Phesgo (pertuzumab + trastuzumab + hyaluronidase-zzxf) — HCPCS J9316
CareCost Estimate · Billing Cheat Sheet
Genentech (Roche)
SC fixed-dose combo
Loading 1,200/600 mg in 15 mL · Maintenance 600/600 mg in 10 mL
Reviewed: May 22, 2026
ASP: Q2 2026
HCPCS
J9316
1 unit = 10 mg pert (not 1 mg)
Loading
120 units
1,200/600 mg cycle 1 · SC ~8 min
Maintenance
60 units
600/600 mg q3wk · SC ~5 min
Modifier
JZ
Required (single-dose, no waste)
Medicare ASP+6%
$60.225
/10 mg · $3,613.50 / 600 mg dose
TOP DENIAL: HER2 DOC MISSING. Payers require HER2 IHC 3+ OR IHC 2+/ISH+ (ratio ≥2.0 or copy ≥6.0) in PA submission. Schedule HER2 testing (CPT 88360 IHC / 88374 ISH) BEFORE submitting PA.
#2 DENIAL: PHESGO BILLED AS SPLIT IV COMPONENTS. Phesgo = ONE line of J9316 only. Do NOT bill J9306 (Perjeta) + J9355 (Herceptin) IV components when patient got the SC combo. Different BLA, different NDCs, different J-code.
Codes & NDC
| HCPCS | J9316 — "Pertuzu, trastuzu, 10 mg" (permanent, eff. 7/1/2021; pre-2021 used J3490/J9999) |
|---|
| Loading NDC | 50242-251-01 / 50242-0251-01 — 1,200 mg pert / 600 mg trast / 30,000 U hyaluronidase in 15 mL SDV. N4 qualifier. |
|---|
| Maintenance NDC | 50242-250-01 / 50242-0250-01 — 600 mg pert / 600 mg trast / 20,000 U hyaluronidase in 10 mL SDV. N4 qualifier. |
|---|
| IV components (different J-codes!) | J9306 (Perjeta IV, 1 mg/unit) + J9355 (Herceptin IV, 10 mg/unit) + biosimilars |
|---|
| Benefit | Medicare Part B / commercial medical; provider buy-and-bill |
|---|
Dosing — FIXED FLAT, not weight-based
- Loading (cycle 1): 1,200 mg pert + 600 mg trast + 30,000 U hyaluronidase, ~8 mL SC over 8 min in thigh — bill 120 units J9316
- Maintenance (cycles 2+): 600/600 mg + 20,000 U hyaluronidase, ~5 mL SC over 5 min q3wk — bill 60 units J9316
- Alternate thighs each cycle; do NOT mix with other products in syringe
- Observation: 30 min after loading; 15 min after maintenance
- Missed dose >6 weeks: re-administer loading dose, then resume q3wk
- No pediatric indication — adults only
- Year-1 units total: 120 + (16 × 60) = 1,080 units
Phesgo SC vs Perjeta+Herceptin IV
| Phesgo SC | Perjeta+Herceptin IV |
|---|
| HCPCS | J9316 only (1 line) | J9306 + J9355 (2 lines) |
| Admin CPT | 96401 | 96413 + 96417 |
| Chair time | 5–8 min + 15–30 min obs | 60–150 min combined |
| Loading | 120 units J9316 | 840 units J9306 + ~560 units J9355 (70kg) |
| Maint | 60 units J9316 | 420 units J9306 + ~420 units J9355 (70kg) |
Switching IV → SC: requires new PA most payers; first SC dose is the loading dose (120 units) regardless of prior IV cycle.
