v. Commissioner, decided shortly after the Supreme Court’s decision in Boechler, the Tax Court held that § 6213(a)’s deadline is jurisdictional and not subject to equitable tolling.[5]
Things started to shift with Culp v. Commissioner. There, the Third Circuit held that the 90-day period in § 6213(a) is a claims-processing rule, not a jurisdictional bar, and that equitable tolling can apply.[6] Commentators and the National Taxpayer Advocate have noted that many Tax Court cases are dismissed each year as untimely, so Culp has the potential to open the courthouse doors for taxpayers who missed the deadline for reasons outside their control.[7]
Other courts of appeals and the Joint Committee on Taxation have recognized this trend. The Joint Committee’s description of H.R. 5349 notes that courts in several circuits now treat the deficiency deadline as non-jurisdictional and subject to equitable tolling.[8] Under the Golsen rule, the Tax Court follows those appellate decisions in cases that would be appealable to those circuits.[9]
What the Tax Court Improvement Act would change
The Tax Court Improvement Act (H.R. 5349) aims to make the rules consistent and fair. According to the Joint Committee on Taxation, the bill would explicitly allow the Tax Court to apply equitable tolling to the 90- day deadline in § 6213(a), no matter where the taxpayer lives or which circuit would hear the appeal.[10] It would also amend § 7459(d) so that if the court dismisses a case solely because equitable tolling does not apply, that dismissal would not count as a decision on the deficiency. The taxpayer could still choose to pay and pursue a refund in another court.[11]
A recent tax-policy update notes that on October 3rd, 2025, the House Ways and Means Committee unanimously reported H.R. 5349 out of committee. The same update explains that the bill would “amend Tax Code section 6213(a) to permit the Tax Court to apply equitable tolling in deficiency cases” and adjust § 7459(d) so taxpayers denied equitable tolling can still seek a refund in district court or the Court of Federal Claims.[12]
As of this writing, Congress has not enacted H.R. 5349. For most taxpayers, the 90-day rule still operates as a hard wall.
What taxpayers and practitioners should do right now
Until Congress changes the law, taxpayers and practitioners need to treat these deadlines as deadly serious.
- Recheck the date. Do not rely solely on the date printed on the notice. Independently count 90 (or 150) days from the notice date under § 6213(a). Calendar both dates. If they differ, treat the earlier one as the real danger point, even though the statute lets you rely on the later printed date.
- Educate clients and community members. Low-income and unrepresented taxpayers often assume that the government-printed date is both correct and flexible. The National Taxpayer Advocate has stressed that a timely petition is what gives the Tax Court jurisdiction in the first place and has urged Congress to clarify that equitable tolling applies in deficiency cases.[13]
In the end without any action from Congress, the lesson is simple: Always check the deadline yourself. Don’t rely solely on what’s printed on the notice. Because if that date is wrong the IRS doesn’t bear the cost – you do.
[1] I.R.C. § 6213(a)
[2] I.R.C. § 6213(a) (last sentence), as amended by Internal Revenue Service Restructuring and Reform Act of 1998, Pub. L. No. 105-206, § 3463, 112 Stat. 685, 764–65; H.R. REP. NO. 105-364, pt. 1, at 63 (1997); S. REP. NO. 105-174, at 90 (1998); STAFF OF J. COMM. ON TAXATION, 105TH CONG., GENERAL EXPLANATION OF TAX LEGISLATION ENACTED IN 1998, at 109–10 (Comm. Print 1998).
[3] I.R.S. INTERNAL REVENUE MANUAL § 4.8.9 (Jan. 10, 2023).
[4] See STAFF OF J. COMM. ON TAXATION, 119TH CONG., DESCRIPTION OF H.R. 5349, THE “TAX COURT IMPROVEMENT ACT” 8 (JCX-40-25) (2025).
[5] Hallmark Research Collective v. Commissioner, 159 T.C. 126 (2022)(holding that the 90-day deadline to file a deficiency petition under I.R.C. § 6213(a) is jurisdictional and not subject to equitable tolling, distinguishing Boechler; see Boechler, P.C. v. Commissioner, 596 U.S. 199 (2022) (holding that the 30-day deadline to file a CDP petition under I.R.C. § 6330(d)(1) is non-jurisdictional and subject to equitable tolling).
[6] Culp v. Commissioner, 75 F.4th 196 (3d Cir. 2023) (holding that § 6213(a)’s 90-day deadline is a non-jurisdictional claims-processing rule and is subject to equitable tolling, reversing the Tax Court’s dismissal).
[7] See Sonya C. Bishop & Marc Levey, Third Circuit Holds Tax Court’s 90-Day Petition Deadline Is Not Jurisdictional, Temple 10-Q (Apr. 10, 2024), https://www2.law.temple.edu/10q/third-circuit-holds-tax-courts-90-day-petition-deadline-is-not-jurisdictional; NAT’L TAXPAYER ADVOCATE, 2023 ANNUAL REPORT TO CONGRESS, supra note 7.
[8] JCX-40-25, supra note 8, at 8–9.
[9] Golsen v. Commissioner, 54 T.C. 742, 756–57 (1970), aff’d, 445 F.2d 985 (10th Cir. 1971) (adopting the rule that the Tax Court follows precedent of the court of appeals to which the case is appealable when that precedent is squarely on point).
[10] JCX-40-25, supra note 8, at 9–10.
[11] Id. at 10.
[12] Sullivan & Cromwell LLP, Tax Policy Update – November 17, 2025 (Nov. 17, 2025), https://www.sullcrom.com.
[13] NAT’L TAXPAYER ADVOCATE, Purple Book: Legislative Recommendations to Strengthen Taxpayer Rights 45–48 (2024).