Crystal's Coder Hub🧬 ICD-10 CM Z94.0 — Kidney Transplant Status
Billable Code Confirmed
ICD-10 CM Z94.0 is a valid, billable 4-character ICD-10-CM code for FY2026. Characters 1-3 (
Z94) define the transplanted organ and tissue status category; character 4 (.0) specifies the kidney as the transplanted organ. No additional characters are required — Z94.0 is the fully specified, terminal billable code. 1
Non-Billable Parent Codes — Never Submit These
- ❌
Z94— 3-character header — does not specify which organ was transplanted; organ identity must be captured at the 4th characterAlways submit Z94.0 (all 4 characters) when kidney transplant status is documented without an active transplant complication.
Clinical Context: Transplant Status vs. Transplant Complication
ICD-10 -CM Z94.0 captures a functioning kidney transplant in the absence of a documented complication — it is a status code, not a complication code. Per Excludes 1, Z94.0 cannot be coded simultaneously with T86.1x (kidney transplant complications). However, Z94.0 may and should be coded alongside chronic kidney disease (N18.x) when post-transplant CKD is present without an active complication, per Official Guidelines Section I.C.14.a. 1 2
Code Classification
ICD-10 CM Diagnosis Code — wRVU, assistant-at-surgery payable status, and global period fields are not applicable to this diagnosis code. For associated inpatient procedure codes, refer to the ICD-10-PCS Crosswalk section. For associated professional fee billing, refer to the Commonly Associated CPT Codes section.
🔍 Code Description
ICD-10 CM Z94.0 classifies kidney transplant status — indicating that a patient is living with a functioning transplanted kidney (renal allograft) in the absence of a documented complication or rejection episode. 1 This is a Z-code (Chapter 21), meaning it captures a health status factor rather than an active disease; it is assigned as an additional code to provide clinical context when the transplant history is relevant to the encounter. 1
Kidney transplants are the most common solid organ transplants performed in the United States, with more than 27,000 transplants performed annually. 6 Recipients require lifelong immunosuppression to prevent rejection, placing them at substantially elevated risk for opportunistic infections, post-transplant lymphoproliferative disorder, calcineurin inhibitor nephrotoxicity, and cardiovascular events. 5 Accurate documentation and capture of Z94.0 on inpatient claims is essential to reflect the full comorbidity burden, support risk-adjusted reimbursement, and satisfy annual HCC recapture requirements under CMS-HCC v28. 3
🌳 Code Tree / Hierarchy
Z94 — Transplanted organ and tissue status ❌ Non-billable
│
├── Z94.0 — Kidney transplant status ◀ THIS CODE ✅ Billable
├── Z94.1 — Heart transplant status ✅ Billable
├── Z94.2 — Lung transplant status ✅ Billable
├── Z94.3 — Heart and lungs transplant status ✅ Billable
├── Z94.4 — Liver transplant status ✅ Billable
├── Z94.5 — Skin transplant status ✅ Billable
├── Z94.6 — Bone transplant status ✅ Billable
├── Z94.7 — Corneal transplant status ✅ Billable
└── Z94.8 — Other transplanted organ and tissue status ❌ Non-billable subcategory
├── Z94.81 — Bone marrow transplant status ✅ Billable
├── Z94.82 — Intestine transplant status ✅ Billable
├── Z94.83 — Pancreas transplant status ✅ Billable
├── Z94.84 — Stem cell transplant status ✅ Billable
└── Z94.89 — Other transplanted organ and tissue status ✅ Billable
"History of Kidney Transplant" = Current Status, Not Past History
When a provider documents “history of kidney transplant,” “s/p renal transplant,” or “patient with transplanted kidney,” Z94.0 is appropriate — the phrase “history of” in the Z-code context denotes current status (the transplanted organ is present and functioning), not a resolved condition. Do not route this to the personal history category (Z87.x). 1
