ICD-10-CM 2027 diagnosis code

N30Cystitis

Not billable — use a more specific code

N30 is a header code, so it can't be reported by itself. Choose one of the 7 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About N30

N30 is the ICD-10-CM diagnosis code for cystitis. It belongs to block N30-N39 (other diseases of the urinary system) and chapter 14 (diseases of the genitourinary system). It is a header code, so it can't be reported by itself; one of its 7 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: N30.0 (cystitis), N30.1 ((chronic)), N30.2 (cystitis), N30.3 (Trigonitis), N30.4 (cystitis), N30.8 (cystitis) and N30.9 (unspecified).

Don't report N30 together with the conditions in its Excludes1 note: prostatocystitis (N41.3).

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

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

Specific codes under N30

Coding notes

Excludes1Not coded here — never report together with this code

prostatocystitis (N41.3)

Use additional codeAdd a secondary code to fully describe the condition

code to identify infectious agent (B95-B97)

Notes that apply from higher levels

Instructions written at a parent level also apply to N30.

Broader instructions also apply from N30-N39 Other diseases of the urinary system and Chapter 14: Diseases of the genitourinary system.

Codes whose notes reference N30

N39.0Excludes1

Code history

2016
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2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about N30

Is N30 billable?: No. N30 is a header code. Report one of its more specific subcodes instead.