Libtayo (J9119) Billing & Coding Guide | Cemiplimab-rwlc

Phase 1 Identify what you're billing Fixed 350 mg q3w dose simplifies units; biomarker only matters for NSCLC mono.

The cSCC / BCC dermatologic oncology niche FDA verified May 2026

Libtayo's distinct identity: the first — and most established — checkpoint inhibitor for advanced skin cancers other than melanoma.

September 28, 2018: Libtayo (cemiplimab-rwlc) became the first drug ever FDA-approved for locally advanced or metastatic cutaneous squamous cell carcinoma — opening systemic immunotherapy as a treatment option for a population previously limited to surgery, radiation, or platinum chemotherapy. The advanced BCC indication followed in 2021 (post-Hedgehog pathway inhibitor failure or intolerance). These dermatologic skin cancer indications remain Libtayo's highest-volume oncology niche.

Why dermatologic oncology billing volume matters

Advanced cSCC and BCC patients tend to be elderly with significant sun exposure histories, immunosuppression (transplant recipients), and multiple comorbidities that often contraindicate aggressive surgery or re-irradiation. Practices in dermatology, dermatologic oncology, head and neck surgery, and Mohs-affiliated groups bill J9119 at meaningful volume. Many of these patients are on Medicare and require careful ASP-driven reimbursement modeling and Medigap planning.

cSCC clinical pathway (NCCN-aligned)

Surgery (Mohs / wide excision) is first-line for resectable disease
Radiation therapy second-line or for non-surgical candidates
Libtayo systemic therapy for locally advanced or metastatic disease not curable by surgery or radiation
Standard dose: 350 mg IV q3w until disease progression or unacceptable toxicity

BCC clinical pathway

Hedgehog pathway inhibitor (vismodegib, sonidegib) first-line for advanced/metastatic BCC
Libtayo for HPI failure or HPI intolerance — this is the labeled second-line
Standard dose: 350 mg IV q3w

Dosing by indication FDA label verified May 2026

From FDA prescribing information, label revised 2025 with cervical cancer addition (BLA 761097).

Indication	Dose	Schedule	Combo agent	Biomarker
Advanced cSCC (locally advanced or metastatic, not surgically/RT curable)	350 mg IV	q3 weeks	Monotherapy	Not required
Advanced BCC (locally advanced or metastatic, post-HPI)	350 mg IV	q3 weeks	Monotherapy (after vismodegib/sonidegib failure or intolerance)	Not required
NSCLC 1L monotherapy	350 mg IV	q3 weeks	Monotherapy	PD-L1 ≥50% required (22C3 or SP263); no EGFR/ALK/ROS1 alterations
NSCLC 1L + platinum chemo	350 mg IV	q3 weeks	+ Platinum-based chemotherapy (any histology)	Any PD-L1 (no testing requirement)
Cervical cancer (recurrent/metastatic, post-platinum) 2025	350 mg IV	q3 weeks	Monotherapy	Not required

Single fixed dose simplifies billing. Unlike Opdivo (240 mg q2w or 480 mg q4w) or Keytruda (200 mg q3w or 400 mg q6w), Libtayo uses one dose — 350 mg every 3 weeks — across every approved indication. One vial. 350 units. q3w cadence. The unit math is the same whether you're billing for a 75-year-old advanced cSCC patient or a 1L NSCLC patient with high PD-L1 expression.

Worked example — first-year billing for an advanced cSCC patient (350 mg q3w)

# 17 doses (q3w) per 52-week year Drug units billed per dose: 350 (J9119) HCPCS: J9119 \cdot Modifier: JZ \cdot Vials: 1 \times 350 mg Admin: 96413 (30-min chemo IV) # Year-1 totals Total doses: 17 Total drug units billed: 5,950 (17 \times 350) Total drug cost (Q2 2026 ASP+6%): ~$177,084 before sequestration

No premedication routinely required

Like other anti-PD-1 agents (Keytruda, Opdivo, Jemperli), Libtayo does NOT require pre-infusion methylprednisolone or antihistamine. Manage infusion reactions per FDA label if they occur.

NDC reference FDA NDC Directory verified May 2026

NDC (10/11-digit)	Package	Use
`61755-008-01` / `61755-0008-01`	350 mg / 7 mL (50 mg/mL) single-dose vial — 1 vial per carton	Standard 350 mg fixed dose — one carton per dose, no waste

Use carton-level NDC on the claim form. Vial-level NDC will trigger denial. The 1:1 mapping between vial size (350 mg) and dose (350 mg) means every adult Libtayo claim should bill exactly one vial worth of NDC + 350 J9119 units + JZ.

