ICD-10-CM 2027
ICD-10 code for knee jerk abnormal
From the official ICD-10-CM alphabetic index entry “Abnormal, abnormality, abnormalities › knee jerk”. Page updated September 29, 2026.
About coding knee jerk abnormal
The ICD-10-CM code for knee jerk abnormal is R29.2 (Abnormal reflex).
Within R29 (other symptoms and signs involving the nervous and musculoskeletal systems), R29.2 is specifically for abnormal reflex. Related codes cover tetany (R29.0), Meningismus (R29.1), abnormal posture (R29.3), Clicking hip (R29.4), transient paralysis (R29.5), repeated falls (R29.6), National Institutes of Health Stroke Scale (NIHSS) score (R29.7), other symptoms and signs involving the nervous and musculoskeletal systems (R29.8) and 1 more.
The conditions in its Excludes2 note aren't part of R29.2, but may be coded alongside it if the patient has both: abnormal pupillary reflex (H57.0), hyperactive gag reflex (J39.2) and vasovagal reaction or syncope (R55).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
Common questions about knee jerk abnormal ICD-10 codes
What is the ICD-10 code for knee jerk abnormal?
- R29.2 — Abnormal reflex.
Is R29.2 billable?
- Yes. R29.2 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can R29.2 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict R29.2 as a principal diagnosis.
Is R29.2 a CC or MCC?
- No. R29.2 is neither a CC nor an MCC under MS-DRG v44.0.