W53 vs W55
W53 (Contact with rodent) compared with W55 (Contact with other mammals), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. W55 carries an Excludes1 note covering W53: “bitten or struck by rodent (W53.-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| W53Contact with rodent | W55Contact with other mammals | |
|---|---|---|
| Billing status | Non-billable header Report instead: W53.01XA, W53.01XD, W53.01XS, W53.09XA, W53.09XD | Non-billable header Report instead: W55.01XA, W55.01XD, W55.01XS, W55.03XA, W55.03XD |
| Classification | V00-Y99 — External Causes of Morbidity (V00-Y99) | V00-Y99 — External Causes of Morbidity (V00-Y99) |
| Definition | Contact with rodent is a non-billable ICD-10-CM category code (W53). | Contact with other mammals is a non-billable ICD-10-CM category code (W55). |
| 7th character | The appropriate 7th character is to be added to each code from category W53 | The appropriate 7th character is to be added to each code from category W55 |
| Includes | contact with saliva, feces or urine of rodent | contact with saliva, feces or urine of mammal |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources