Equitable tolling is a principle of law stating that a statute of limitations shall not bar a claim in cases where the plaintiff, despite use of due diligence, could not or did not discover the injury until after the expiration of the limitations period. Before 4/22/2015, when the United States was a defendant, equitable tolling could not be applied against the United States since the Spending Clause has been interpreted by the Supreme Court to only vest Congress with the authority to waive sovereign immunity, and statutes of limitation are interpreted as a condition on the waiver of sovereign immunity that limit the jurisdiction of a court to hear cases against the United States.
As of April 22, 2015, The Supreme Court of the United States, in US vs Wong ruled that equitable tolling CAN be applied against the United States, despite the Spending Clause. 
For example, when pursuing one of several legal remedies, the statute of limitations on the remedies not being pursued will be equitably tolled if the plaintiff can show:
- Timely notice to the adverse party is given within applicable statute of limitations of filing first claim
- Lack of prejudice to the defendant
- Reasonable good faith conduct on part of the plaintiff.
It has been held that equitable tolling applies principally if the plaintiff is actively misled by the defendant about the cause of action or is prevented in some extraordinary way from asserting his or her rights. However, it has also been held that the equitable tolling doctrine does not require wrongful conduct on the part of the defendant, such as fraud or misrepresentation.
In the United States
||This article contains too many or too-lengthy quotations for an encyclopedic entry. (April 2015)|
The United States Supreme Court elucidated:
Federal courts have typically extended equitable relief only sparingly. We have allowed equitable tolling in situations where the claimant has actively pursued his judicial remedies by filing a defective pleading during the statutory period, or where the complainant has been induced or tricked by his adversary's misconduct into allowing the filing deadline to pass. We have generally been much less forgiving in receiving late filings where the claimant failed to exercise due diligence in preserving his legal rights. ... But the principles of equitable tolling described above do not extend to what is at best a garden variety claim of excusable neglect.
The Supreme Court of Alaska distinguished the concepts of equitable tolling and equitable estoppel:
Federal precedent permits equitable estoppel or equitable circumstances to extend the three-year limitations period. Many federal cases seem to merge these two doctrines. For example, Seattle Audubon Society v. Robertson [931 F.2d 590 (9th Cir. 1991), rev'd on other grounds, 503 U.S. 429 (1992)] stated that equitable tolling may be applied when plaintiffs are “prevented from asserting their claims by some kind of wrongful conduct on the part of the defendant.” But it is only equitable estoppel that requires wrongful conduct on the part of the defendant, i.e., fraud or misrepresentation. The federal equitable tolling doctrine, on the other hand, does not require any conduct by the defendant.
Arizona courts have recognized and applied the equitable tolling doctrine. See Hosogai v. Kadota, 145 Ariz. 227, 229, 700 P.2d 1327, 1329 (1985) (applying doctrine when second wrongful death claim untimely filed after successful verdict on first claim overturned on appeal due to defective service of process); Kosman [v. State], 199 Ariz. 184, ¶¶ 6, 10, 16 P.3d at 213 (applying doctrine where plaintiff prisoner failed to timely file notice of claim against state because he first pursued claim through prison's administrative grievance procedure); Kyles v. Contractors/Eng'rs Supply, Inc., 190 Ariz. 403, 404, 406, 949 P.2d 63, 64, 66 (App.1997) (applying doctrine when right-to-sue letter from Arizona Attorney General's office contained incorrect date by which plaintiff was required to sue on his claim). See also McCloud v. State, Ariz. Dep't of Pub. Safety, 170 P.3d 691, 696 (Ariz. Ct. App. 2007).
The Supreme Court of California enunciated:
Equitable tolling is a judge-made doctrine which operates independently of the literal wording of the Code of Civil Procedure to suspend or extend a statute of limitations as necessary to ensure fundamental practicality and fairness. This court has applied equitable tolling in carefully considered situations to prevent the unjust technical forfeiture of causes of action, where the defendant would suffer no prejudice.
The Delaware Supreme Court examined the application of equitable tolling where defendants were subject to substituted service:
In any event, whatever the precise argument made may be, we think that the Delaware statute of limitations on actions for personal injuries runs continuously without interruption when there is available to the plaintiff throughout the period an acceptable means of bringing the defendant into court. Therefore, the answer to the first question posed is that there has been no tolling of the statute of limitations since these defendants, at all times, were subject to substituted service.
The Florida Supreme court observed, as an equitable remedy, the prejudice to the defendant must be considered before application:
The doctrine of equitable tolling was developed to permit under certain circumstances the filing of a lawsuit that otherwise would be barred by a limitations period. See Bailey v. Glover, 88 U.S. (21 Wall.) 342, 22 L.Ed. 636 (1874). The tolling doctrine is used in the interests of justice to accommodate both a defendant's right not to be called upon to defend a stale claim and a plaintiff's right to assert a meritorious claim when equitable circumstances have prevented a timely filing. Equitable tolling is a type of equitable modification which “‘focuses on the plaintiff's excusable ignorance of the limitations period and on [the] lack of prejudice to the defendant.'” Cocke v. Merrill Lynch & Co., 817 F.2d 1559, 1561 (11th Cir.1987) (quoting Naton v. Bank of California, 649 F.2d 691, 696 (9th Cir.1981)). Contrary to the analysis of the majority below, equitable tolling, unlike estoppel, does not require active deception or employer misconduct, but focuses rather on the employee with a reasonably prudent regard for his rights.
