JG attests that a separately payable Medicare Part B drug billed by a hospital outpatient department was acquired under the 340B Drug Pricing Program. It applies to 340B-covered entities that are subject to OPPS payment policy — most commonly Disproportionate Share Hospitals (DSH) and other non-exempt covered entities. The carved-out 340B categories (Rural Sole Community Hospitals, PPS-exempt Cancer Hospitals, Children's Hospitals) use the parallel TB modifier instead. JG drove a payment cut from 2018-2022; it no longer affects the rate (CY 2023 onward), but it remains a required identifier on every 340B-acquired Medicare OPPS drug claim line.
JG was introduced as a Medicare claim-identification mechanism in the Calendar Year 2018 OPPS Final Rule (CMS-1678-FC), which implemented the policy of paying separately payable 340B-acquired drugs at Average Sales Price (ASP) minus 22.5 percent rather than the default ASP plus 6 percent. The statutory hook was the OPPS authority to set drug payment rates under Section 1833(t) of the Social Security Act; CMS interpreted that authority to encompass paying differently for drugs based on acquisition cost. JG was the data carrier that let MACs identify which claim lines were subject to the lower rate.
The CY 2018 policy was challenged immediately. In American Hospital Association v. Becerra (June 2022, 596 U.S. ___), the Supreme Court ruled unanimously that CMS had exceeded its statutory authority because it had not conducted the drug acquisition-cost survey required as a prerequisite to varying rates by hospital group. CMS reverted to the default ASP plus 6 percent for both 340B and non-340B drugs in the mid-year CY 2022 update and codified the reversion in the CY 2023 OPPS Final Rule (CMS-1772-FC). The CY 2024 OPPS Remedy Rule (CMS-1793-F) directed a one-time lump-sum remedy payment to affected 340B hospitals for the 2018-2022 underpayment, funded by a budget-neutral OPPS conversion-factor reduction phased in over roughly 16 years starting CY 2026.
JG survived the policy reversal because CMS continues to use the identifier for monitoring, program-integrity, and ongoing rate analysis. Appending JG today does not change the payment amount, but omitting it from a 340B-acquired drug claim is a data-integrity violation that surfaces in both HRSA 340B program audits and Medicare program-integrity reviews.
The most common scenario for JG is a DSH hospital outpatient department administering a separately payable oncology biologic — Keytruda (J9271), Avastin (J9035), Rituxan (J9312) and its biosimilars, Herceptin (J9355), Opdivo (J9299), and similar drugs. These all run through 340B at large urban DSH facilities, and the JG attestation feeds both the Medicare claim and the 340B program-compliance audit trail. JG does not apply to drugs administered in inpatient settings (those are bundled into the DRG), to retail pharmacy claims under Part D (different program, different modifier), or to drugs that were not separately payable under OPPS in the first place.
The single highest-risk misuse is appending JG to drugs that were billed but not actually 340B-acquired — usually a virtual-replenishment bucket-reconciliation failure. This is treated as a false attestation under the False Claims Act because JG is a statement to Medicare about the drug's acquisition source. Run a quarterly reconciliation between 340B purchase records (from the wholesaler) and JG-tagged claims; investigate any variance over 1-2 percent.
JG is a Medicare claim-identification modifier. Traditional Medicare requires it on all 340B-acquired separately payable OPPS drug claims; commercial payers generally do not. Medicare Advantage plan policies vary — some require JG for parity with Traditional Medicare, some do not, and a few have used JG data to negotiate lower contracted rates. Always confirm plan-by-plan.
