What is the ICD-10 code for acute pyelonephritis?

The ICD-10-CM code for acute pyelonephritis is N10 when documented without further specification. More specific documentation changes the code — see the scenario table.

Yes — N10 is a billable ICD-10-CM code, but payers expect the most specific code the documentation supports.

ICD-10 Code for acute pyelonephritis

The ICD-10-CM code for acute pyelonephritis is N10 when documented without further specification. Acute pyelonephritis (acute infective tubulo-interstitial nephritis) codes to N10 - a single billable code with no subdivisions. When the culture identifies the organism, an additional code (B95-B97) reports the infectious agent.

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Symptom code vs. confirmed diagnosis

N10 is a confirmed diagnosis of acute pyelonephritis, not a symptom or lab code. It carries a use-additional-code note for the infectious agent (B95-B97) - report the organism whenever the culture documents it.

Which Code Should You Use?

N10 ✓ Billable — Acute pyelonephritis

Acute pyelonephritis (acute infective tubulo-interstitial nephritis).

What to Document

That the infection involves the kidney (pyelonephritis) rather than a lower urinary tract site, which is coded elsewhere.
The causative organism from culture, reported with an additional B95-B97 code per the use-additional note.
That the process is acute - chronic pyelonephritis is coded elsewhere.
Any associated obstruction, calculus, or reflux documented as a related condition.

Common Documentation Pitfalls

N10 is a complete code with no laterality or 6th character - do not seek a more specific N10 subcode.
Do not omit the additional B95-B97 organism code when the culture identifies the agent.

Instructional Notes for N10

Use Additional Code

code (B95-B97), to identify infectious agent.

Also Known As

Official ICD-10-CM Alphabetic Index terms that point to N10:

Nephrosis, nephrotic (Epstein's) (syndrome) (congenital) › myoglobin
Pyelonephritis › acute
Pyelitis (congenital) (uremic) › acute
Nephrosis, nephrotic (Epstein's) (syndrome) (congenital) › hemoglobin
Nephritis, nephritic (albuminuric) (azotemic) (congenital) (disseminated) (epithelial) (familial) (focal) (granulomatous) (hemorrhagic) (infantile) (nonsuppurative, excretory) (uremic) › tubulo-interstitial (in) › acute (infectious)

Coding Notes

The Alphabetic Index maps acute pyelonephritis to N10, a single billable code. Per its use-additional-code note, report the infectious agent (B95-B97) when the organism is documented. Acute pyelonephritis is distinct from chronic pyelonephritis, which is coded elsewhere.