Checkpoint class comparison Verified May 2026

Libtayo (J9119) sits alongside the established anti-PD-1 / anti-PD-L1 immunotherapy class. Each has different HCPCS, dosing, and indication footprint.

Drug	HCPCS	Class	Dosing	Distinct niche
Libtayo (cemiplimab-rwlc)	`J9119`	Anti-PD-1	350 mg q3w fixed	cSCC, BCC (dermatologic oncology); NSCLC; cervical
Keytruda (pembrolizumab)	`J9271`	Anti-PD-1	200 mg q3w or 400 mg q6w fixed	Broadest indication footprint (20+); melanoma + NSCLC anchor
Opdivo (nivolumab)	`J9299`	Anti-PD-1	240 mg q2w or 480 mg q4w fixed; pediatric weight-based	15+ indications; pediatric cHL/MSI-H/dMMR; SC Qvantig sister product
Tecentriq (atezolizumab)	`J9022`	Anti-PD-L1	1200 mg q3w or 1680 mg q4w fixed	NSCLC, SCLC, HCC, TNBC, urothelial, melanoma
Imfinzi (durvalumab)	`J9173`	Anti-PD-L1	10 mg/kg q2w or 1500 mg q4w	NSCLC consolidation post-CRT (PACIFIC); ES-SCLC; biliary tract; HCC
Jemperli (dostarlimab-gxly)	`J9272`	Anti-PD-1	500 mg q3w → 1000 mg q6w	Endometrial (dMMR, MSI-H); 1L primary advanced/recurrent endometrial + chemo

NSCLC indication overlap. Libtayo, Keytruda, Opdivo, Tecentriq, and Imfinzi all have NSCLC label entries with overlapping but not identical biomarker thresholds and combo regimens. Keytruda is the most commonly chosen 1L NSCLC mono in PD-L1 high tumors due to early entrenchment and broader physician familiarity; Libtayo is FDA-approved with the same PD-L1 ≥50% threshold. Payer formulary preferences often dictate which is used.

cSCC/BCC differentiation. Among the checkpoint class, only Libtayo has labeled approvals for both advanced cSCC and advanced BCC. Keytruda has cSCC under a similar advanced/metastatic indication but BCC remains Libtayo-distinctive.

Phase 2 Code the claim Chemotherapy admin codes apply (despite immunotherapy classification clinically).

Administration codes CPT verified May 2026

Cemiplimab is billed as chemotherapy administration despite being immunotherapy.

Code	Description	When to use
`96413`	Chemotherapy administration, IV infusion technique; up to 1 hour, single or initial substance/drug	Primary code for Libtayo IV. 30-min standard infusion fits within 1-hour window.
`96415`	Chemotherapy administration, IV infusion; each additional hour	Pair with 96413 for NSCLC + chemo combo regimens that extend chair time beyond 1 hour with platinum + pemetrexed/paclitaxel.
`96365` / `96366`	Therapeutic IV infusion (non-chemo)	NOT appropriate. CPT classifies cemiplimab admin under chemo codes per AMA guidelines for monoclonal antibody immunotherapy.

Why chemo admin for immunotherapy: CPT chemotherapy administration codes (96409–96425) apply to complex monoclonal antibody administration regardless of mechanism of action. Cemiplimab and other immune checkpoint inhibitors are billed under chemo admin codes per AMA classification. This pays materially more than 96365 therapeutic infusion.

Modifiers CMS verified May 2026

JZ — required on virtually every Libtayo claim

Effective July 1, 2023, CMS requires the JZ modifier on all single-dose container claims when no drug is discarded. Libtayo's 350 mg fixed dose matches the 350 mg single-dose vial exactly — JZ applies to virtually every adult Libtayo claim.

JW — rare for Libtayo (no routine waste)

JW reports the discarded portion of a single-dose vial. Because Libtayo's dose-to-vial mapping is 1:1, JW only applies in rare scenarios such as dose reduction during toxicity management when a partial vial is used and the remainder discarded. One of JZ or JW must be on every J9119 claim.

Modifier 25 — same-day E/M

Use modifier 25 on the E/M code when a significant, separately identifiable evaluation and management service is performed on the same day as the infusion (e.g., toxicity evaluation, decision-making about irAE management). Routine pre-infusion clinical assessment is bundled.

340B modifiers (JG, TB)

For 340B-acquired Libtayo, follow your MAC's current 340B modifier policy. Regeneron's billing guide does not provide 340B-specific instructions.

ICD-10-CM by indication group FY2026 verified May 2026

Multi-indication matrix. Use the most specific code supported by encounter documentation.

Cutaneous SCC (cSCC) — by site (most common)

ICD-10 family	Site	Notes
`C44.42x`	SCC of skin of scalp and neck	Common in elderly sun-exposed patients
`C44.4x`	SCC of skin of face (ear, eyelid, nose, lip, etc.)	Most common cSCC site; periauricular high-risk
`C44.5x`	SCC of skin of trunk	Includes anal margin, breast, perianal
`C44.6x`	SCC of skin of upper limb (incl. shoulder)
`C44.7x`	SCC of skin of lower limb (incl. hip)
`C44.8x` / `C44.9x`	SCC of overlapping sites / unspecified	Use only when site cannot be specified
`C77.x`	Secondary lymph node involvement (metastatic cSCC)	Pair with primary site code
`C78.x` / `C79.x`	Distant metastases (lung, liver, bone, other)	For metastatic cSCC documentation

Basal cell carcinoma (BCC) — by site

ICD-10 family	Site	Notes
`C44.x1` family (4th char varies by site)	BCC of skin (specific site ×1 = BCC histology)	For site-specific BCC, use C44._1 codes (e.g., C44.41 face BCC)
`C44.41`	BCC of skin of face	Most common BCC site
`C44.51`	BCC of skin of trunk
`C44.61`	BCC of skin of upper limb
`C44.71`	BCC of skin of lower limb
`C44.91`	BCC of skin, unspecified

NSCLC and cervical

Indication	ICD-10 family	Notes
NSCLC (1L mono, PD-L1 ≥50%)	`C34.x`	Histology-specific 4th character; PD-L1 testing required for mono
NSCLC (1L + platinum chemo)	`C34.x`	Any PD-L1 / any histology; no testing required
Cervical cancer (recurrent/metastatic, post-platinum)	`C53.x`	Added to label in 2025

Indication-specific PA criteria are the norm. Most payers require ICD-10 code, prior therapies, line of therapy, AND for some indications biomarker results / specialty consultation documentation. The ICD-10 code alone is not sufficient for approval. For cSCC, document why surgery and radiation are not curative options. For BCC, document HPI failure or intolerance.

Site of care & place of service Verified May 2026

UnitedHealthcare, Aetna, and most major BCBS plans run aggressive site-of-care UM for immune checkpoint inhibitors. Aetna CPB 0892 explicitly steers ICIs out of HOPD after the first 3 months unless on combo chemo or active toxicity management.

Setting	POS	Claim form	Payer steering
Physician oncology / dermatology office	11	CMS-1500 / 837P	Preferred by commercial UM
Ambulatory infusion suite (AIC)	49	CMS-1500 / 837P	Preferred by commercial UM
Oncology ASC	24	CMS-1500 / 837P	Acceptable
Hospital outpatient (on-campus)	22	UB-04 / 837I	Disfavored after first 3 months
Hospital outpatient (off-campus PBD)	19	UB-04 / 837I	Disfavored after first 3 months
Patient home	12	CMS-1500 (with home infusion)	Possible but rare for IV oncology IO

Dermatology office consideration: Some dermatologic oncology practices and Mohs-affiliated groups infuse Libtayo for advanced cSCC/BCC patients at POS 11. Confirm administration capability and oncology billing competence before billing under a non-medical-oncology specialty NPI — some payers route ICI claims through medical oncology benefit logic.

Claim form field mapping Regeneron 2025

From Regeneron Libtayo Surround coding & coverage guide.

Information	CMS-1500 box	Notes
NPI	17b	Rendering provider
NDC qualifier + 11-digit NDC + UoM + qty	24A shaded area	N4 + carton NDC `61755-0008-01` + ML + 7 mL
HCPCS J9119 + JZ (or JW for waste)	24D (drug line)	JZ on virtually every claim
Drug units	24G	350 (matches 350 mg fixed dose)
CPT 96413 (admin line)	24D (admin line)	30-min infusion fits within 1-hour window
ICD-10	21	Indication-specific (see ICD-10 tables)
PD-L1 IHC test claim line (NSCLC mono only)	24D	CPT 88360 (manual) or 88361 (computer-assisted)
PA number	23	Required by all major payers

Phase 3 Get paid PD-L1 only matters for NSCLC mono. cSCC/BCC PA hinges on surgical/radiation/HPI documentation.

