F72 — Severe mental retardation

Concept, in one sentence

The same dual criteria as F70/F71, at an approximate IQ range of 20-34, with typically extensive, lifelong support needs.

Decisive boundary cues

• A confidently completed assessment at this range -> weighs toward F72.
• An assessment confounded by an associated sensory/physical impairment -> weighs toward F78 instead.
• Support needs and range consistent with the profound threshold -> weighs toward F73.

Duration/course cue

Onset during the developmental period, as a stable, typically lifelong pattern.

Nearest alternatives

F71, F73, F78

Common mistake

Assuming a severe grade whenever an associated physical or sensory impairment is present, rather than checking whether assessment was actually achievable.

Retrieval prompt — one-line memory anchor

What would tell you that grading here was actually confounded, pointing toward F78 instead?