The N20.0 ICD-10-CM code represents calculus of kidney, commonly referred to as a kidney stone or renal stone. It is a billable and specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
The 2026 edition of ICD-10-CM N20.0 became effective on October 1, 2025. The code is part of the American ICD-10-CM system, so international versions of ICD-10 may differ.
Accurate identification of the applicable diagnosis code is important when documenting and reporting kidney-related conditions. N20.0 specifically identifies calculus of the kidney and includes several terms used to describe kidney stones.
What Is the ICD-10-CM Code for Kidney Stone?
The ICD-10-CM code for calculus of kidney is N20.0.
N20.0 is a billable/specific code, meaning it can be used to indicate a diagnosis for reimbursement purposes. The code is classified under the broader category N20, Calculus of kidney and ureter, within the diseases of the genitourinary system classification.
For the 2026 ICD-10-CM edition, N20.0 became effective on October 1, 2025. The code history provided for N20.0 shows that the code has remained unchanged through the 2026 edition.
N20.0 Code Summary
| Item | Details |
| ICD-10-CM Code | N20.0 |
| Description | Calculus of kidney |
| Code Type | Billable/specific |
| 2026 Effective Date | October 1, 2025 |
| Category | N20 – Calculus of kidney and ureter |
| Chapter | N00-N99 – Diseases of the genitourinary system |
| Applicable Terms | Nephrolithiasis NOS, renal calculus, renal stone, staghorn calculus, stone in kidney |
What Does N20.0 Mean?
N20.0 refers to calculus of kidney. The clinical information associated with this code describes a disorder involving the formation of crystals in the pelvis of the kidney.
In addition, a kidney stone is a solid piece of material that forms in the kidney from substances in the urine. Kidney stones can vary in size, ranging from as small as a grain of sand to as large as a pearl.
Generally, most kidney stones pass out of the body without help from a doctor. However, a stone may sometimes remain in the urinary tract, where it can become stuck and block the flow of urine.
Furthermore, the condition involves the presence of renal calculi, which are abnormal concretions within the kidney and are usually made of mineral salts.
Applicable Terms for N20.0
The ICD-10-CM information for N20.0 lists several terms under Applicable To. These terms include:
-
- Nephrolithiasis NOS
- Renal calculus
- Renal stone
- Staghorn calculus
- Stone in kidney
These terms are useful when reviewing documentation because different terminology may be used to describe calculus of the kidney.
The inclusion of these terms under N20.0 helps connect the documented terminology with the applicable ICD-10-CM code.
Approximate Synonyms for N20.0
The ICD-10-CM information also lists several approximate synonyms associated with N20.0. These include:
-
- Calculus of kidney (kidney stone)
- Kidney stone
- Staghorn calculus
- Staghorn calculus (kidney stone)
- Uric acid nephrolithiasis
- Uric acid renal calculus
These terms provide additional terminology associated with the N20.0 classification.
Clinical Information Associated With N20.0
The clinical information describes N20.0 as a condition involving the formation of crystals in the pelvis of the kidney.
Kidney stones form from substances in the urine and can vary in size. The clinical description states that stones are usually formed in the urine-collecting area of the kidney, known as the kidney pelvis.
The provided clinical information also states that most kidney stones contain calcium oxalate.
Another description included with N20.0 refers to the condition as the formation of stones in the kidney.
When Kidney Stones May Require Medical Help
The clinical information notes that most kidney stones pass from the body without assistance from a doctor. However, a stone can sometimes become stuck in the urinary tract and block the flow of urine.
The following are listed as signs of kidney stones that may require a doctor’s help:
-
- Extreme pain in the back or side that does not go away
- Blood in the urine
- Fever and chills
- Vomiting
- Urine that smells bad or looks cloudy
- A burning feeling when urinating
These signs are included in the clinical information associated with the N20.0 code.
N20.0 Code Hierarchy
N20.0 is located within the broader N20 category. The code hierarchy provided for N20.0 is:
N00-N99 – Diseases of the genitourinary system
Within this classification:
N20 – Calculus of kidney and ureter
And:
N20.0 – Calculus of kidney
The N20 category is identified as one of the code categories that may contain annotation back-references applicable to N20.0.
This hierarchy helps place N20.0 within the broader ICD-10-CM classification of diseases of the genitourinary system.
