How long, and from what
- 1 yearStart proceedings at the WCABfrom date of injury / last day covered by disability payments / last day medical treatment was provided · Lab. Code § 5405
Lab. Code § 5412: the date of injury is the day the worker first suffered disability and knew, or should have known, that work caused it. Then Lab. Code § 5405: one year from the latest of that date, the last disability payment and the last treatment.
Enter both dates.
What the statute says
Lab. Code § 5405
“is one year from any of the following: (a) The date of injury. (b) The expiration of any period covered by payment under Article 3 (commencing with Section 4650) of Chapter 2 of Part 2. (c) The last date on which any benefits provided for in Article 2 (commencing with Section 4600) of Chapter 2 of Part 2 were furnished.”
Lab. Code § 5412
“is that date upon which the employee first suffered disability therefrom and either knew, or in the exercise of reasonable diligence should have known, that such disability was caused by his present or prior employment”
Full text of Labor Code § 5412
The date of injury in cases of occupational diseases or cumulative injuries is that date upon which the employee first suffered disability therefrom and either knew, or in the exercise of reasonable diligence should have known, that such disability was caused by his present or prior employment.
§ 5412 on SimilarCase →Official text · leginfo.legislature.ca.gov →
Full text of Labor Code § 5405
The period within which proceedings may be commenced for the collection of the benefits provided by Article 2 (commencing with Section 4600) or Article 3 (commencing with Section 4650), or both, of Chapter 2 of Part 2 is one year from any of the following: (a) The date of injury. (b) The expiration of any period covered by payment under Article 3 (commencing with Section 4650) of Chapter 2 of Part 2. (c) The last date on which any benefits provided for in Article 2 (commencing with Section 4600) of Chapter 2 of Part 2 were furnished.
§ 5405 on SimilarCase →Official text · leginfo.legislature.ca.gov →
How the days are counted
8 CCR § 10600(a)
“is computed by excluding the first day and including the last”
8 CCR § 10600(b)
“the act or response may be performed or exercised upon the next business day”
A last day on a weekend or WCAB holiday moves to the next business day where the rule allows it; elsewhere the calculator keeps the day and says it is closed.
When it passes — and when it moves
The date of injury moves every clock that runs from it: the § 5405 year, the § 5410 five years, and which year’s benefit rates apply.
Both dates are findings of fact. Panels read “disability” as compensable temporary or permanent disability, not treatment alone, and “should have known” is often tied to a doctor telling the worker the condition is work-related. The calculator orders the two dates you give; it does not decide either of them.
What the Appeals Board said about this deadline
Newest released decisions whose stated standard names § 5412 or § 5405, each with the passage it turned on and the official PDF. Litigated tail, not a count of how often the deadline is missed.
- ADJ10656647 · 2026-09-14 · San Francisco District Office§ 5412
Determinative passage · p.7Cal.Comp.Cases 722]; Alford v. Industrial Accident Com. (1946) 28 Cal.2d 198 [11 Cal.Comp.Cases 127].) Where permanent disability results from cumulative trauma, the injury occurs not at the time of exposure, but at the time the cumulative effect of the injury resulting from the exposure has ripened into disability. (See Federal Insurance Co. v. Workers' Comp. Appeals Bd. 221 Cal.App.4th 1116 [78 Cal.Comp.Cases 1257].) As used in section 5412, "disability" means either compensable temporary disability or permanent disability. (Chavira v. Workers' Comp. Appeals Bd. (1991) 235 Cal.App.3d 463 [56 Cal. Comp. Cases 631]; State Comp. Ins. Fund v. Workers' Comp. Appeals Bd. (Rodarte) (2004) 119 Cal.App.4th 998 [69 Cal. Comp. Cases 579].) Medical treatment alone is not "disability" for purposes of determining the date of a cumulative injury pursuant to Labor Code section 5412, but it may be evidence of compensable permanent disability. (Rodarte, supra, 119 Cal.App.4th at p. 1005.) In this case, the parties framed the issue of the section 5412 date of injury for trial but the F&O includes no finding thereon. (Minutes of Hearing, August 3, 2022, p.
Applied to determine the date of injury for the cumulative trauma claim.
Official decision · page 7 → - ADJ17096552 · 2026-09-04 · San Diego District Office§ 5412
Determinative passage · p.5B. Knowledge of Industrial Injury As noted above, Labor Code section 5500.5(a) sets the liability date as the earlier of the one-year period preceding the last date of injurious exposure and the Labor Code section 5412 date of injury. Section 5412 defines the date of injury in cumulative injury cases as “that date upon which the employee first suffered disability therefrom and either knew, or in the exercise of reasonable diligence should have known, that such disability was caused by his present or prior employment.” (Lab. Code, § 5412.) With regard to the date that an injured worker “knew, or in the exercise of reasonable diligence, should have known” that a disability was industrial, in City of Fresno v. Workers’ Comp. Appeals Bd. (Johnson) (1985) 163 Cal.App.3d 467, 472 [50 Cal.Comp.Cases 53], the Court of Appeal advised, “An employee clearly may be held to be aware that his or her disability was caused by the employment when so advised by a physician. Generally, until he receives such medical advice, he is not chargeable with knowledge of his condition and its relation to his work…” Zurich argues that applicant was chargeable with knowledge of the industrial nature of the injury because he knew that he worked in a dusty environment and that he was told in the hospital in August of 2022 that his condition “could have been caused” by his work.
Applied to determine the date of injury and knowledge of industrial causation.
Official decision · page 5 → - ADJ13553712 · 2026-08-10 · Fresno District Office§ 5412
Determinative passage · p.7The date of injury in cases of occupational diseases or cumulative injuries is that date upon which the employee first suffered disability therefrom and either knew, or in the exercise of reasonable diligence should have known, that such disability was caused by his present or prior employment.
The Board applied this standard to determine that the issue of the date of injury was not established as of March 6, 2020, due to lack of knowledge of work-related causation.
Official decision · page 7 → - ADJ20958335 · 2026-08-03 · San Bernardino District Office§ 5412
Determinative passage · p.4In this case, applicant was not provided with workers’ compensation benefits so the relevant point for statute of limitations purposes is the date of injury. The date of injury in cumulative injury cases is “that date upon which the employee first suffered disability therefrom and either knew, or in the exercise of reasonable diligence should have known, that such disability was caused by his present or prior employment.” (Lab. Code, § 5412.) “A ‘disability’ under the Workmen’s Compensation Law connotes an inability to work.” (Herrera v. Workmen’s Comp. Appeals Bd. (1969) 71 Cal.2d 254, 257 [34 Cal.Comp.Cases 382].) In State Compensation Ins. Fund v. Workers’ Comp. Appeals Bd. (Rodarte) (2004) 119 Cal.App.4th 998 [69 Cal.Comp.Cases 579], the Court of Appeal made clear that neither medical treatment nor modified work restrictions without wage loss, in and of themselves, are sufficient to constitute “disability” for purposes of Labor Code section 5412. As explained in Rodarte, Labor Code section 5412 requires compensable disability, either temporary or permanent. Permanent disability is not compensable until it is ratable. Except in the case of insidious, progressive
The WCAB ordered further development to clarify when applicant first suffered compensable disability for statute of limitations purposes.
Official decision · page 4 → - ADJ13520237 · 2026-07-28 · Los Angeles District Office§ 5412
Determinative passage · p.164. The date of cumulative injury pursuant to Labor Code section 5412 is September 1, 2020.
Date of injury is September 1, 2020, based on first temporary disability and knowledge.
Official decision · page 16 → - ADJ10326531 · 2026-07-21 · Anaheim District Office§ 5405
Determinative passage · p.38 [50 Cal.Comp.Cases 411].) The burden is on defendant to show when the statute of limitations began to run, “starting from any and all three points designated [in Labor Code section 5405].” (Colonial Ins. Co. v. Industrial Acc. Com. (Nickles) (1945) 27 Cal.2d 437, 441 [10 Cal.Comp.Cases 321].) The three points designated in section 5405 are date of injury (Lab. Code, § 5405, subd. (a)); the last payment of disability indemnity (Lab. Code, § 5405, subd. (b)); and the last date on which medical treatment benefits were furnished (Lab. Code, § 5405, subd.
The claim was timely filed within one year of the date of injury as no medical or disability benefits were provided.
Official decision · page 3 → - ADJ8450336 · 2026-07-15 · Salinas District Office§ 5412
Determinative passage · p.11not rebut the section 3212.2 presumption of compensability for either the July 20, 2010 specific injury or the cumulative trauma period from March 5, 2007, to January 11, 2013. Because we find industrial causation, we must determine the date of injury pursuant to section 5412. The record establishes that no physician informed applicant that her hypertension related to her employment or provided her any work restrictions. Applicant first acquired knowledge of the industrial nature of her cardiac condition upon the issuance of PQME Dr. Mahmoudi’s March 9, 2018 supplemental report. In that report, PQME Dr. Mahmoudi identified the LVH and concluded it reasonably occurred during the course of her employment. Therefore, we concur with applicant’s contention and find the date of injury pursuant to section 5412 is March 9, 2018.
Date of injury set as March 9, 2018 based on PQME Dr. Mahmoudi's report.
Official decision · page 11 → - ADJ3719477 · 2026-06-15 · Bakersfield District Office§ 5412
Determinative passage · p.10IV. We next address defendant's contention that in ADJ10346752, the WCJ did not decide whether the Petition to Reopen filed on January 9, 2020 was timely. (Petition, at p. 6.) The WCJ found that "[t]he undated Petition to Reopen was filed on January 9, 2020." (Findings of Fact No. 1.) Defendant argues that the parties stipulated and the WCAB approved the Stipulations with Request for Award for a date of injury of March 28, 1986 to January 16, 2012. (Petition, at p. 6.) As the Petition was filed more than five years from the end date of the cumulative trauma injury, January 16, 2012, defendant argues it is untimely. (Id.) Workers' compensation pleadings may be amended by the Appeals Board to conform to proof, based on evidence submitted at trial. (Cal. Code Regs., tit. 8, § 10517; Rubio v. Workers' Comp. Appeals Bd. (1985) 165 Cal.App.3d 196, 199-200 [50 Cal.Comp.Cases 160].) The parties' stipulations are not binding on the Appeals Board or the WCJ and the Appeals Board or the WCJ may reject or amend a stipulation and base the decision on the evidence presented at the hearing. (Lab. Code, § 5702; Cal. Code Regs., tit. 8, § 10517; Rubio, supra; Draper v. Workers' Comp. Appeals Bd. (1983) 147 Cal.App.3d 502 [48 Cal.Comp.Cases 748]; Turner Gas Co. v.
The WCAB found the date of injury for the cumulative trauma in ADJ10346752 to be October 17, 2016, based on medical evidence, making the Petition to Reopen timely.
Official decision · page 10 →
All 133 decisions on § 5412 →All 55 decisions on § 5405 →
Forms and where to file
Official forms reprinted from DWC, by number
Also on this
Questions about this deadline
What is the date of injury for cumulative trauma in California?
The date the employee first suffered disability from the cumulative injury and either knew, or with reasonable diligence should have known, that it was caused by work (§ 5412). It is the later of the two, because both have to be true.
Does medical treatment start the cumulative trauma clock?
Panels read “disability” in § 5412 as compensable temporary disability or permanent disability, not medical treatment alone. When disability began is decided on the evidence; the decisions below show how.