N18.1: Chronic kidney disease, stage 1
N18.1, chronic kidney disease, stage 1, is listed as a covered diagnosis in 9 Medicare billing and coding articles that apply to 19 HCPCS Level II codes, including G0127 (Trimming of dystrophic nails, any number), C8900 (Magnetic resonance angiography with contrast, abdomen), C8901 (Magnetic resonance angiography without contrast, abdomen). The articles come from 6 Medicare contractors. A listed diagnosis supports medical necessity only; coverage still depends on the LCD's criteria and on documentation in the medical record.
HCPCS Level II codes with N18.1 as a covered diagnosis
| Code | Description | Medicare coverage | DMEPOS fee 2026 (state range) | Articles listing it |
|---|---|---|---|---|
| G0127 | Trimming of dystrophic nails, any number | Special coverage instructions apply | — | 6 |
| C8900 | Magnetic resonance angiography with contrast, abdomen | Special coverage instructions apply | — | 3 |
| C8901 | Magnetic resonance angiography without contrast, abdomen | Special coverage instructions apply | — | 3 |
| C8902 | Magnetic resonance angiography without contrast followed by with contrast, abdomen | Special coverage instructions apply | — | 3 |
| C8909 | Magnetic resonance angiography with contrast, chest (excluding myocardium) | Special coverage instructions apply | — | 3 |
| C8910 | Magnetic resonance angiography without contrast, chest (excluding myocardium) | Special coverage instructions apply | — | 3 |
| C8911 | Magnetic resonance angiography without contrast followed by with contrast, chest (excluding myocardium) | Special coverage instructions apply | — | 3 |
| C8912 | Magnetic resonance angiography with contrast, lower extremity | Special coverage instructions apply | — | 3 |
| C8913 | Magnetic resonance angiography without contrast, lower extremity | Special coverage instructions apply | — | 3 |
| C8914 | Magnetic resonance angiography without contrast followed by with contrast, lower extremity | Special coverage instructions apply | — | 3 |
| C8918 | Magnetic resonance angiography with contrast, pelvis | Special coverage instructions apply | — | 3 |
| C8919 | Magnetic resonance angiography without contrast, pelvis | Special coverage instructions apply | — | 3 |
| C8920 | Magnetic resonance angiography without contrast followed by with contrast, pelvis | Special coverage instructions apply | — | 3 |
| C8931 | Magnetic resonance angiography with contrast, spinal canal and contents | Special coverage instructions apply | — | 2 |
| C8932 | Magnetic resonance angiography without contrast, spinal canal and contents | Special coverage instructions apply | — | 2 |
| C8933 | Magnetic resonance angiography without contrast followed by with contrast, spinal canal and contents | Special coverage instructions apply | — | 2 |
| C8934 | Magnetic resonance angiography with contrast, upper extremity | Special coverage instructions apply | — | 2 |
| C8935 | Magnetic resonance angiography without contrast, upper extremity | Special coverage instructions apply | — | 2 |
| C8936 | Magnetic resonance angiography without contrast followed by with contrast, upper extremity | Special coverage instructions apply | — | 2 |
Medicare policy articles listing N18.1
- A57759: Billing and Coding: Routine Foot Care and Debridement of Nails (Wellpoint Federal (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L33636, L34246
- A57193: Billing and Coding: Routine Foot Care and Debridement of Nails (CGS Administrators, LLC (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L33636, L34246
- A52996: Billing and Coding: Routine Foot Care (Novitas Solutions, Inc. (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L33941, L35138, L37643
- A56232: Billing and Coding: Foot Care (WPS Insurance Corporation (MAC - Part A, MAC - Part B); 1 Level II codes)
- A57188: Billing and Coding: Routine Foot Care (First Coast Service Options, Inc. (MAC - Part B); 1 Level II codes). LCD with the same title: L33941, L35138, L37643
- A56805: Billing and Coding: Magnetic Resonance Angiography (MRA) (Novitas Solutions, Inc. (MAC - Part A, MAC - Part B); 12 Level II codes). LCD with the same title: L33633, L34372, L34865
- A56680: Billing and Coding: Routine Foot Care (Palmetto GBA (MAC - Part A, MAC - Part B); 1 Level II codes). LCD with the same title: L33941, L35138, L37643
- A56747: Billing and Coding: Magnetic Resonance Angiography (MRA) (Wellpoint Federal (MAC - Part A, MAC - Part B); 18 Level II codes). LCD with the same title: L33633, L34372, L34865
- A56775: Billing and Coding: Magnetic Resonance Angiography (Palmetto GBA (MAC - Part A, MAC - Part B); 18 Level II codes). LCD with the same title: L34424
A diagnosis listed as covered in a billing and coding article supports medical necessity for the article's codes; it does not guarantee payment. Coverage depends on the LCD's criteria, the contractor's jurisdiction and documentation in the medical record.
Other N18 diagnoses (Chronic kidney disease (CKD))
- N18.2 — Chronic kidney disease, stage 2 (mild)
- N18.30 — Chronic kidney disease, stage 3 unspecified
- N18.31 — Chronic kidney disease, stage 3a
- N18.32 — Chronic kidney disease, stage 3b
- N18.4 — Chronic kidney disease, stage 4 (severe)
- N18.5 — Chronic kidney disease, stage 5
- N18.6 — End stage renal disease
- N18.9 — Chronic kidney disease, unspecified
Frequently asked questions
Does Medicare cover N18.1 (Chronic kidney disease, stage 1)?
Medicare covers items and services, not diagnoses. 9 Medicare billing and coding articles list N18.1 as a covered diagnosis for 19 HCPCS Level II codes: the diagnosis can support medical necessity for those codes, but payment still depends on the LCD's coverage criteria and the medical record.
Which HCPCS codes can be billed with ICD-10 N18.1?
The Level II codes from the policies most specific to this diagnosis are G0127 (Trimming of dystrophic nails, any number, 6 articles); C8900 (Magnetic resonance angiography with contrast, abdomen, 3 articles); C8901 (Magnetic resonance angiography without contrast, abdomen, 3 articles); C8902 (Magnetic resonance angiography without contrast followed…, 3 articles); C8909 (Magnetic resonance angiography with contrast, chest…, 3 articles). Code choice depends on the item supplied; check each code's descriptor.
Which Medicare policy articles list N18.1?
A57759 (Billing and Coding: Routine Foot Care and Debridement of Nails); A57193 (Billing and Coding: Routine Foot Care and Debridement of Nails); A52996 (Billing and Coding: Routine Foot Care), and 6 more articles.
What is ICD-10-CM code N18.1?
N18.1 is the ICD-10-CM code for chronic kidney disease, stage 1, in category N18 (Chronic kidney disease (CKD)), chapter 14: Diseases of the genitourinary system.
Next steps
- Run a reimbursement report for a device billed under G0127
- Watch G0127 for fee, coverage and descriptor changes
- Build a full Medicare revenue model for G0127
Sources: CMS Medicare Coverage Database billing and coding articles (covered ICD-10 code lists and HCPCS links); ICD-10-CM FY2026; CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule 2026 (non-rural state fees). Not billing or legal advice.
Chapter 14: Diseases of the genitourinary system · All diagnoses · HCPCS lookup