N20.0 and Diagnostic Related Groups
ICD-10-CM N20.0 is grouped within the following Diagnostic Related Groups (MS-DRG v43.0):
| MS-DRG | Description |
| 693 | Urinary stones with MCC |
| 694 | Urinary stones without MCC |
These DRG classifications are included in the ICD-10Data information associated with N20.0.
N20.0 Code History
The code history provided for N20.0 shows that the code was introduced in 2016, with an effective date of October 1, 2015.
Since then, the code has remained unchanged through the 2026 edition.
| ICD-10-CM Edition | Effective Date | Status |
| 2016 | October 1, 2015 | New code |
| 2017 | October 1, 2016 | No change |
| 2018 | October 1, 2017 | No change |
| 2019 | October 1, 2018 | No change |
| 2020 | October 1, 2019 | No change |
| 2021 | October 1, 2020 | No change |
| 2022 | October 1, 2021 | No change |
| 2023 | October 1, 2022 | No change |
| 2024 | October 1, 2023 | No change |
| 2025 | October 1, 2024 | No change |
| 2026 | October 1, 2025 | No change |
Therefore, according to the supplied information, N20.0 has had no code change for the 2026 edition.
Code Annotations Associated With N20.0
The provided ICD-10-CM information includes several code annotations containing back-references to N20.0.
These include:
- Code Also: E20.810
- Type 1 Excludes: E79
- Type 2 Excludes: N21.0
These annotations provide additional coding information for N20.0 and should guide the review of the code and related documentation.
Diagnosis Index Entries Related to N20.0
The supplied information also contains several Diagnosis Index entries with back-references to N20.0.
These include terminology associated with:
- Abscess of the kidney with calculus
- Calculus or calculi of the kidney
- Kidney calculus
- Impacted kidney calculus
- Multiple kidney calculi
- Pelvic kidney calculus
- Recurrent kidney calculus
- Staghorn calculus
- Pyelitis with calculus
- Infection of the kidney with calculus
- Kidney stone
- Renal stone
The Diagnosis Index provides additional terminology that leads back to the N20.0 classification.
N20.0 and Reimbursement
N20.0 is a billable and specific ICD-10-CM code that healthcare professionals can use to report a diagnosis for reimbursement purposes.
In addition, reimbursement claims with a date of service on or after October 1, 2015, require ICD-10-CM codes.
Therefore, healthcare professionals can use N20.0 when the documented diagnosis corresponds to calculus of the kidney.
Because N20.0 is a specific billable code, accurate coding is an important part of the reimbursement process. Medical billing services can support providers with coding, claim submission, and related revenue-cycle activities.
Frequently Asked Questions About N20.0
1. What is N20.0 in ICD-10-CM?
N20.0 is the ICD-10-CM code for calculus of kidney. It is a billable and specific code used to indicate the diagnosis for reimbursement purposes.
2. Is N20.0 a billable code?
Yes. N20.0 is a billable/specific ICD-10-CM code.
3. What is another term for N20.0?
N20.0 may be associated with terms such as kidney stone, renal stone, renal calculus, nephrolithiasis NOS, and staghorn calculus.
4. When did the 2026 N20.0 code become effective?
The 2026 edition of N20.0 became effective October 1, 2025.
5. Has N20.0 changed in the 2026 ICD-10-CM edition?
According to the supplied code history, N20.0 had no change for the 2026 edition.
6. What are the MS-DRGs associated with N20.0?
N20.0 is grouped within MS-DRG 693, Urinary stones with MCC, and MS-DRG 694, Urinary stones without MCC, according to the supplied information.
Conclusion
N20.0 is the ICD-10-CM code for calculus of kidney, including terminology such as kidney stone, renal calculus, renal stone, nephrolithiasis NOS, and staghorn calculus. It is a billable and specific code used to indicate a diagnosis for reimbursement purposes.
The 2026 edition of N20.0 became effective on October 1, 2025, and the supplied code history shows no change to N20.0 in the 2026 edition. The code falls under N20 – Calculus of kidney and ureter, within N00-N99 – Diseases of the genitourinary system.
For coding and reimbursement purposes, the applicable ICD-10-CM code should correspond with the diagnosis documented in the medical record. Additionally, healthcare providers can also use ICD-10 coding servicesto support accurate and compliant coding workflows.
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