Unspecified Neurocognitive Disorder 643
This category is included to cover the clinical presentation of a neurocognitive disorder (NCD)
for which there is evidence that multiple medical conditions have played a probable role in the
development of the NCD. In addition to evidence indicative of the presence of multiple med-
ical conditions that are known to cause NCD (i .e., findings from the hi story and physical ex-
amination, and laboratory findings), it may be he lpful to refer to the diag nostic criteria and text
for the various medical etiologies (e.g., NCD du e to Parkinson’s disease) for more information
on establishing the etiological connection  for that particular medical condition.
Unspecified Neurocognitive Disorder
799.59 (R41.9)
This category applies to presentations in which symptoms characteristic of a neurocogni-
tive disorder that cause clinically significant distress or impairment in social, occupational,
or other important areas of functioning predominate but do not meet the full criteria for any
of the disorders in the neurocognitive diso rders diagnostic class. The unspecified neuro-
cognitive disorder category is used in situations in which the precise etiology cannot be
determined with sufficient certainty to make an etiological attribution.
Coding note:  For unspecified major or mild neurocognitive disorder, code 799.59 (R41.9).
(Note:  Do not use additional codes for any presumed etiological medical conditions. Be-
havioral disturbance cannot be coded but may be indicated in writing.)