Payer policy snapshot + biomarker Reviewed May 2026

PD-L1 only enforced for NSCLC 1L monotherapy. cSCC/BCC PA hinges on documenting why prior modalities are unavailable.

Payer	PA?	Biomarker / specialty enforcement	Site-of-care UM
UnitedHealthcare Oncology Med Coverage Policy	Yes	PD-L1 strict for NSCLC 1L mono; cSCC requires documentation that surgery/RT non-curable; BCC requires HPI failure or intolerance	Aggressive: ICI steering away from HOPD via Optum-managed program
Aetna CPB 0892 + Medical Drug	Yes	PD-L1 required for NSCLC mono; HPI failure docs for BCC; specialty consult for cSCC	Yes (separate Site-of-Care policy; ICIs steered out of HOPD after 3 months)
BCBS plans Vary by plan	Yes	Generally aligned with NCCN cSCC, BCC, NSCLC, and Cervical guidelines + FDA label biomarker	Plan-specific; most have ICI site-of-care steering

Biomarker test billing (NSCLC 1L mono only)

Test	CPT	For Libtayo indication
PD-L1 IHC (22C3 pharmDx or SP263)	`88360` (manual) / `88361` (computer-assisted)	NSCLC 1L monotherapy — PD-L1 TPS ≥50% required
EGFR / ALK / ROS1 (negative documentation)	Variable NGS panel codes (e.g., `81445`, `81455`)	Required to rule out targetable alterations before NSCLC mono

cSCC and BCC PA documentation: surgical/radiation rationale, not biomarker. For advanced cSCC, payers expect documentation that the patient is not a candidate for curative surgery (e.g., size, location, multifocal, prior failed surgical attempts) and not a candidate for curative radiation (prior irradiation, location adjacent to critical structures, patient comorbidities). For advanced BCC, payers expect documentation of Hedgehog pathway inhibitor failure (vismodegib or sonidegib) or intolerance.

Step therapy

Generally NOT required for FDA-labeled 1L cSCC indication. For BCC, HPI is the labeled prerequisite. For NSCLC, line of therapy and biomarker drive policy. For cervical, prior platinum is a labeled prerequisite. Verify per-payer.

Medicare reimbursement CMS Q2 2026 (live)

Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.

Q2 2026 payment snapshot — J9119

Effective April 1 – June 30, 2026 · Based on 4Q25 ASP submissions

ASP + 6%

$29.762

per mg / per unit

350 mg dose (q3w)

$10,416.70

350 units × ASP+6%

Annualized (~17 doses)

~$177,084

Year-1 Medicare ASP+6%

Annualized cost: 350 mg q3w × ~17 doses (52-week year) = ~$177,084/year (Medicare ASP+6%). After ~2% sequestration: ~$172,000/year actual paid.

Coverage

No NCD specific to cemiplimab. Coverage falls under MAC LCDs for biologics + the generic drug-coverage framework. All MACs cover J9119 for FDA-approved on-label indications with appropriate ICD-10 and biomarker (where applicable) documentation.

Code history

J9119 — permanent code, "Injection, cemiplimab-rwlc, 1 mg" (initial FDA approval was September 28, 2018; pre-permanent-code period used unclassified J9999/J3490)

Patient assistance — Libtayo Surround Support Regeneron verified May 2026

Libtayo Surround Support: 1-877-542-2826 — benefits investigation, prior authorization assistance, appeal support, copay program enrollment
Libtayo Co-Pay Program: commercial copay support; eligible commercially-insured patients — $0 first dose + ongoing reduced-copay support (excludes Medicare, Medicaid, and other federal program patients)
Regeneron Patient Foundation: free product for uninsured / underinsured patients meeting income and clinical eligibility criteria (independent 501(c)(3) foundation)
Foundations for Medicare patients: refer to PAN, HealthWell, CancerCare for oncology disease-specific funds — verify open funds quarterly (cSCC, BCC, NSCLC, cervical fund availability rotates)
Web: libtayohcp.com

Need to model what a specific patient will actually pay after copay assistance, deductible, coinsurance, and OOP max? Run a CareCost Estimate — J9119 pre-loaded.