✅ Includes
The following clinical terms and scenarios map to Z94.0 when documented:
- “Status post kidney transplant” — functioning graft, no complication documented
- “Status post renal transplant” / “s/p renal transplant”
- “Renal transplant status” / “renal allograft status (functioning)”
- “Post-renal transplant — no rejection or complication”
- “Living with transplanted kidney”
- “Kidney transplant patient” — when no complication is documented or queried
❌ Excludes
Excludes 1 — Cannot Be Coded Simultaneously with Z94.0
| Code | Description | Note |
|---|---|---|
| T86.10 | Unspecified complication of kidney transplant | If any complication is present, code T86.1x instead; Z94.0 status is excluded — the T86 code implies the transplant |
| T86.11 | Kidney transplant rejection | T-cell mediated or antibody-mediated rejection — code T86.11 only; omit Z94.0 |
| T86.12 | Kidney transplant failure | Transplant graft failure/non-function — code T86.12 only; omit Z94.0 |
| T86.13 | Kidney transplant infection | Infection involving the transplanted kidney — code T86.13 only; omit Z94.0 |
| T86.19 | Other complication of kidney transplant | Other specified transplant complication — code T86.19 only; omit Z94.0 |
Excludes 1 Violation Risk
The most common Excludes 1 error occurs when a coder assigns both Z94.0 and a T86.1x code for an admission with a documented kidney transplant complication such as biopsy-confirmed rejection. Because these codes are mutually exclusive per Excludes 1, the correct action is to assign only the specific T86.1x complication code — the transplant history is captured implicitly within the T86 code structure. Submitting both triggers an edit that may trigger a claim denial or audit recoupment. 1 2
Excludes 2 — May Be Coded in Addition if Separately Present
| Code | Description | Note |
|---|---|---|
| N18.1-N18.6 | Chronic kidney disease, Stages 1-6 | Per Official Guidelines I.C.14.a, post-transplant CKD is NOT a transplant complication; code the appropriate N18.x stage AND Z94.0 together 2 |
| N18.9 | Chronic kidney disease, unspecified | Use when CKD is documented but stage is not specified; still code with Z94.0 if no active complication |
📋 Clinical Overview
Transplant Status vs. Transplant Complication vs. Post-Transplant CKD — Code Selection Guide
These three coding pathways are the most commonly confused scenarios involving [[Z94.0]] in the inpatient and profee settings. Clinical context and documentation language determine which code(s) apply, and the difference has direct DRG and HCC implications. 1 2
| Feature | Z94.0 — Transplant Status | T86.10-T86.19 — Transplant Complication | N18.x + Z94.0 — Post-Transplant CKD |
|---|---|---|---|
| Transplant present | Yes — functioning graft | Yes — graft with active complication | Yes — functioning graft |
| Active complication | None documented | Yes (rejection, failure, infection) | No — CKD alone ≠ complication |
| Code Z94.0? | ✅ Yes | ❌ No — Excludes 1 | ✅ Yes, as additional code |
| Sequencing | Secondary/additional only | Principal or secondary per circumstance | N18.x as principal or secondary; Z94.0 as additional |
| DRG impact when secondary | CC — upgrades DRG tier | Principal drives DRG; complication code may not allow Z94.0 | N18.x drives DRG; Z94.0 adds CC credit |
| Typical trigger phrase | ”s/p renal transplant,” “functioning graft" | "Rejection,” “graft failure,” “biopsy-confirmed rejection" | "Post-transplant CKD, Stage 3” |
CDI Query Trigger — Ambiguous Post-Transplant Renal Documentation
When a kidney transplant patient is admitted with declining creatinine or worsening renal function and documentation reads “post-transplant kidney disease,” “renal insufficiency in transplant patient,” or “transplant nephropathy” without further specificity, a CDI query must be initiated before coding: “Does the patient’s renal dysfunction represent an active complication of the transplant (rejection or failure — T86.1x), or does it represent chronic kidney disease in the context of transplant status that is not currently a complication (N18.x + Z94.0)? If CKD, please document the stage.” The answer determines whether Z94.0 is assignable and fundamentally changes both DRG grouping and HCC capture. 1 2
Common Manifestations and Comorbidities in Kidney Transplant Patients
Transplant recipients present with a characteristic comorbidity cluster driven by chronic immunosuppression and altered graft physiology. When the following are separately documented and clinically managed, code them in addition to Z94.0: 5
- Chronic Kidney Disease (N18.x): Most transplant recipients have some degree of CKD — code the documented stage alongside Z94.0 per Official Guidelines I.C.14.a 2
- Post-transplant hypertension (I10): Extremely common due to calcineurin inhibitor use and residual nephropathy from the donor organ
- Post-transplant diabetes mellitus: Steroid-induced or calcineurin inhibitor-associated; affects up to 20-30% of recipients — code to the applicable diabetes category with the appropriate manifestation code 5
- CMV infection/disease (B25.9): A major opportunistic infection in the immunosuppressed transplant recipient; requires separate coding when documented and treated
- Anemia (D64.9): Common secondary to CKD, chronic inflammation, and immunosuppressant effects; code when documented and managed
Coding Manifestations
Always code the documented manifestations to fully capture the patient’s complexity. Examples include:
- N18.31 — CKD, Stage 3a (common mid-range post-transplant function)
- N18.4 — CKD, Stage 4 (severe; often a CDI query opportunity for stage specificity)
- I10 — Essential hypertension (extremely common in transplant patients; code if documented)
- D64.9 — Anemia, unspecified (code if documented and clinically managed during the encounter)
💰 HCC Risk Adjustment (CMS-HCC v28)
| Field | Detail |
|---|---|
| CMS-HCC Model Version | v28 (2024-2025 Implementation) |
| HCC Assignment | ✅ Mapped — Kidney Transplant Status hierarchy (verify current HCC number; formerly HCC 136 under v24) |
| HCC Category | Kidney Transplant Status / Renal Disease Hierarchy |
| RAF Coefficient | ~0.39-0.57 (verify against current CMS v28 published coefficients; varies by demographic and enrollment status) |
Z94.0 maps to an HCC under CMS-HCC v28 within the renal disease and transplant status hierarchy. Kidney transplant patients have consistently elevated predicted costs due to lifelong immunosuppression, rejection monitoring, graft function surveillance, and management of transplant-related comorbidities — all reflected in the RAF coefficient assigned to this category. 3
Capture Annually
For Medicare Advantage enrollees, Z94.0 must be supported by a face-to-face clinical encounter and documented at least once per calendar year to persist in the risk adjustment model. Missing Z94.0 annually can suppress the RAF score by 0.39 or more points per beneficiary, leading to systematic underpayment for MA plans managing post-transplant populations. CDI and coding teams should flag any transplant patient encounter where Z94.0 is absent from the claim. 3
🏥 MS-DRG Assignment
MDC 11 — Diseases and Disorders of the Kidney and Urinary Tract
| DRG | Title | Est. Relative Weight* |
|---|---|---|
| DRG 698 | Other Kidney and Urinary Tract Diagnoses with MCC | ~1.40-1.80 |
| DRG 699 | Other Kidney and Urinary Tract Diagnoses with CC | ~0.90-1.10 |
| DRG 700 | Other Kidney and Urinary Tract Diagnoses without CC/MCC | ~0.70-0.90 |
Approximate. Verify against IPPS FY2026 Final Rule tables.
Sequencing and DRG Impact
Z94.0 is not a principal diagnosis — it is always an additional/secondary code. When coded as a secondary diagnosis in appropriate contexts, Z94.0 functions as a CC, upgrading the DRG from the “without CC/MCC” tier to the “with CC” tier and meaningfully improving the relative weight. For admissions driven by active transplant complications (T86.1x as principal), Z94.0 is excluded per Excludes 1 and should not be coded. For routine aftercare post-transplant, Z48.22 (Encounter for aftercare following kidney transplant) is the correct principal diagnosis, with Z94.0 as an appropriate additional code; this combination routes to MDC 11 DRG 698-700 depending on additional comorbidities. 1 4
🔗 Related ICD-10-CM Codes
Kidney Transplant Complication Codes — Excludes 1 with Z94.0
| Code | Description |
|---|---|
| Z94.0 | Kidney transplant status ← This Code |
| T86.10 | Unspecified complication of kidney transplant |
| T86.11 | Kidney transplant rejection |
| T86.12 | Kidney transplant failure |
| T86.13 | Kidney transplant infection |
| T86.19 | Other complication of kidney transplant |
Post-Transplant CKD — Codes Reportable Alongside Z94.0
| Code | Description |
|---|---|
| N18.1 | Chronic kidney disease, Stage 1 |
| 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 |
Transplant Aftercare and Related Organ Status Codes
| Code | Description |
|---|---|
| Z48.22 | Encounter for aftercare following kidney transplant — correct principal code for post-transplant monitoring admissions |
| Z94.83 | Pancreas transplant status — applicable for simultaneous kidney-pancreas transplant recipients |
| Z94.1 | Heart transplant status |
| Z94.4 | Liver transplant status |
🛠️ Commonly Associated CPT Codes (Urology / Transplant Surgery)
Inpatient and Profee Setting Context
The CPT codes below are associated with kidney transplant patients in both inpatient facility and profee billing settings. Transplant patients are typically co-managed by urology, nephrology, and transplant surgery teams across multiple admissions over their lifetime. Transplant procedure CPT codes (50360, 50365) apply at the time of the original transplant; post-transplant monitoring and intervention codes (50200, 93975, 93976) apply to subsequent admissions and clinic encounters.
| CPT Code | Description | Profee Coding Notes (Modifier 26) |
|---|---|---|
| 50360 | Renal allotransplantation, implantation of graft; without recipient nephrectomy | Surgical CPT for the transplant procedure itself; creates Z94.0 status post-operatively |
| 50365 | Renal allotransplantation; with recipient nephrectomy | When simultaneous native kidney removal is performed at time of transplant |
| 50370 | Removal of transplanted renal allograft | Transplant nephrectomy for graft failure; do not report with 50360 or 50365 for the same organ in the same session |
| 50380 | Renal autotransplantation; reimplantation of kidney | Autologous graft — not allograft; used in ureteral injury or renovascular disease scenarios |
| 50200 | Renal biopsy; percutaneous, by trocar or needle | Primary diagnostic procedure for rejection workup; most frequently performed post-transplant inpatient procedure |
| 93975 | Duplex scan of arterial inflow and venous outflow; complete study, retroperitoneal | Transplant kidney Doppler evaluation; append modifier -26 in the facility setting for the profee component |
| 93976 | Duplex scan; unilateral or limited study | Use when only the transplant kidney is evaluated rather than bilateral/complete retroperitoneal study |
| 76942 | Ultrasonic guidance for needle placement, imaging supervision and interpretation | Separately reportable with 50200 when real-time ultrasound guidance is distinctly documented with supervision and interpretation |
NCCI Bundling Considerations
- Transplant nephrectomy (50370) billed on the same day as transplantation (50360 or 50365) for the same organ constitutes a bundling violation — these are intended for distinct organs or separate operative encounters
- Renal biopsy (50200) and ultrasound guidance (76942) are separately reportable when real-time guidance documentation includes supervision and interpretation; payers may bundle if documentation is insufficient — ensure the operative note specifically documents image-guided needle placement
- Duplex scan (93975) and a standalone renal ultrasound on the same date may be subject to NCCI edits — confirm modifier -59 applicability per individual payer policy before billing both
🔬 ICD-10-PCS Crosswalk (Inpatient Procedures)
When Z94.0 is an inpatient secondary diagnosis, the following ICD-10-PCS codes are relevant for associated inpatient procedures performed in kidney transplant patients. 4
| PCS Section | Body System | Root Operation | Clinical Application |
|---|---|---|---|
| 0 (Medical and Surgical) | T (Urinary System) | Y (Transplantation) | Original allograft creating the Z94.0 status: Right kidney 0TY00Z0, Left kidney 0TY10Z0 (Allogeneic, Open Approach) |
| 0 (Medical and Surgical) | T (Urinary System) | B (Excision) | Percutaneous transplant biopsy for rejection workup: 0TB03ZX (Right, Percutaneous, Diagnostic) / 0TB13ZX (Left, Percutaneous, Diagnostic) |
| 5 (Extracorporeal/Systemic Assistance and Performance) | A (Physiological Systems) | 1 (Performance) | Hemodialysis for failing transplant: 5A1D70Z (Urinary Filtration, Intermittent, <6 Hours/Day) |
| 0 (Medical and Surgical) | T (Urinary System) | T (Resection) | Transplant nephrectomy for graft failure: 0TT00ZZ (Resection of Right Kidney, Open Approach) |
💊 Coding Scenarios and Examples
Scenario 1 — Inpatient: Post-Transplant CKD — Correctly Coding N18.x Alongside Z94.0
Clinical Vignette: A 58-year-old male with a living-donor kidney transplant 4 years ago is admitted for urinary tract infection with urosepsis. Creatinine on admission is 2.1 mg/dL. Nephrology is consulted and documents: “Stage 3a CKD in the context of his kidney transplant — no evidence of acute rejection on current labs; the CKD represents his expected post-transplant baseline and is not a transplant complication.” The patient is treated with IV antibiotics and improves over 5 days.
