These three CPT codes describe the work of administering subcutaneous immune globulin (SCIG) via programmable infusion pump in a clinic, infusion suite, or hospital outpatient department. 96369 covers the initial infusion (up to 1 hour) plus pump set-up and establishment of the first SC site. 96370 covers each additional hour of infusion. 96371 covers each additional pump set-up at a new SC site — most adult SCIG doses require 2 to 4 simultaneous sites because per-site volume tolerance is limited. SCIG-formulated products (Hizentra, Cuvitru, Xembify, Cutaquig, HyQvia, Gamunex-C SC) use this code family; IVIG-formulated products administered IV use 96365 / 96366 instead.
CPT 96369 — “Subcutaneous infusion for therapy or prophylaxis (specify substance or drug); initial, up to 1 hour, including pump set-up and establishment of subcutaneous infusion site(s).” CPT 96370 — “Each additional hour (List separately in addition to code for primary procedure).” CPT 96371 — “Additional pump set-up with establishment of new subcutaneous infusion site(s) (List separately in addition to code for primary procedure).” All three are maintained by the American Medical Association in the CPT Professional Edition, Drug Administration subsection, under the therapeutic, prophylactic, and diagnostic injections and infusions heading.
The Medicare-side rules are codified in CMS Internet-Only Manual Publication 100-04 (Medicare Claims Processing Manual), Chapter 12 on physician drug administration services. Coverage criteria and frequency limits for SCIG specifically are published in each Medicare Administrative Contractor's Local Coverage Determination (LCD) and companion Local Coverage Article on immune globulin. The LCDs from Noridian, CGS, Palmetto, NGS, WPS, and First Coast are substantively aligned: they require documented primary immunodeficiency with antibody deficiency, prior IVIG failure or intolerance (or initial therapy for stable PI), and modifier KX on the J-code line attesting to medical necessity. Most LCDs cap 96371 at 2 units per encounter, mirroring a typical 3-site SCIG infusion.
The CPT additional-hour time-counting convention — a partial hour of 31 minutes or more counts as a unit of 96370; 30 minutes or less does not — mirrors the IV infusion convention used for 96366. Documentation of start and stop times for each SC site is required for audit support.
The structure of the code family reflects the structure of a real SCIG infusion: one pump, one initial site set-up bundled with up to an hour of infusion (96369), then additional hours of pumping (96370) and additional simultaneous sites that share the pump but each need their own needle set and skin prep (96371). The most common adult Hizentra or Cuvitru maintenance dose runs 2 sites over 90 to 120 minutes — coded as 96369 + 96370 + 96371. Pediatric and very-stable adult patients sometimes finish a single-site infusion under 60 minutes and code 96369 alone.
The two largest SCIG denial sources are (a) using 96365 for a true subcutaneous administration — the pump and the SC route make this a 96369 service, not 96365 — and (b) over-billing 96371. Document the number of simultaneous sites explicitly in the chart and align unit count with the LCD limit.
The Medicare MAC LCDs are the source of truth for SCIG administration coverage. Most commercial payers have aligned to the LCD framework, though biggest divergence is in (a) whether home SCIG is covered under the medical or pharmacy benefit and (b) the maximum 96371 units allowed per encounter.
| Payer | SCIG admin code family accepted? | Notes |
|---|---|---|
| Medicare (Part B) | Yes | IOM Pub 100-04, Ch. 12 governs. MAC LCDs (Noridian, CGS, Palmetto, NGS, WPS, First Coast) specify SCIG medical-necessity criteria, modifier KX requirement on the J-code line, and a 2-unit-per-encounter cap on 96371 in most jurisdictions. Verify the patient's MAC LCD before billing. |
| UnitedHealthcare | Yes | Aligns with CMS / MAC LCDs at adjudication. Commercial reimbursement policy on infusion administration explicitly references the CPT subcutaneous infusion family. OptumRx home-infusion management may steer home SCIG to a per-diem benefit; clinic SCIG bills under medical with 96369 / 96370 / 96371. |
| Aetna (CVS Health) | Yes | Aligns with CMS. Aetna clinical policy bulletin on immune globulin covers the SCIG product list and references the CPT code family for clinic administration. CVS Specialty handles outpatient SCIG dispensing; the practice bills the medical administration codes. |
| Cigna / Express Scripts | Yes | Aligns with CMS. Accredo specialty dispensing reports include suggested administration codes for SCIG products on the dispense sheet. Cigna applies a soft edit when 96371 units exceed 2 and may request the infusion record. |
| Humana | Yes | MA-heavy book follows CMS MAC LCDs. CenterWell Specialty handles home SCIG via the home infusion benefit (per-diem); clinic SCIG bills standard 96369 / 96370 / 96371. Humana commercial PPO has the same alignment with a slightly later edit-cycle enforcement than Medicare. |
| Denial pattern | What it means | Fix / appeal language |
|---|---|---|
| SCIG billed with 96365 (wrong route) | 96365 (initial IV infusion) was billed for a subcutaneous SCIG administration. The route does not match the code; the line is denied or down-coded. | Resubmit with 96369 (initial SCIG infusion) plus 96370 / 96371 as applicable. Appeal language: “The product administered, [SCIG product name, J-code], was administered via the subcutaneous route by programmable pump, not intravenously. The correct CPT for subcutaneous infusion of immune globulin is 96369 (initial, up to 1 hour, including pump set-up and SC site establishment), with 96370 and 96371 as additional-time and additional-site add-ons per CPT Drug Administration subsection.” |
| 96371 units exceed LCD limit (CARC 119 / N362) | More than 2 units of 96371 were billed in a single SCIG encounter, exceeding the MAC LCD cap. | If the encounter truly required more than 2 additional sites, the LCD may allow exception with clinical justification; otherwise resubmit with 96371 capped at the LCD limit. Appeal language: “Per [MAC name] LCD [number] on immune globulin, 96371 is limited to [N] units per SCIG encounter. The clinical justification for [N+1] simultaneous sites is documented in the chart at [reference]: [brief clinical reason — e.g., patient could not tolerate high per-site volume, required 4-site distribution]. Supporting documentation attached.” |
| 96370 or 96371 without primary 96369 (CARC 107 / N122) | An add-on code was submitted without its required primary procedure on the same claim. 96370 and 96371 cannot stand alone. | Resubmit with 96369 on the same claim. If the encounter genuinely was only a partial-hour, single-site infusion, the correct code is 96369 alone, not 96370 by itself. Appeal language: “96370 and 96371 are add-on codes per CPT and may only be reported in addition to a primary 96369 on the same claim. The corrected claim includes the primary 96369 that was inadvertently omitted from the original submission.” |
| SCIG site-of-care denial (home vs clinic) | Clinic SCIG admin codes (96369 / 96370 / 96371) were billed for an administration that the payer's records show was performed at home, where per-diem home-infusion codes apply. | Verify the actual site of service on the chart and the place-of-service code on the claim. If administration was truly in the clinic / infusion suite (POS 11 office, POS 22 hospital outpatient, POS 24 ASC, POS 19 hospital outpatient off-campus), provide the documentation. If administration was at home (POS 12), switch to the home-infusion per-diem benefit billing. Appeal language: “Place-of-service on this claim is [POS code], reflecting administration in the [office / outpatient infusion suite]. The CPT codes 96369 / 96370 / 96371 apply to subcutaneous infusion services in this setting per CPT and CMS IOM Pub 100-04 Ch. 12. Attached documentation includes the infusion record signed by the administering RN at [facility].” |
| Missing modifier KX on SCIG J-code line | The administration codes adjudicated but the J-code line was denied because KX was missing on the drug line, which most MAC LCDs require to attest to SCIG medical-necessity criteria. | Resubmit the J-code line with KX appended. Verify the chart documents the LCD-required clinical criteria (typically primary immunodeficiency with antibody deficiency, prior IVIG failure or intolerance or initial therapy for stable PI, and prescriber attestation). Appeal language: “The patient meets the LCD [number] medical-necessity criteria for SCIG, documented in the chart at [reference]. The corrected claim appends modifier KX to the [J-code] drug line per LCD requirement. Modifier KX is required on the drug line, not on the administration code lines (96369 / 96370 / 96371).” |
SCIG (subcutaneous immune globulin) is administered into the subcutaneous tissue via a programmable pump and is coded with CPT 96369 (initial, including pump set-up and site establishment, up to 1 hour), 96370 (each additional hour), and 96371 (additional pump set-up at a new SC site). IVIG (intravenous immune globulin) is administered intravenously and uses CPT 96365 (initial IV infusion up to 1 hour) and 96366 (each additional hour). Billing 96365 for a true SCIG administration is a top-three SCIG denial.
Most adult SCIG maintenance doses require 2 to 4 simultaneous subcutaneous infusion sites because per-site volume tolerance is limited. The first site set-up is included in 96369. Each additional site set-up is reported as 96371. Most Medicare Administrative Contractor (MAC) Local Coverage Determinations cap 96371 at 2 units per encounter, reflecting a typical 3-site SCIG infusion. Always check the current LCD for the patient's MAC before exceeding 2 units.
96370 is reported for each additional hour of SCIG infusion beyond the first hour included in 96369. The CPT time-counting convention requires that any additional hour increment must exceed 30 minutes to qualify; a partial hour of 31 minutes or more counts as a unit of 96370, while 30 minutes or less does not. Document infusion start and stop times in the chart for each site.
The 96369 / 96370 / 96371 family applies to all SCIG-formulated immune globulin products, including Hizentra (J1559), Cuvitru (J1555), Cutaquig (J1551), Xembify (J1558), HyQvia (J1575, recombinant hyaluronidase facilitated SC), and Gamunex-C when administered via the SC route (J1561). IVIG-formulated products administered IV remain on 96365 / 96366.
Home SCIG administered by a home infusion provider is typically billed under the home infusion therapy benefit using HCPCS S-codes or G-codes for the per-diem nursing and pump set-up, not CPT 96369 / 96370 / 96371. CPT 96369 / 96370 / 96371 apply when the SCIG infusion is administered in a physician office, outpatient infusion suite, or hospital outpatient department. Home self-administration training visits use separate codes (e.g., G0068 family). Confirm site-of-service before code selection.
For Medicare Part B, modifier KX is required on the SCIG drug J-code line when the prescriber attests in the chart that the patient meets the medical-necessity criteria documented in the MAC LCD for SCIG (typically primary immunodeficiency with documented antibody deficiency, with prior IVIG failure or intolerance, or as initial therapy for stable PI). KX is appended to the J-code line, not to the administration code lines (96369 / 96370 / 96371).
Yes. 96369 stands alone if the entire SCIG infusion was completed within 60 minutes. Most adult maintenance SCIG infusions run 60 to 120 minutes per site, so 96369 + 96370 ×1 (or ×2) is the typical pattern. Very low-volume pediatric infusions sometimes finish under 60 minutes and bill 96369 alone.
Yes. 96370 is an add-on code and must be reported in addition to 96369 on the same claim. 96370 cannot stand alone. Likewise, 96371 is an add-on that requires a primary 96369 on the same claim. Submitting 96370 or 96371 without 96369 will trigger a missing-primary-code denial.
All sources are publicly available federal publications, AMA-published code descriptors, FDA labeling, or paraphrased from trade-association educational materials. The methodology by which we resolve source disagreements is described in the Methodology.