Module 6 part 1

Question 1

Define “Apportionment” in workers’ compensation.

Answer 1

The process of determining what portion of an injured worker’s permanent disability (PD) is industrial (work-related) versus non-industrial (preexisting or subsequent non-work causes).

Question 2

Why is apportionment important?

Answer 2

It affects the % of PD benefits the employer/insurer must pay; ensures employers only pay for disability caused or aggravated by work.

Question 3

Legal basis for apportionment in CA WC?

Answer 3

Labor Code §4663 and §4664 — require physicians to parcel out PD between work-related and other causes.

Question 4

Key question in apportionment analysis?

Answer 4

“What % of this permanent disability was caused directly by the work injury versus other factors?”

Question 5

Industrial vs non-industrial factors examples.

Answer 5

Industrial: specific trauma, cumulative trauma, toxic exposure. Non-industrial: prior injury, degenerative disease, congenital condition, age-related changes.

Question 6

What is a “preexisting condition”?

Answer 6

A medical condition or impairment that existed before the current industrial injury and contributes to present disability.

Question 7

What is “pathology” in apportionment?

Answer 7

Objective structural change (e.g., degenerative disc disease) that may contribute to disability.

Question 8

What is “disability” for apportionment?

Answer 8

Functional loss or limitation affecting earning capacity or activities of daily living (ADLs).

Question 9

Difference between pathology & disability apportionment.

Answer 9

Pathology = structural abnormality; Disability = actual functional loss. Only disability apportionment reduces PD benefits.

Question 10

Mnemonic to remember apportionment analysis.

Answer 10

P.A.R.T. — Preexisting, Aggravation, Ratable impairment, Total %.

Question 11

Role of QME in apportionment.

Answer 11

Provide reasoned medical opinion allocating PD % to industrial and non-industrial causes based on evidence.

Question 12

What is “new injury” vs “aggravation” in apportionment?

Answer 12

New injury = fresh pathology from work; Aggravation = work worsens preexisting condition, may still apportion %.

Question 13

How to handle congenital conditions?

Answer 13

If asymptomatic before but now disabling after work trauma, still apportion if pathology contributed to PD.

Question 14

Substantial evidence for apportionment requires…

Answer 14

Clear reasoning, medical probability, discussion of records/history, and % allocation with explanation.

Question 15

Key documentation to review for apportionment.

Answer 15

Past medical records, imaging, prior WC claims, job description, current exam findings.

Question 16

Example: Preexisting 20% knee PD, work adds 10% PD.

Answer 16

Total PD = 30%; Apportion 20% non-industrial, 10% industrial.

Question 17

Effect of failing to discuss apportionment.

Answer 17

Report may be legally insufficient; claim may default to 100% industrial.

Question 18

Cumulative trauma apportionment challenge.

Answer 18

Difficult to separate preexisting vs repetitive work injury; requires detailed timeline & records.

Question 19

What is “overlap” in apportionment?

Answer 19

When prior and current injuries affect same body part/function — physician must estimate relative contribution.

Question 20

Labor Code §4664 effect.

Answer 20

If worker had prior PD award, that % is presumed non-industrial for current case (unless rebutted).

Question 21

Apportionment vs causation difference.

Answer 21

Causation = did work cause/aggravate injury; Apportionment = what % of PD is work-related vs other.

Question 22

Mnemonic for legal basis.

Answer 22

“2×4 Rule” — LC 4663 & 4664 govern apportionment.

Question 23

Why include non-industrial factors?

Answer 23

Ensures employer only liable for disability caused by work, not natural aging or unrelated disease.

Question 24

Pitfall: apportionment to age alone.

Answer 24

Not valid unless tied to demonstrable pathology/condition affecting function.

Question 25

How to apportion to prior surgery?

Answer 25

If prior surgery caused functional limits, can apportion % to non-industrial if evidence shows lasting PD.

Question 26

What is “apportionment to risk factors”?

Answer 26

Not valid — must be to actual pathology/disability, not mere risk (e.g., smoking history).

Question 27

QME checklist for apportionment opinion.

Answer 27

History, exam, diagnostics, identify non-industrial factors, % split with rationale.

Question 28

Why is clear apportionment reasoning critical?

Answer 28

WCAB may reject unsupported %, causing litigation or full industrial liability.

Question 29

When to state “no valid apportionment”?

Answer 29

If no credible non-industrial factors or evidence of preexisting PD/pathology.

Question 30

Example: Preexisting DJD 30% → work trauma adds 20%.

Answer 30

Report: 20% industrial, 30% preexisting DJD non-industrial.

Question 31

Mnemonic for steps.

Answer 31

H.E.A.R. — History, Evidence (records/imaging), Analyze contribution, Rate %.

Question 32

Difference between AMA impairment & apportionment.

Answer 32

AMA = degree of impairment; Apportionment = % of that impairment that is industrial.

Question 33

Consequences of over-apportioning.

Answer 33

Claim denial risk; WCAB can overturn if not supported by substantial medical evidence.

Question 34

Consequences of under-apportioning.

Answer 34

Employer overpays; report vulnerable to challenge by defense.

Question 35

How prior PD awards affect current case.

Answer 35

Prior % presumed non-industrial; can be rebutted with medical evidence of new worsening or distinct injury.

Question 36

Timing tip for apportionment.

Answer 36

Discuss at MMI (maximum medical improvement) when PD is stable and ratable.