Summary: Aetna, a CVS Health company, modified CPB 1099 covering narsoplimab-wuug (Yartemlea), effective May 8, 2026. Here's what billing teams need to know before submitting claims.
Narsoplimab-wuug is a complement inhibitor approved for hematopoietic stem cell transplant-associated thrombotic microangiopathy (HSCT-TMA) — a rare, life-threatening condition with limited treatment options. This CPB 1099 Aetna coverage policy update affects specialty pharmacy billing teams, transplant centers, and oncology practices billing for this drug. The policy does not list specific CPT or HCPCS codes in the available data, so work directly with your specialty pharmacy and payer rep to confirm the correct billing codes before submitting.
| Field | Detail |
|---|---|
| Payer | Aetna, a CVS Health company |
| Policy | Narsoplimab-wuug (Yartemlea) — CPB 1099 |
| Policy Code | CPB 1099 |
| Change Type | Modified |
| Effective Date | 2026-05-08 |
| Impact Level | High |
| Specialties Affected | Oncology, Hematology, Transplant Medicine, Specialty Pharmacy |
| Key Action | Audit your prior authorization workflows for narsoplimab-wuug claims before May 8, 2026 |
Aetna Narsoplimab-wuug Coverage Criteria and Medical Necessity Requirements 2026
The CPB 1099 Aetna system governs how Aetna reviews narsoplimab-wuug (Yartemlea) claims for medical necessity. This drug has a narrow approved indication, and Aetna's coverage policy reflects that narrowness. Expect scrutiny on every claim.
Narsoplimab-wuug received FDA approval specifically for HSCT-TMA in adults and pediatric patients 12 years and older. The real issue here is that HSCT-TMA is rare and historically hard to diagnose, which means documentation requirements will be demanding. Your clinical team needs to establish a clear, documented diagnosis before billing — not after a denial lands.
Based on the FDA-approved indication and standard Aetna coverage policy patterns for specialty biologics in this class, Aetna will evaluate medical necessity against criteria like these:
| # | Covered Indication |
|---|---|
| 1 | Confirmed diagnosis of HSCT-TMA following allogeneic hematopoietic stem cell transplant |
| 2 | Inadequate response to or intolerance of supportive care measures |
| 3 | Treatment ordered or supervised by a hematologist or transplant specialist |
| 4 | Documentation supporting the diagnosis, including laboratory findings consistent with TMA |
Because the policy was modified as of May 8, 2026, any criteria that shifted — tightened documentation requirements, added prior authorization steps, or new exclusions — take effect on that date. Don't assume last year's approval logic still applies. Pull the current version of CPB 1099 directly from Aetna's clinical policy portal and read it against your existing workflows.
Prior authorization is standard for drugs in this class, and narsoplimab-wuug billing almost certainly requires it. If your team has been processing these claims without a current PA confirmation, stop and verify before the effective date of May 8, 2026. A single denied claim on a drug with this price point creates significant reimbursement exposure.
Aetna Narsoplimab-wuug Exclusions and Non-Covered Indications
Because the full policy detail isn't available in the source data, we can't list specific exclusions verbatim from CPB 1099. That's a gap worth flagging — not a reason to guess.
What we do know is that Aetna typically excludes off-label use of specialty biologics unless strong peer-reviewed evidence supports coverage. For narsoplimab-wuug, any indication outside HSCT-TMA — such as use in non-transplant TMA, atypical hemolytic uremic syndrome, or other complement-mediated disorders — is likely not covered under this policy.
Aetna also typically considers a treatment experimental or investigational when it lacks FDA approval for the specific indication being billed. If your clinical team is using Yartemlea outside the HSCT-TMA indication, document your clinical rationale thoroughly and get a coverage determination before billing. A claim denial on an off-label use is hard to overturn without that foundation.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| HSCT-TMA in adults and pediatric patients ≥12 years (FDA-approved indication) | Likely Covered | Not listed in policy data | Prior authorization almost certainly required; confirm with Aetna before billing |
| Off-label use in non-transplant TMA | Likely Not Covered / Experimental | Not listed in policy data | Requires strong clinical evidence and formal coverage determination |
| Use in patients under 12 years | Likely Not Covered | Not listed in policy data | Outside FDA-approved indication; treat as off-label |
| Indication outside complement-mediated disorders | Not Covered | Not listed in policy data | No clinical basis under CPB 1099 |
Note: This table reflects the FDA-approved indication and standard Aetna coverage policy patterns. The full CPB 1099 text may include additional or different criteria. Verify directly with Aetna before submitting claims.
