Billable / Specific Code
ICD-10-CM N21.9 is the diagnosis code for Calculus of lower urinary tract, unspecified. This code falls under the section "Urolithiasis" within Chapter 14 — Diseases of the genitourinary system (N00-N99). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions should never be coded at the same time as N21.9. They are mutually exclusive:
Understanding where N21.9 sits in the ICD-10-CM classification helps ensure proper coding:
Yes, N21.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
N21.9 is the ICD-10-CM diagnosis code for "Calculus of lower urinary tract, unspecified". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of N21.9 is N21 ("Calculus of lower urinary tract"). N21.9 provides a more specific classification within this category.
N21.9 is located in Section N20-N23 — "Urolithiasis" within Chapter 14 of the ICD-10-CM Tabular List.
Use N21.9 when the patients documented diagnosis matches "Calculus of lower urinary tract, unspecified" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Calculus of lower urinary tract, unspecified is N21.9.
Yes, N21.9 can be used as a primary diagnosis code since it is billable and specific.
N21.9 is in Chapter 14 of the ICD-10-CM Tabular List.
Type 1 Excludes for N21.9 include: calculus of urinary tract NOS (N20.9).
Yes, N21.9 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.