N41.9Inflammatory disease of prostate, unspecified

N41.9 is the ICD-10-CM diagnosis code for inflammatory disease of prostate, unspecified. It belongs to category N41 (inflammatory diseases of prostate), block N40-N53 (diseases of male genital organs) and chapter 14 (diseases of the genitourinary system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within N41, choose N41.9 (Inflammatory disease of prostate, unspecified) only when documentation doesn't support a more specific option: acute prostatitis (N41.0), chronic prostatitis (N41.1), abscess of prostate (N41.2), Prostatocystitis (N41.3), granulomatous prostatitis (N41.4) and other inflammatory diseases of prostate (N41.8).

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

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 727 (Inflammation of the Male Reproductive System with MCC, relative weight 1.37) and DRG 728 (Inflammation of the Male Reproductive System without MCC, relative weight 0.8224), in MDC 12 (Diseases and Disorders of the Male Reproductive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

The Medicare Code Editor expects this diagnosis only for patients age 15 through 124.

It is on the CMS list of diagnoses consistent only with male patients (the sex-conflict edit itself was retired in FY2025).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 601.9 (prostatitis, unspecified).