N99.510 ICD-10-CM Code: Cystostomy hemorrhage
N99.510 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · HCC coding software
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FY 2026 Apr update / Diseases of the genitourinary system (N00-N99) / Intraoperative and postprocedural complications and disorders of genitourinary system, not elsewhere classified (N99)
N99.510
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceCystostomy hemorrhage
Bleeding occurs from a cystostomy, which is a surgically created opening in the bladder for urine drainage. This is an abnormal loss of blood from the stoma site.
Buddy Insight
Cystostomy hemorrhage represents a serious complication of urinary diversion procedures that can lead to significant blood loss and hemodynamic instability.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
MappedHCC 176
RAF 0.582
ACA/HHS
N/A—
Not mapped
ESRD/PACE
MappedHCC 176
RAF 0.000
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for N99.510 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for N99.510 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for N99.510 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for N99.510 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for N99.510 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for N99.510 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for N99.510 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is N99.510 an HCC code?
Yes. N99.510 maps to Complications of Specified Implanted Device or Graft under the V24 model but is not retained in V28.
- Code
- N99.510
- Description
- Cystostomy hemorrhage
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work N99.510 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for N99.510
For N99.510 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed N99.510 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
N99.510 is the ICD-10-CM diagnosis code for cystostomy hemorrhage. Bleeding occurs from a cystostomy, which is a surgically created opening in the bladder for urine drainage. This is an abnormal loss of blood from the stoma site. N99.510 sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering intraoperative and postprocedural complications and disorders of genitourinary system, not elsewhere classified (n99).
Under the older CMS-HCC V24 model, N99.510 maps to Complications of Specified Implanted Device or Graft (HCC 176) with a community, non-dual, aged base RAF weight of 0.582. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Verify that a cystostomy is present and documented in the medical record. Because N99.510 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for N99.510 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify that a cystostomy is present and documented in the medical record
- •Distinguish between minor oozing and significant hemorrhage for severity assessment
Clinical Significance
Cystostomy hemorrhage represents a serious complication of urinary diversion procedures that can lead to significant blood loss and hemodynamic instability. This complication requires prompt recognition and intervention, and impacts both immediate care needs and long-term management planning.
Documentation Requirements
- ✓Evidence of active bleeding from cystostomy site
- ✓Documentation of cystostomy procedure and indication
- ✓Assessment of blood loss severity and hemodynamic impact
- ✓Laboratory values showing anemia or coagulation abnormalities
- ✓Intervention records (conservative vs surgical management)
- ✓Relationship between bleeding and device complications
- ✓Monitoring and follow-up care documentation
- ✓Exclusion of other bleeding sources
Commonly Confused Codes
- •N99.511: Cystostomy infection (infection vs hemorrhage complication)
- •R31.9: Hematuria, unspecified (blood in urine vs stoma bleeding)
- •K92.2: Gastrointestinal hemorrhage (different anatomical source)
- •N99.518: Other cystostomy complications (mechanical vs hemorrhagic)
- •T83.038A: Leakage of other urinary catheter (device problem vs bleeding)