N21.0 — Calculus in bladder
Is N21.0 billable?
Yes — N21.0 is billable for FY2027. N21.0 is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. N21.0 may be submitted for encounters from October 1, 2026 through September 30, 2027.
N21.0 at a glance
| Code | N21.0 |
|---|---|
| Description | Calculus in bladder |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does N21.0 group to?
N21.0 sits in MDC 11 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 693Urinary Stones with MCCmedical
- 694Urinary Stones without MCCmedical
How is N21.0 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to N21.0. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Cystolithiasis
- Calculus, calculi, calculous › bladder
- Calculus, calculi, calculous › cystic
- Calculus, calculi, calculous › vesical
- Cystitis › calculous (exudative) (hemorrhagic) (septic) (suppurative)
- Stone › bladder (s)
- Calculus, calculi, calculous › diverticulum › bladder
- Stone › urinary › bladder (s)
Excludes2 — not included here
The conditions below are not part of N21.0, but a patient may have both at the same time. When documentation supports it, N21.0 and the excluded code may both be reported.
- staghorn calculus (N20.0)
Inclusion terms
Alternative wording in documentation that is classified to N21.0.
- Calculus in diverticulum of bladder
- Urinary bladder stone
Excludes2 — not included here — inherited from Chapter 14
The conditions below are not part of N21.0, but a patient may have both at the same time. When documentation supports it, N21.0 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
How long has N21.0 existed?
N21.0 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.