In apportionment under the AMA Guides, apportionment is based on?

In apportionment under the AMA Guides, apportionment is based on?

• A. Causation
• B. Medical report of treating physician
• C. Pre-existing disability
• D. Informal rating

Answer: (A)

Apportionment under the AMA Guides rests on causation—the question is what portion of a worker’s impairment is caused by the current work-related injury versus pre-existing or unrelated conditions. The amount allocated to the current injury reflects the causal contribution of that injury to the total impairment. The treating physician’s report may inform the impairment assessment, and a pre-existing disability can affect how the total impairment is divided, but the dividing principle is the causal connection between the injury and impairment. Informal rating isn’t a basis for apportionment, since it does not establish the necessary causal analysis. If the current injury accounts for all impairment, then no apportionment is needed; if part stems from a pre-existing condition, that portion is allocated accordingly.

Apportionment under the AMA Guides rests on causation—the question is what portion of a worker’s impairment is caused by the current work-related injury versus pre-existing or unrelated conditions. The amount allocated to the current injury reflects the causal contribution of that injury to the total impairment. The treating physician’s report may inform the impairment assessment, and a pre-existing disability can affect how the total impairment is divided, but the dividing principle is the causal connection between the injury and impairment. Informal rating isn’t a basis for apportionment, since it does not establish the necessary causal analysis. If the current injury accounts for all impairment, then no apportionment is needed; if part stems from a pre-existing condition, that portion is allocated accordingly.