Aetna Narsoplimab-wuug Billing Guidelines and Action Items 2026
This is a high-stakes coverage policy. The drug is expensive, the patient population is small, and a single process gap can produce a large claim denial. Here's what to do before May 8, 2026.
| # | Action Item |
|---|---|
| 1 | Pull the current CPB 1099 policy text from Aetna's clinical policy site. The policy was modified on May 8, 2026. Read the new version against the prior version, line by line. If you don't have access to version diffs, request them from your Aetna provider relations rep. You need to know exactly what changed — not just that something changed. |
| 2 | Verify prior authorization requirements before submitting any narsoplimab-wuug billing. Call Aetna's specialty pharmacy or PA line, or check through Aetna's provider portal. Confirm whether existing PAs carry forward past May 8, 2026, or whether patients currently on therapy need a new authorization under the modified policy. |
| 3 | Audit your diagnosis documentation now. Every claim for narsoplimab-wuug needs to tie directly to a confirmed HSCT-TMA diagnosis, supported by lab findings and specialist notes. If your clinical documentation doesn't clearly establish the diagnosis and the clinical picture, fix it before the claim goes out. Reviewers will look for this. |
| 4 | Confirm billing codes with Aetna directly. The policy data for CPB 1099 does not list specific HCPCS or CPT codes. Narsoplimab-wuug may bill under a J-code or a NOC (not otherwise classified) code depending on current HCPCS assignment. Contact Aetna's provider services to confirm the correct code for claim submission. Using the wrong code on a drug this expensive means a denial and a delay that your transplant patients can't afford. |
| 5 | Check your specialty pharmacy agreements. If your practice bills through a specialty pharmacy arrangement rather than buy-and-bill, confirm that the pharmacy is billing under the correct codes and has the PA in place. Coordination gaps between the practice and pharmacy are a top source of claim denials for drugs like Yartemlea. |
| 6 | Loop in your compliance officer if you're billing off-label. If any of your patients are receiving narsoplimab-wuug outside the HSCT-TMA indication, talk to your compliance officer before the effective date of May 8, 2026. Off-label billing without a solid documentation and coverage determination process is a liability — not just a billing problem. |
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
CPT, HCPCS, and ICD-10 Codes for Narsoplimab-wuug Under CPB 1099
The available policy data for CPB 1099 does not include specific CPT, HCPCS, or ICD-10 codes. Do not infer or assume codes based on drug class alone.
Here's what that means for your billing team:
Confirming the Correct HCPCS Code
Narsoplimab-wuug (Yartemlea) may have a dedicated J-code assigned by CMS after FDA approval, or it may currently bill under a not otherwise classified (NOC) code. NOC codes require additional documentation — including the drug name, dosage, and NDC — to process correctly. A claim submitted under the wrong code, or under an NOC without adequate documentation, will deny on the first pass.
Contact Aetna's provider services line and confirm:
- The specific HCPCS code Aetna accepts for narsoplimab-wuug under CPB 1099
- Whether that code requires a specific modifier
- How Aetna wants the NDC submitted on the claim
ICD-10 Diagnosis Codes
HSCT-TMA doesn't have its own standalone ICD-10-CM code. Your coding team will likely use a combination of codes to capture the diagnosis — including codes for thrombotic microangiopathy, conditions following transplant procedures, and related complications. Work with your coding team or a coding consultant to confirm the right ICD-10 combination for your claims before May 8, 2026. Mismatched diagnosis codes are a fast path to a medical necessity denial.
Because no codes are confirmed in the CPB 1099 policy data, we're not publishing a code table here. Publishing unconfirmed codes would create more risk than it resolves. When Aetna publishes updated billing guidelines with confirmed codes, we'll update this post.
Get the Full Picture
Track this policy across versions, search 1,500+ policies by CPT code, and get real-time alerts when any payer changes coverage.