F71 — Moderate mental retardation

Concept, in one sentence

The same dual criteria as F70 (subnormal IQ plus matching adaptive-functioning deficit, developmental onset), at an approximate IQ range of 35-49 with typically more pervasive support needs.

Decisive boundary cues

• More pervasive daily-living support needs than F70's typical picture -> weighs toward F71.
• A milder, more circumscribed support-need picture -> weighs back toward F70.
• Support needs and IQ range consistent with the next threshold down -> weighs toward F72.

Duration/course cue

Onset during the developmental period, as a stable pattern.

Nearest alternatives

F70, F72

Common mistake

Assigning a grade from the IQ range alone without checking the breadth of the adaptive-functioning picture.

Retrieval prompt — one-line memory anchor

What would make you reconsider this as F70 instead of F71?