Principal Diagnosis:
- N39.0 — Urinary tract infection, site not specified (reason for admission — urosepsis from UTI)
Secondary Diagnoses:
- A41.9 — Sepsis, unspecified organism (MCC — drives DRG upgrade)
- N18.31 — Chronic kidney disease, Stage 3a (documented by nephrology; NOT a transplant complication per Official Guidelines I.C.14.a) 2
- Z94.0 — Kidney transplant status (appropriately coded alongside N18.31; CKD alone does not exclude Z94.0; functions as CC) 2
MS-DRG Assignment: With A41.9 (sepsis — MCC) as secondary, the encounter routes to a sepsis DRG in MDC 18 rather than MDC 11. Z94.0 contributes a CC, though the MCC from sepsis already drives the highest DRG tier.
Scenario 2 — Inpatient: Kidney Transplant Rejection — Excludes 1 Applied
Clinical Vignette: A 44-year-old female with a deceased-donor kidney transplant 2 years ago is admitted with rising creatinine and new-onset hypertension. A percutaneous transplant biopsy performed under ultrasound guidance confirms T-cell mediated acute rejection, Grade IIA. The patient is treated with high-dose pulse corticosteroids and plasmapheresis over a 6-day inpatient stay.
Principal Diagnosis:
- T86.11 — Kidney transplant rejection (biopsy-confirmed T-cell mediated rejection — reason for admission)
Secondary Diagnoses:
- I10 — Essential hypertension (comorbidity documented and managed during admission)
- ❌
Z94.0— DO NOT CODE — Z94.0 is excluded per Excludes 1 when any T86.1x code is assigned; the complication code implies transplant history 1
Inpatient Procedures (ICD-10-PCS):
- 0TB03ZX — Excision of Right Kidney, Percutaneous, Diagnostic (transplant biopsy)
MS-DRG Assignment: T86.11 as principal → MDC 11 → DRG 699 (Other Kidney and Urinary Tract Diagnoses with CC from I10), or DRG 698 if an additional MCC is documented.
Scenario 3 — CDI Query: “Post-Transplant Kidney Disease” — Ambiguous Documentation
Clinical Vignette: A 63-year-old male with “kidney transplant 6 years ago” is admitted for volume overload and worsening renal function. The attending documents: “post-transplant kidney disease with declining GFR.” Creatinine has risen from 1.8 to 3.2 mg/dL over 3 months per outpatient records. No biopsy is performed during this admission. The attending also notes “patient may have some chronic changes” without specifying rejection, failure, or CKD stage.