Phase 4 Fix problems irAE management drives the most clinical interrupts; biomarker documentation drives the most denials.

Immune-mediated adverse reactions (irAEs) FDA W&P Apr 2026

Same checkpoint class irAE profile as Keytruda, Opdivo, Tecentriq, Imfinzi, and Jemperli. Coding for management is a meaningful billing volume driver.

SEVERE / FATAL IMMUNE-MEDIATED ADVERSE REACTIONS — treat as Boxed analog. Cemiplimab is a PD-1 blocker and shares the class W&P profile of severe and potentially fatal immune-mediated adverse reactions affecting any organ system. Monitor and manage according to FDA label. Withhold or permanently discontinue based on severity. Administer corticosteroids 1–2 mg/kg/day prednisone equivalent for grade 2+ events. Consider higher-dose IV methylprednisolone for life-threatening events. Hormone replacement for endocrinopathies as clinically indicated.

Common irAEs (per FDA label and class data)

Pneumonitis — including fatal cases. Hold for grade 2; permanently discontinue grade 3+.
Colitis — presents as diarrhea, abdominal pain, bloody stool. Hold and steroid for grade 2+.
Hepatitis — transaminitis with or without symptoms. Hold for grade 2; discontinue grade 3+.
Endocrinopathies — hypothyroidism (most common), thyroiditis → hyperthyroidism, T1DM, adrenal insufficiency, hypophysitis. Hormone replacement; ICI may continue at clinician discretion for stable hypothyroidism on replacement.
Nephritis with renal dysfunction — rising creatinine. Hold for grade 2.
Severe dermatologic reactions — SJS, TEN, DRESS. Permanently discontinue.
Infusion-related reactions — manage per institutional protocol; pre-medicate for subsequent infusions if mild-moderate reaction.

Billing implications of irAE management

Office E/M visits for irAE evaluation: bill with modifier 25 if same-day infusion
Hospital admission for severe irAE: separate inpatient billing; specialist consults (endocrine, GI, pulm, derm, nephro) bill independently
Hormone replacement ongoing: levothyroxine, hydrocortisone, etc. — pharmacy benefit, not J9119
Diagnostic workup: CT (pneumonitis), endoscopy (colitis), TSH/free T4/cortisol/ACTH (endocrinopathies), UA/creatinine (nephritis), skin biopsy (dermatologic) — all billed independently

Common denials & how to fix them

Denial reason	Common cause	Fix
Surgery/RT contraindication not documented (cSCC)	PA submitted without rationale for systemic therapy over surgery or radiation	Submit clinical narrative documenting tumor size/location, prior failed local therapy, comorbidities, and patient ineligibility for curative local treatment.
HPI failure not documented (BCC)	BCC PA submitted without prior vismodegib or sonidegib documentation	Submit prior HPI Rx history, response, and reason for discontinuation (failure or intolerance).
PD-L1 not documented (NSCLC mono)	NSCLC monotherapy PA submitted without PD-L1 result	Submit PD-L1 IHC TPS ≥50% (22C3 or SP263) + EGFR/ALK/ROS1 negative documentation. Consider switching to NSCLC + chemo regimen if biomarker doesn't qualify.
Wrong admin code (96365)	Therapeutic IV billed instead of chemo IV	Resubmit with 96413. Cemiplimab is chemo admin per CPT classification despite being immunotherapy.
JZ missing on adult claim	Single-dose vial claim without JZ	Resubmit with JZ. Required since 7/1/2023 on every claim with no waste.
Wrong NDC format (vial-level)	Vial NDC submitted instead of carton NDC	Use carton NDC: `61755-0008-01`.
Site of care (HOPD)	HOPD administration after first 3 months on commercial plan with site-of-care UM	Move to office (POS 11) or AIC (POS 49). Submit medical necessity letter if HOPD required.
Indication-specific PA criteria not met	ICD-10 alone insufficient; line of therapy or combo regimen not documented	Submit complete clinical history including prior therapies, response, and current line of therapy.

Frequently asked questions

What is the HCPCS code for Libtayo?

Libtayo (cemiplimab-rwlc) is billed under HCPCS J9119 — "Injection, cemiplimab-rwlc, 1 mg." Each milligram equals one billable unit. The standard 350 mg every 3 weeks fixed dose is billed as 350 units. Same dose applies across all FDA-approved indications: cutaneous SCC, basal cell carcinoma, NSCLC (mono and combo with chemo), and cervical cancer.