Maryland case law disfavors tolling the statute of limitations:
We have long maintained a rule of strict construction concerning the tolling of the statute of limitations. Absent legislative creation of an exception to the statute of limitations, we will not allow any implied and equitable exception to be engrafted upon it.
Arguably, appellees were on notice of Walko's claim once the motion to intervene was filed. As we have indicated, however, Walko's approach to this case was hardly one of vigilance. The statute of limitations reflects a legislative judgment of what is deemed an adequate period of time in which “a person of ordinary diligence” should bring his action. Ferrucci v. Jack, 255 Md. 523, 526, 258 A.2d 414 (1969); McMahan v. Dorchester Fert. Co., 184 Md. at 159, 40 A.2d 313. The unexplained delay in bringing a timely action here hardly bespeaks the “ordinary diligence” required of one seeking to toll the statute of limitations. Cromwell v. Ripley, 11 Md.App. at 182, 273 A.2d 218. In a very real sense, Walko has slept on its rights, Johnson v. Railway Express Agency, 421 U.S. 454, 466, 95 S.Ct. 1716, 44 L.Ed.2d 295 (1975), and cannot be heard to complain now for its own tarriance. See Braxton v. Virginia Folding Box Co., 72 F.R.D. at 126-27 (Before limitations had run, plaintiffs successfully intervened in pending civil rights action, but later voluntarily withdrew motion and commenced independent action seeking same relief after statutory period had expired; court held that limitations had not been tolled by timely and successful intervention, thus barring plaintiffs' independent action.).
The Court of Appeals of Michigan explicated that the plaintiff must exercise due diligence in order to invoke equitable tolling:
In view of the strong policy considerations favoring statutes of limitation, we hold that plaintiff's reliance upon a misdated court order did not constitute due diligence sufficient to toll the running of the statutory period of limitation. Defendant Pukoff should not be denied the protections afforded by the statute on so casual a basis. We hold that a minimum standard of due diligence in the case at bar would have included an investigation by plaintiff of the primary source of records of liquor licensees as of the date of the accident. A plaintiff's right to obtain information as to the identity of liquor licensees from the Michigan Liquor Control Commission is provided by the Michigan Freedom of Information Act. . . .
Mississippi courts require earnest efforts by plaintiffs seeking tolling:
The parties do not provide nor can we find any instance where “excusable neglect” has tolled or otherwise stayed a statute of limitations. That today's decision works to preclude McKinley's and Dixon's representatives' day in court is of no consequence. Watters v. Stripling, 675 So.2d 1242, 1244 (Miss.1996) (citing Traina v. United States, 911 F.2d 1155 (5th Cir. 1990)). There is nothing in the record to indicate that the representatives' failure to file was anything other than a result of their own inactions or omissions.
The Supreme Court of New Mexico opined:
Equitable tolling is a nonstatutory tolling theory which suspends a limitations period. See Gathman-Matotan Architects and Planners, Inc. v. State Dep't of Fin. & Admin., 109 N.M. 492, 494, 787 P.2d 411, 413 (1990). Equitable tolling typically applies in cases where a litigant was prevented from filing suit because of an extraordinary event beyond his or her control. Martinez v. Orr, 738 F.2d 1107, 1110 (10th Cir.1984). However, where a plaintiff fails to receive notice of the right to sue through his or her own fault, equitable tolling does not apply. See Baldwin County Welcome Ctr. v. Brown, 466 U.S. 147, 151, 104 S.Ct. 1723, 80 L.Ed.2d 196 (1984) (“One who fails to act diligently cannot invoke equitable principles to excuse that lack of diligence.”).
The North Dakota Supreme Court determined a plaintiff's failure to timely serve the defendants did not warrant equitable tolling:
Even if we were to adopt the equitable tolling doctrine in this case, Riemers' failure to commence his action against the defendants within the statute of limitations was not the result of his timely pursuit of one of several other available legal remedies which may have tolled the statute of limitations. Rather, as in Reid, 2000 ND 108, ¶ 16, 611 N.W.2d 187, Riemers' failure to commence his action within the statute of limitations resulted from his failure to effectuate timely service of process on the defendants. We therefore conclude the equitable tolling doctrine would not apply to Riemers' claims.
- 51 American Jurisprudence 2d Limitation of Actions § 174 (2007).
- Irwin v. Dep't of Veterans Affairs, 498 U.S. 89, 96 (1990) (footnotes and citations omitted).
- Abbott v. State, 979 P.2d 994, 997-998 (Alaska 1999) (footnotes omitted).
- Lantzy v. Centex Homes, 73 P.3d 517, 523 (Cal. 2003) (quotations and citations omitted).
- Hurwitch v. Adams, 155 A.2d 591,594 (Del. 1959).
- Machules v. Dep't of Admin., 523 So.2d 1132, 1133-1134 (Fla. 1988) (footnotes omitted).
- Hecht v. Resolution Trust Corp., 635 A.2d 394, 399 (Md. 1994) (quotations and citations omitted).
- Walko Corp. v. Burger Chef Sys., Inc., 378 A.2d 1100, 1104 (Md. 1977).
- Ray v. Taft, 336 N.W.2d 469, 473 (Mich. Ct. App. 1983).
- City of Tupelo v. Martin, 747 So.2d 822, 829 (Miss. 1999).
- Ocana v. American Furniture Co., 91 P.3d 58, 66 (N.M. 2004).
- Riemers v. Omdahl, 687 N.W.2d 445, 454 (N.D. 2004).