Dehydration ICD-10-CM codes

Category E86 (volume depletion) has three billable codes: E86.0 dehydration, E86.1 hypovolemia, and E86.9 volume depletion unspecified. E86.0 is the code for nearly all documented dehydration. Hypovolemia (E86.1) is used when the provider documents intravascular volume loss without calling it dehydration. Volume depletion of the newborn is P74.1 and is not coded to E86.

Sequencing depends on the reason for the encounter. When the patient is admitted for dehydration and the treatment is directed at the dehydration alone, such as intravenous fluids for dehydration due to viral gastroenteritis, E86.0 is the principal diagnosis and the underlying condition (A08.4) is secondary. When the underlying condition is also treated, that condition is sequenced first. Dehydration integral to a condition, for example in diabetic ketoacidosis, is still reported if the provider documents it.

Related findings are coded in addition when documented by the provider: E87.0 hypernatremia, E87.1 hyponatremia, E87.20 acidosis unspecified (or E87.21 acute metabolic acidosis), R57.1 hypovolemic shock, and N17.9 acute kidney injury when the provider diagnoses AKI rather than only prerenal azotemia. Do not assign E86.0 from a BUN/creatinine ratio, a note of poor oral intake, or a nursing assessment; the diagnosis must appear in the provider documentation.