Apportionment — industrial versus other causes

What the Appeals Board did with this

Newest released decisions that turned on this issue. Each quotes the passage it turned on and links to the official PDF. Litigated tail — not a win rate, not a settlement value.

• ADJ17215880 · 2026-09-18 · Goleta District OfficeApportionmentapplicant prevailed

  Determinative passage · p.5Marshalls (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) The mere fact that a medical report assigns approximate percentages of industrial and nonindustrial causation does not make the report reliable medical evidence by itself. (E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Rather, the report must disclose familiarity with the concepts of apportionment, describe in detail the exact nature of the apportionable disability, and set forth the basis for the opinion that factors other than the industrial injury at issue caused permanent disability. (Escobedo, at p.

  The QME's apportionment opinion was found not to be substantial evidence because it relied on probability and mathematical division without adequate medical or factual support, and the parties stipulated to compensability of the left wrist injury as a specific injury, not cumulative. Defendant did not meet the burden of proof for apportionment.

  Official decision · page 5 →
• ADJ6958667 · 2026-09-11 · Van Nuys District OfficeApportionmentapplicant prevailed

  Determinative passage · p.8Given the inconsistent histories provided by the applicant, the court appropriately found that the apportionment opinions provided by Dr. Bertoldi and Dr. Sones were speculative and unsupported. Thus, Defendant did not meet its apportionment burden since the medical evidence Defendant relies upon is based on inconsistent applicant history that remains unresolved. Apportionment cannot be based on possibilities – it must be based on reasonable medical probability. Per Kopping, that is defendant's burden. [Kopping v. Workers' Comp. Appeals Bd. (2006) 142 Cal. App. 4th 1099, 1101.] Notwithstanding the foregoing, even though the reports of Dr. Bertoldi and Dr. Sones were not substantial on the issue of apportionment, the court still found them substantial with respect to findings on causation and impairment. In Republic Indemnity Co. of America v. WCAB (Winner) (2007) 72 CCC 1175, the WCJ properly relied on the valid portions of the medical reports even though neither physician's apportionment analysis was entirely convincing, demonstrating that a report may be unreliable on apportionment yet still substantial on other issues. Defendant failed to meet their burden of proof and as such the award was issued without apportionment.

  Defendant failed to meet burden of proving apportionment due to inconsistent applicant history and speculative medical opinions, so no apportionment was applied.

  Official decision · page 8 →
• ADJ14574913 · 2026-08-31 · Riverside District OfficeApportionmentdefendant prevailed

  Determinative passage · p.5defendant should be precluded from seeking a credit either partially, or in full, due to applicant’s allegation of employer negligence. Applicant argues on reconsideration that employer negligence was proven because the employer was aware of “Thirsty Thursdays” and failed to provide applicant a safe method of transport. (Petition for Reconsideration, p. 6, lines 25-28.) We agree with the WCJ that applicant has not established employer negligence solely based upon these allegations and thus, the employer is entitled to full credit. There is nothing in the record establishing that the male club member who was driving the car at the time of the accident was intoxicated. No police report is in evidence. Applicant did not testify that the driver had been drinking. According to applicant’s testimony the driver’s speed was the cause of the accident. It is unclear what connection “Thirsty Thursdays” has in this case as there is no evidence that intoxication was involved. Next, and even if we assume that the driver was intoxicated, applicant seeks to impart negligence upon the employer based upon the employer’s furnishing of alcohol to the driver. However, such civil liability is generally precluded under California law, and applicant argues no exception to the general exclusion. (Bus. & Prof., § 25602(b).) Accordingly, we deny reconsideration.

  Applicant failed to prove employer negligence; the employer was entitled to a credit for the civil recovery amount because the accident was caused by the speed of the driver, not intoxication or employer negligence.

  Official decision · page 5 →
• ADJ7529887 · 2026-07-29 · Van Nuys District OfficeApportionmentdefendant prevailed

  Determinative passage · p.2Based on the Report, and for the reasons discussed below, we affirm the December 28, 2022 Findings and Order. The Supreme Court in Ferguson held that the “previous disability or impairment” contemplated by section 4751 must be actually labor disabling. (Ferguson v. Industrial Acci. Com. (1958) 50 Cal.2d 469, 477; internal quotations omitted.) The court in Ferguson and Moyer v. Workmen’s Comp. Appeals (1972) 24 Cal.App.3d 650, 658 define labor disabling as impairment of earning capacity or diminished ability to compete in the open labor market. The issue here is whether a prior award of permanent disability automatically establishes that the disability is labor disabling. We agree with the WCJ that it does not.

  The Board agreed with the WCJ that a prior award of permanent disability does not automatically establish labor disabling status if the applicant was rehabilitated and no longer labor disabled at the time of the subsequent injury, supported by medical evidence and lack of objective evidence of impairment.

  Official decision · page 2 →
• ADJ11046834 · 2026-07-22 · San Diego District OfficeApportionmentdefendant prevailed

  Determinative passage · p.18Based on the opinion of primary treating physician Larry Dodge, M.D., applicant has 13 percent whole person impairment to her lumbar spine under the AMA Guides for the cumulative injury from November 3, 2003 through November 3, 2004. 8. Based on the opinion of qualified medical examiner Beth Bathgate, M.D., applicant’s cumulative injury from November 3, 2004 through September 11, 2017 caused whole person impairment of 13 percent under the AMA Guides. 9. Defendant has met its burden of establishing a total overlap between past and current injuries and thus has met it burden to show apportionment under section 4664(b). 10. Applicant has not suffered any additional permanent impairment or resulting permanent partial disability from the November 3, 2004 through September 11, 2017 industrial injury.

  Defendant met burden to show total overlap between prior and current injuries, supporting apportionment under Labor Code section 4664(b).

  Official decision · page 18 →
• ADJ19939689 · 2026-07-20 · Goleta District OfficeApportionmentapplicant prevailed

  Determinative passage · p.6Therefore, defendant carries the burden of proof on apportionment. (Lab. Code, § 5705.) Apportionment of permanent disability must address causation of disability and must constitute substantial evidence. (Escobedo, supra at pp. 611, 620-621.) To constitute substantial evidence “…a medical opinion must be framed in terms of reasonable medical probability, it must not be speculative, it must be based on pertinent facts and on an adequate examination and history, and it must set forth reasoning in support of its conclusions.” (Id. at 621.) Causation of disability is not to be confused with causation of injury. (Id. at 611.) Dr. Feingold’s apportionment opinions do not constitute substantial evidence because he does not address the causation of applicant’s disability, instead Dr. Feingold apportioned the applicant’s “impairment.” Evaluating physicians determine the extent of an applicant’s impairment using the AMA Guides, this is a medical determination. Then, the assigned impairment is rated or adjusted for the applicant’s diminished future earning capacity, occupation and age at the time of injury resulting in a level of permanent disability, this is a non-medical determination to account for an applicant’s inability to compete in the open labor market. (Lab.

  Dr. Feingold's apportionment opinions were rejected as substantial evidence because he apportioned impairment rather than disability, and failed to explain how non-industrial arthritis caused disability. The WCAB found no legal basis for apportionment.

  Official decision · page 6 →
• ADJ19727180 · 2026-07-20 · San Luis Obispo District OfficeApportionmentapplicant prevailed

  Determinative passage · p.6Apportionment is the process utilized to segregate permanent disability or the residuals caused by an industrial injury from those attributable to other industrial injuries or to nonindustrial factors, to allocate legal responsibility fairly. (Brodie v. Workers’ Comp. Appeals Bd. (2007) Cal.4th 1313, 1321 [72 Cal.Comp.Cases 565]; Marsh v. Workers’ Comp. Appeals Bd. (2005) 130 Cal.App.4th 906, 911 [70 Cal.Comp.Cases 787].) The mere fact that a medical report assigns approximate percentages of industrial and nonindustrial causation does not make the report reliable medical evidence by itself. (E.L. Yeager Construction v. Workers’ Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 927-928 [71 Cal.Comp.Cases 1687].) Instead, apportionment of permanent disability is “based on causation” and the “employer shall only be liable for the percentage of permanent disability directly caused by

  PQME Dr. Hyman provided substantial medical evidence that the applicant's permanent disability was entirely industrial, refusing to apportion any part to nonindustrial risk factors such as smoking, obesity, or genetic predisposition, which were only risk factors and not direct causes of the permanent disability. Defendant failed to meet the burden of proof to establish apportionment.

  Official decision · page 6 →
• ADJ11349173 · 2026-06-26 · Riverside District OfficeApportionmentdefendant prevailed

  Determinative passage · p.6Here, while the WCJ relied upon the submitted medical reporting from the AME/PQMEs for her findings on permanent disability, she found that the reports of Drs. Gupta and Wood are not substantial evidence on the issue of apportionment.

  The WCJ and WCAB found that the opinions of Drs. Gupta and Wood on apportionment lacked substantial medical evidence and reasoning, thus defendant did not meet its burden of proof on apportionment.

  Official decision · page 6 →