Administration & modifiers
| Code | When |
|---|
96401 | Chemo SC, non-hormonal — single billable line for Phesgo (loading or maint) |
96413/96417 | NOT appropriate — those are IV codes for Perjeta+Herceptin |
96372 | NOT appropriate — pertuzumab/trastuzumab is chemo admin, not therapeutic injection |
| JZ: required on virtually every claim (single-dose vial, no waste). JW: rare waste only. One of JZ/JW required since 7/1/2023. |
HER2 testing — required for PA
| Criteria | Action |
|---|
| HER2 IHC 3+ | HER2-positive, no further test needed |
| HER2 IHC 2+ (equivocal) | Reflex FISH/ISH required |
| FISH/ISH ratio ≥2.0 OR copy ≥6.0 | HER2-positive (with IHC 2+) |
| HER2 IHC 0 or 1+ | HER2-negative — not eligible |
| HER2 test | CPT |
|---|
| HER2 IHC (manual) | 88360 |
| HER2 IHC (computer-assisted) | 88361 |
| HER2 FISH (manual / computer) | 88368 / 88369 |
| HER2 ISH (single probe / multiplex) | 88374 / 88377 |
ICD-10 — HER2+ breast (same as IV combo)
| Code | For |
|---|
C50.411 / C50.412 | Upper-outer quadrant R / L |
C50.111 / C50.112 | Central portion R / L |
C50.811 / C50.812 | Overlapping sites R / L |
C50.919 | Female, NOS (avoid; use specific) |
C77.3 | Axillary/regional nodal mets |
C79.31 / C78.7 / C79.51 | Brain / liver / bone mets (MBC) |
Z85.3 | Personal hx breast malig (adjuvant) |
Z51.12 | Encounter for antineoplastic |
Payer requirements (May 2026)
| Payer | PA | HER2 / switch enforcement |
|---|
| UnitedHealthcare | Yes | Strict HER2 IHC 3+ or 2+/ISH+; new PA for SC switch; Optum site-of-care UM |
| Aetna | Yes | HER2 result + line of therapy + combo regimen + switch docs |
| BCBS plans | Yes | Aligned with NCCN + FDA label; some plans require IV trial first |
| Medicare Advantage | Plan-dep | FDA label-aligned; less aggressive than commercial |
Don't reuse the IV PA: Most payers require a new PA when switching from Perjeta+Herceptin IV to Phesgo SC. Submit with prior IV history + HER2 result + LVEF + clinical reason.
Medicare reimbursement (Q2 2026)
| Field | Value |
|---|
| ASP + 6% | $60.225 / 10 mg unit (Apr 1 – Jun 30, 2026) |
| 600 mg dose (maintenance) | $3,613.50 (60 × $60.225) |
| 1,200 mg dose (loading) | $7,227.00 (120 × $60.225) |
| Year-1 cost (loading + 16 maint) | ~$65,043 Phesgo drug only |
| Year-2+ steady (17 maint) | ~$61,430 Phesgo drug only |
Site of care
| Setting | POS | Notes |
|---|
| HOPD on/off-campus | 22 / 19 | Primary for loading dose (30-min obs); chemo coadmin encounters |
| Physician oncology office | 11 | Preferred for maintenance |
| Ambulatory infusion suite | 49 | Preferred; SC injection lane |
| Oncology ASC | 24 | Acceptable |
| Patient home | 12 | Uncommon — needs trained HCP + 15-30 min obs |
Patient assistance — Genentech Access
- Phone: 1-866-422-2377 (Genentech Access Solutions)
- Commercial copay: $0 OOP up to $25,000/year (excludes Medicare/Medicaid/federal)
- Patient Foundation: 1-888-941-3331 — free product, uninsured/underinsured (≤500% FPL)
- Medicare: PAN, HealthWell, CancerCare HER2+/oncology funds (verify quarterly)
- Web: genentech-access.com/hcp/brands/phesgo
LVEF MONITORING REQUIRED. Baseline echo (CPT 93306) or MUGA (CPT 78472) before initiation, then every 3 months during therapy. For early breast adjuvant: also q6 months for 24 months post-completion. Withhold for symptomatic LVEF decline or LVEF <40% (or 40–45% with ≥10pt drop from baseline). Boxed warnings: embryo-fetal toxicity + cardiomyopathy + pulmonary toxicity.