“Fifty percent industrial, fifty percent non-industrial, based on the claimant’s degenerative disc disease.”
That sentence has ended more medical-legal reports than anyone would like to count, and it does not constitute substantial medical evidence.
Since Escobedo v. Marshalls, a valid apportionment opinion in California has to explain how and why the non-industrial factors are responsible for the percentage of permanent disability assigned to them. Not that they exist. Not that they are documented. How they caused the disability, and why the number is the number.
Judges reject reports over this constantly. What is worth noticing is that the rejection is rarely about the medicine.
The failure is usually documentary
Consider what a defensible apportionment opinion requires you to have in hand.
You need the pre-injury clinical picture, which means treatment records predating the industrial injury, sometimes by years. You need to know whether the degenerative findings were symptomatic before the injury, which means you need notes, not just imaging. You need the treatment history that followed, in order, so you can distinguish the trajectory attributable to the injury from the one the worker was already on. And you need to be able to point to specific documents when you write the reasoning.
Now consider the file you were sent. Seven hundred pages, unordered, in which the 2018 primary care notes sit between two copies of a 2023 MRI, and there is nothing at all from the two years before the injury because nobody requested it.
You can be entirely correct about the clinical picture and still be unable to write the paragraph the standard demands, because the paragraph requires evidence you do not have organised in front of you.
What a defensible paragraph contains
Work backwards from what survives cross-examination.
Name the non-industrial factor specifically. Degenerative disc disease at L4-5, not “degenerative changes.”
State when it was documented and by whom, with a date and a source. This is where an unordered file destroys you, because you cannot cite what you cannot find.
Explain the mechanism. Why does this condition produce this portion of the current disability, in this patient. A generic statement about degenerative conditions in the population is not an opinion about this worker.
Explain the number. If it is 40%, say what makes it 40 rather than 20. This is the part most reports skip entirely, and it is the part the standard is about.
Address what you did not have. If the pre-injury records are absent, say so, say what you would need, and say how that limits the opinion. A candid limitation survives; a confident number built on nothing does not.
Asymptomatic findings
One trap worth naming. Apportionment to an asymptomatic pre-existing condition has been repeatedly challenged, and reports that apportion to imaging findings alone, with no evidence of prior symptoms or disability, tend not to hold.
That distinction lives in the treatment notes rather than the radiology. Which brings you back to the file, and whether the notes are findable.
The cost of getting it wrong
A rejected apportionment finding does not just cost you a supplemental report. It costs the parties a case cycle, and it puts your name on a report that a judge declined to rely on.
The supplemental itself pays $650 under ML203 and includes 50 pages. If addressing the deficiency means re-reading a 700-page file, you are being paid $650 to do most of the work twice, and only if the issue was not already available to you the first time.
Where CUBEXLE fits
Our case-specific analysis for QME, AME and IME evaluators pulls the apportionment thread out of the file explicitly. Pre-injury treatment history separated and dated. Symptomatic versus asymptomatic documentation flagged. Gaps identified by name, so you know what is missing before you write rather than during a deposition.
You still write the opinion. We make sure the evidence for it is in front of you, in order, with page references you can cite. If a report of yours has been challenged on apportionment in the last year, send us the fact pattern. Write to connect@cubexle.com.