Action / Outcome: The documentation “post-transplant kidney disease” is ambiguous — it could represent (1) CKD post-transplant (N18.x + Z94.0) or (2) an active transplant complication such as chronic rejection or graft failure (T86.11 or T86.12). A CDI query must be initiated before coding: “Does the patient’s worsening renal function represent chronic kidney disease in the context of kidney transplant status — not a transplant complication — or does it represent an active complication of the kidney transplant such as rejection or graft failure? If CKD, please document the current stage.” These two pathways are mutually exclusive; Z94.0 can only be coded in the absence of a concurrent T86.1x code. 1 2
Query Response: Provider clarifies: “This is CKD, Stage 4, representing the patient’s baseline post-transplant nephropathy — there is no evidence of acute rejection or active graft failure at this time. Please note CKD Stage 4.”
Corrected ICD-10-CM Coding:
- N18.4 — Chronic kidney disease, Stage 4 (principal or secondary per admission context)
- Z94.0 — Kidney transplant status (additional code — appropriately coded alongside CKD with no active complication) 2
- ❌
T86.12— Not coded — no transplant complication confirmed after CDI clarification
⚠️ Coding Pitfalls and Tips
| Pitfall or Tip | |
|---|---|
| ❌ | Coding Z94.0 simultaneously with T86.1x. Assigning both Z94.0 (transplant status) and any T86.1x (transplant complication) is an Excludes 1 violation. When a kidney transplant complication is documented, assign the specific T86.1x code only — the transplant history is implied within the T86 structure. 1 |
| ❌ | Omitting Z94.0 when post-transplant CKD is present. Post-transplant CKD (N18.x) is explicitly NOT a transplant complication and does not trigger Excludes 1. Dropping Z94.0 when it should be coded alongside N18.x loses a CC, suppresses the HCC, and understates clinical complexity. 2 |
| ❌ | Sequencing Z94.0 as the principal diagnosis. Z94.0 is a status code and should never be the principal. If the primary reason for admission is post-transplant monitoring or aftercare, sequence Z48.22 as principal and Z94.0 as additional. 1 |
| ✅ | Query when documentation is vague between CKD and rejection. Documentation such as “post-transplant kidney disease,” “transplant nephropathy,” or “declining renal function in transplant patient” requires a CDI query before coding — the difference between N18.x + Z94.0 vs. T86.1x alone changes the DRG tier and determines whether Z94.0 is billable at all. 2 |
| ✅ | Recapture Z94.0 annually for Medicare Advantage patients. Annual documentation and coding of Z94.0 on at least one face-to-face encounter is required to maintain the HCC in the v28 risk adjustment model. Implement a systematic audit to identify transplant patients whose Z94.0 status was not captured in the current calendar year. 3 |
| ✅ | Code CKD stage specifically — never default to N18.9 if the stage is documented. When a transplant patient’s CKD stage is documented by the provider, always assign the most specific N18.x code (N18.1-N18.6). Defaulting to N18.9 (unspecified) when a stage is available leaves HCC specificity and DRG opportunity on the table. 1 2 |
📚 Sources
1. CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026. Centers for Medicare and Medicaid Services; National Center for Health Statistics.
2. CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.14.a — Chronic kidney disease and kidney transplant complications. Pages 62-63.
3. CMS. 2024-2025 Medicare Advantage Risk Adjustment: CMS-HCC Model v28 ICD-10-CM Mappings. Centers for Medicare and Medicaid Services, Center for Medicare, Risk Adjustment Group.
4. CMS. IPPS Final Rule FY2026 — MS-DRG Definitions Manual v43. MDC 11 — Diseases and Disorders of the Kidney and Urinary Tract. Logic tables and DRG weights.
5. Kidney Disease: Improving Global Outcomes (KDIGO) Transplant Work Group. KDIGO Clinical Practice Guideline for the Care of Kidney Transplant Recipients. Am J Transplant. 2009;9(Suppl 3):S1-S155. Updated guidance: KDIGO 2022.
6. Organ Procurement and Transplantation Network / Scientific Registry of Transplant Recipients (OPTN/SRTR). 2022 Annual Data Report: Kidney. U.S. Department of Health and Human Services, Health Resources and Services Administration. https://srtr.transplant.hrsa.gov
7. AMA. CPT Professional Edition 2026. Surgery — Urinary System (CPT codes 50010-53899). American Medical Association.