Major Contributing Cause

The compensability test

An employer must pay compensation if the employee suffers an accidental compensable injury arising out of work performed in the course and scope of employment. But the statute layers three requirements on top of that:

1. The injury, its occupational cause, and any resulting manifestations or disability must be established to a reasonable degree of medical certainty
2. That showing must be based on objective relevant medical findings
3. The accidental compensable injury must be the major contributing cause of any resulting injuries

Fail any one, and the claim fails, no matter how clearly the accident happened at work.

“Medical evidence only”

This sentence decides most disputes, and it is easy to miss.

Major contributing cause must be demonstrated by medical evidence only. Your testimony that you were fine before the accident and have been in pain ever since — however true, however credible — cannot establish major contributing cause. Neither can a supervisor’s account or a coworker’s.

Only a physician can say that the accident is more than 50 percent responsible. If no authorized doctor, IME, or expert medical advisor puts that opinion in the record, the claim lacks the evidence it needs, no matter how sympathetic the facts.

Preexisting conditions: “is and remains”

Where a work injury combines with a preexisting disease or condition to cause or prolong disability or the need for treatment, the employer pays only to the extent the work injury is and remains more than 50 percent responsible compared to all other causes combined, and thereafter remains the major contributing cause of the disability or need for treatment.

Read those words carefully, because they create something most injured workers do not expect: major contributing cause is a continuing requirement, not a one time hurdle.

A claim accepted as compensable in month one can be denied in month fourteen on the theory that the work injury is no longer the major contributing cause of the ongoing need for treatment — that the accident’s contribution has resolved and what remains is degenerative or unrelated. Carriers use this to end long running claims, and it is often the real basis for denying continued care.

Occupational disease and repetitive exposure

The bar is higher here. In cases involving occupational disease or repetitive exposure, both causation and sufficient exposure to support causation must be proven by clear and convincing evidence — a materially heavier standard than applies to a single traumatic accident.

This is why repetitive trauma claims — carpal tunnel, cumulative back injuries, toxic exposure — are harder to establish than a fall, and why they need medical evidence built deliberately from the start.

The safety rule reduction

Separately, § 440.09(5) provides that if an injury is caused by the employee’s knowing refusal to use a safety appliance or to observe a safety rule required by statute or lawfully adopted and brought to the employee’s knowledge before the accident, compensation is reduced 25 percent. This reduces benefits; it does not eliminate the claim.

Where MCC disputes go wrong

• No physician ever states the opinion. The single most common failure. Treating doctors document findings without ever addressing causation percentages.
• Degenerative imaging offered as the counterweight. Nearly every adult spine shows degeneration. Section 440.13(14)(a) provides that abnormal anatomical findings alone, absent objective relevant medical findings, are not an indicator of injury — which cuts against that argument.
• Late stage MCC denials. Care cut off months or years in on the theory that the accident is no longer the major contributing cause of the ongoing need for treatment.
• Repetitive trauma claims underbuilt. Clear and convincing evidence of both causation and sufficient exposure requires more than a diagnosis.
• Subjective complaints without objective findings. Real pain that imaging and examination do not corroborate is a genuine evidentiary problem under this statute.

What this means for your claim

Because only medical evidence can establish major contributing cause, the most valuable thing you can do is make sure your doctors have the full history. Tell every authorized physician exactly how the accident happened, what you could do before it, and what changed after. Causation opinions come from the medical record, and the medical record comes from what you report.

And if benefits are cut off well into a claim, look closely at whether the stated reason is a major contributing cause argument. That is a medical dispute, and medical disputes have mechanisms — an IME, an expert medical advisor, a petition for benefits.