| Payer | JG required on 340B drug? | Notes |
|---|---|---|
| Medicare (Part B / OPPS) | Yes — required identifier | Source-of-truth payer. Required on every 340B-acquired separately payable drug for OPPS hospital outpatient encounters. Does not currently change payment rate (rate reverted to ASP+6 percent in CY 2023 per CMS-1772-FC) but remains required for program integrity and 340B audit trail. Inpatient drugs are bundled into the DRG and JG does not apply. |
| Medicare Advantage | Conditional | Plan-by-plan policy. Most major MA plans follow CMS conventions and accept JG; some require it. A small number of MA plans use 340B identification to negotiate lower contracted rates for 340B-acquired drugs, which is a separate commercial-contract dispute. Default to appending JG on MA claims unless the plan policy explicitly says otherwise. |
| UnitedHealthcare (commercial) | Generally no | Commercial UHC does not require JG. Some UHC contracts with 340B hospitals include separate 340B-identification or transparency provisions handled outside the HCPCS modifier set. UHC's Medicare Advantage book follows Medicare convention; check policy by line of business. |
| Aetna (CVS Health), commercial | Generally no | Commercial Aetna does not require JG. Aetna Medicare Advantage follows CMS convention. Aetna has not adopted a contract-level 340B reimbursement schedule as aggressively as some competitors but check plan-specific policy. |
| Cigna / Express Scripts (commercial) | Generally no | Commercial Cigna does not require JG on medical drug claims. Cigna has historically been the most active commercial payer in pursuing 340B-specific reimbursement renegotiations through contract, separate from HCPCS modifier requirements. |
| State Medicaid (varies) | Varies | Many state Medicaid programs require their own 340B identifier (often the UD modifier, not JG) for the Medicaid Drug Rebate Program duplicate-discount carve-out. The exact modifier and the carve-in vs carve-out policy vary by state. Confirm with the state Medicaid drug-billing manual; do not assume JG works for Medicaid. |
| Issue pattern | What it means | Fix / corrective action |
|---|---|---|
| JG omitted on 340B-acquired drug | Claim line for a separately payable Part B drug at a 340B covered entity did not carry JG. Not a denial in the strict CARC sense post-CY 2023 (payment is the same with or without JG), but a data-integrity gap that surfaces in HRSA 340B audits and CMS program-integrity reviews. During 2018-2022 this caused the hospital to receive the higher (ASP+6 percent) rate when the lower (ASP-22.5 percent) rate should have applied — an audit finding even though the hospital was paid more. | Submit a corrected claim with JG appended. Reconcile the 340B purchase records against the JG-tagged claims for the affected period quarterly. Adopt a hard-stop edit in the billing system that flags any line for a 340B-eligible drug at a 340B-registered site that drops without JG. |
| JG used when TB was correct (or vice versa) | JG appended at a Rural SCH, PPS-exempt cancer hospital, or Children's Hospital (which should use TB), or TB appended at a DSH (which should use JG). No payment-rate effect today; pre-2023, the misuse changed payment. | Verify the entity sub-category against the HRSA OPAIS record and the OPPS payment methodology applicable to the specific billing site. Submit a corrected claim with the correct modifier. Update the billing system's site-to-modifier mapping table; this is usually a one-time configuration error that affects an entire claim stream until fixed. |
| JG appended by a non-340B entity | JG attested on a claim from a billing entity that is not registered in the HRSA OPAIS database as a 340B covered entity. This is a false attestation to Medicare and creates direct False Claims Act exposure regardless of payment effect. | Cease appending JG immediately. Audit historical claims for the affected period; voluntarily disclose to OIG under the Self-Disclosure Protocol if there is a material false-attestation pattern. If the entity intends to become 340B-registered, do not append JG until HRSA registration is complete and the OPAIS entry is active. |
| JG attested but drug not actually 340B-acquired (bucket error) | JG appended on a line where the dispensing system pulled the unit from non-340B GPO/wholesale stock without a planned 340B replenishment. This is a virtual-replenishment reconciliation failure — the attestation is false even though the entity is 340B-registered. | Submit a corrected claim removing JG (and accepting the standard ASP+6 percent payment with no 340B identification). Investigate and fix the dispensing-system bucket configuration. Run a reconciliation between 340B purchase orders and JG-tagged claims for the quarter; report and correct any variance over 1-2 percent. