Accumulation of Permanent Disability Awards to Body Regions Under LC 4664(c)

When defendants seek to apportion an applicant's permanent disability, most often they look to apply Labor Code § 4663, which directs that apportionment be based on causation. LC 4663 requires a physician to consider factors both before and subsequent to the industrial injury, and the courts have not limited what can be apportioned under § 4663. They have allowed defendants to apportion to asymptomatic previous conditions, risk factors and even genetic factors. The only limitation has been that to apportion under § 4663, the physician's opinion about apportionment must be substantial evidence.

Labor Code § 4664 is the other statute that addresses apportionment in the California workers' compensation system, and it allows apportionment to a previous award of permanent disability benefits. LC 4664(b) states, "If the applicant has received a prior award of permanent disability, it shall be conclusively presumed that the prior permanent disability exists at the time of any subsequent industrial injury." If § 4664 applies, the percentage of permanent disability found under the previous award will be subtracted from the current overall percentage of disability.

To obtain apportionment under § 4664(b), a defendant has the burden of proving overlap between the previous and current disabilities. (Kopping v. WCAB (2006) 71 CCC 1229.) Because it is frequently difficult to prove overlap between a previous and a current disability, often the WCAB will deny apportionment under § 4664(b).

LC 4664(c)(1), however, contains a frequently overlooked apportionment scheme. It states that applicants may not accumulate, over one lifetime, permanent disability awards on a region of the body that exceed 100 percent. In subparagraphs A to G, it lists the regions of the body as:

1. hearing
2. vision
3. mental and behavioral disorders
4. spine
5. upper extremities, including the shoulders
6. lower extremities, including the hip joints
7. head, face, cardiovascular system, respiratory system and all other systems or regions of the body not listed in (A)-(F)

The only exception to this rule is if the applicant’s injury or illness is conclusively presumed to be total in character pursuant to LC 4662. If an applicant has an injury or illness that is conclusively presumed to result in permanent total disability, he or she could receive a 100 percent award. LC 4664(c)(2), however, directs that permanent disability for each individual injury may not exceed 100 percent.

Unlike § 4664(b), § 4664(c)(1) does require an employer to prove that the previous disability overlaps with the current disability. That is, § 4664(c)(1) can serve to reduce an applicant's award even if the current and previous disabilities do not overlap.

For example, in Russell v. County of Los Angeles, 2021 Cal. Wrk. Comp. P.D. LEXIS 152, the WCAB applied § 4664(c)(1) to reduce an employee's award from 100 percent to 66 percent. The applicant previously received an award of 83 percent permanent disability for orthopedic injuries and injuries to the upper digestive tract, a skin disorder, dietary restrictions, bruxism and temporomandibular joint disorder. He later claimed a cumulative trauma injury through February 2019 in the form of colon cancer, and was found to have 100 percent permanent disability. The WCAB held that application of the lifetime cap on the accumulation of more than 100 percent permanent disability for any one region of the body limited the applicant's recovery.

It found that his cumulative trauma claim for colon cancer fell within the catchall provision of § 4664(c)(1)(G). After rating the permanent disability from the previous award for the regions of the body that fell within the catchall provision at 34 percent permanent disability, the applicant was awarded only 66 percent permanent disability for the colon cancer claim. The WCAB explained that the issue of overlap between the previous and current permanent disability was not applicable when the 100 percent lifetime cap is reached. It also rejected the applicant's argument that § 4664(c)(1)(G) was inapplicable to awards based on rebuttal of a scheduled rating. So, even though the applicant's permanent total disability might have been caused entirely by the colon cancer, he could not receive a 100 percent award for the condition because it fell within the same body region for which he previously received an award.

Accordingly, to reduce their liability, defendants must consider whether § 4664(c) applies in high exposure cases. That the disabilities do not duplicate entirely or even partially will not preclude apportionment under that section. Per Russell, even if the previous award does not break down permanent disability by body region or system, the WCAB may rate the permanent disability of the body systems or regions in the earlier award and subtract that from the current disability if the applicant is 100 percent disabled.

Although defendants may not be able to use § 4664(c) frequently, when it can be applied, it could result in a significant reduction in a defendant's liability. For further discussion of apportionment under § 4664, see Sullivan on Comp Section 10.35 Apportionment –– Pre-Existing Disability.