How many units do I bill for a Libtayo dose?

Bill 350 units of J9119 per dose. Libtayo uses fixed-dose administration of 350 mg IV every 3 weeks for all approved indications — not weight-based. The 350 mg / 7 mL single-dose vial matches the dose exactly, so one vial per administration with no waste.

What administration CPT do I use for Libtayo?

CPT 96413 — "Chemotherapy administration, IV infusion technique; up to 1 hour, single or initial substance/drug." Despite being immunotherapy, Libtayo is classified for billing purposes as a chemotherapy administration drug because it is a complex monoclonal antibody (anti-PD-1). Standard infusion is 30 minutes, fitting within the 1-hour 96413 window. Add 96415 (each additional hour) only if combo regimens extend chair time. Do NOT bill 96365.

Do I bill JZ or JW for Libtayo?

Bill JZ on virtually every Libtayo claim. The 350 mg fixed dose matches the 350 mg single-dose vial exactly, so there is no waste. JW only applies in rare scenarios where dose reduction or partial vial use occurs. One of JZ or JW must be on every J9119 claim per CMS's July 2023 single-dose container policy.

What is the Medicare reimbursement for J9119?

For Q2 2026, the Medicare Part B payment limit for J9119 is $29.762 per mg (ASP + 6%). The standard 350 mg q3w dose reimburses at approximately $10,416.70 per infusion. Annualized cost (Medicare ASP+6%): approximately $177,000 per year for ~17 doses (q3w schedule × 52 weeks). Sequestration (~2%) reduces actual paid to roughly ASP + 4.3%.

What are Libtayo's FDA-approved indications?

Libtayo is approved for: (1) locally advanced or metastatic cutaneous squamous cell carcinoma (cSCC) not curable by surgery or radiation — Libtayo was the FIRST drug FDA-approved for advanced cSCC in 2018; (2) locally advanced or metastatic basal cell carcinoma (BCC) after Hedgehog pathway inhibitor (HPI) failure or intolerance; (3) NSCLC 1L monotherapy in PD-L1 ≥50% tumors without EGFR/ALK/ROS1 alterations; (4) NSCLC 1L combination with platinum-based chemotherapy regardless of PD-L1 or histology; (5) recurrent or metastatic cervical cancer after platinum-based therapy (added 2025).

Does Libtayo require biomarker testing for prior auth?

Yes for NSCLC 1L monotherapy. PD-L1 expression ≥50% by IHC (22C3 pharmDx or SP263) is required, plus documentation that EGFR, ALK, and ROS1 are NOT altered. PD-L1 testing is NOT required for NSCLC 1L combination with chemotherapy (any PD-L1, any histology). PD-L1 testing is also NOT required for cSCC, BCC, or cervical indications. Bill PD-L1 IHC separately under CPT 88360 (manual) or 88361 (computer-assisted).

How does Libtayo compare to other checkpoint inhibitors?

Libtayo (J9119, anti-PD-1, 350 mg q3w fixed) competes directly with Keytruda (J9271, anti-PD-1, 200 mg q3w or 400 mg q6w fixed), Opdivo (J9299, anti-PD-1, 240 mg q2w or 480 mg q4w fixed plus weight-based), Tecentriq (J9022, anti-PD-L1), Imfinzi (J9173, anti-PD-L1), and Jemperli (J9272, anti-PD-1). Libtayo's distinct niche is dermatologic oncology — it was the first FDA-approved drug for advanced cSCC and remains a primary option for advanced BCC after HPI failure. NSCLC label overlaps significantly with Keytruda.

Reference Sources & methodology Every claim on this page is sourced. Methodology and review history below.

Source documents

Regeneron — Libtayo HCP Site (libtayohcp.com)
Manufacturer-published HCP coding, coverage, and reimbursement resources
DailyMed — LIBTAYO (cemiplimab-rwlc) Prescribing Information
FDA-approved label, most recently revised 2025 (cervical cancer addition); BLA 761097
FDA Libtayo label PDF
FDA Drugs@FDA label archive; most recent revision incorporates 2025 cervical approval
Regeneron press releases — FDA approvals (2018 cSCC, 2021 NSCLC + BCC, 2025 cervical)
CMS — Medicare Part B Drug ASP Pricing File
Q2 2026 quarterly file, effective April 1 – June 30, 2026
SEER CanMED — HCPCS J9119 reference
UnitedHealthcare — Oncology Medication Clinical Coverage Policy
Aetna CPB 0892 — Immune Checkpoint Inhibitors
NCCN Guidelines — Squamous Cell Skin Cancer, Basal Cell Skin Cancer, NSCLC, Cervical Cancer
FDA National Drug Code Directory

About this page

We maintain this page as a living reference. Medicare ASP pricing is bound to our underlying CareCost data layer and refreshes automatically when CMS publishes new quarterly files. Coding and policy content is reviewed at least quarterly and updated whenever a source document changes.

Found an error? Email hello@carecostestimate.com.

Refresh cadence

Element	Cadence	How it's refreshed
Medicare ASP pricing	Quarterly	Auto-bound to CareCost ASP layer; updates on CMS file release.
Payer policies (UHC, Aetna, BCBS)	Semi-annual	Manual review against published payer policy documents.
HCPCS / CPT / modifier rules + biomarker test codes	Annual	Reviewed against CMS HCPCS quarterly files, AMA CPT releases, and AMA Category III code updates.
NDC, dosing, FDA label, indication list	Event-driven	Tied to FDA label revision date. Libtayo gains new indications periodically (2018 cSCC → 2021 NSCLC + BCC → 2025 cervical).

Reviewer

Pending SME review. This page is staff-authored from primary sources (FDA, CMS, manufacturer, payer documents — all linked above). Editorial review in progress. Until that review is complete, treat this as a draft reference and verify each cited source for high-stakes claims.

Change log

May 2, 2026 — Initial publication. ASP data: Q2 2026 ($29.762/mg). Manufacturer source: Regeneron Libtayo Surround 2025. FDA label: most recent revision incorporating 2025 cervical cancer addition (BLA 761097). Five FDA-approved indications: advanced cSCC (2018), advanced BCC (2021), NSCLC 1L mono PD-L1 ≥50% (2021), NSCLC 1L + chemo (2022), cervical cancer post-platinum (2025).

Methodology

Every claim on this page is sourced inline. Pricing reflects the current CMS Part B Drug ASP Pricing File. Payer policies are read directly from each payer's published medical/pharmacy policy documents. Indication list is verified against the current FDA label revision. We do not paraphrase from billing-software vendor blogs.

Libtayo (cemiplimab-rwlc) — HCPCS J9119

Instant Answer — the 5 things you need to bill J9119

The cSCC / BCC dermatologic oncology niche FDA verified May 2026

Why dermatologic oncology billing volume matters

cSCC clinical pathway (NCCN-aligned)

BCC clinical pathway

Dosing by indication FDA label verified May 2026

Worked example — first-year billing for an advanced cSCC patient (350 mg q3w)

No premedication routinely required

NDC reference FDA NDC Directory verified May 2026

Checkpoint class comparison Verified May 2026

Administration codes CPT verified May 2026

Modifiers CMS verified May 2026

JZ — required on virtually every Libtayo claim

JW — rare for Libtayo (no routine waste)

Modifier 25 — same-day E/M

340B modifiers (JG, TB)

ICD-10-CM by indication group FY2026 verified May 2026

Cutaneous SCC (cSCC) — by site (most common)

Basal cell carcinoma (BCC) — by site

NSCLC and cervical

Site of care & place of service Verified May 2026

Claim form field mapping Regeneron 2025

Payer policy snapshot + biomarker Reviewed May 2026

Biomarker test billing (NSCLC 1L mono only)

Step therapy

Medicare reimbursement CMS Q2 2026 (live)

Q2 2026 payment snapshot — J9119

Coverage

Code history

Patient assistance — Libtayo Surround Support Regeneron verified May 2026

Immune-mediated adverse reactions (irAEs) FDA W&P Apr 2026

Common irAEs (per FDA label and class data)

Billing implications of irAE management

Common denials & how to fix them

Frequently asked questions

What is the HCPCS code for Libtayo?

How many units do I bill for a Libtayo dose?

What administration CPT do I use for Libtayo?

Do I bill JZ or JW for Libtayo?

What is the Medicare reimbursement for J9119?

What are Libtayo's FDA-approved indications?

Does Libtayo require biomarker testing for prior auth?

How does Libtayo compare to other checkpoint inhibitors?

Source documents

About this page

Refresh cadence

Reviewer

Change log

Methodology

Stop calculating Libtayo copays by hand.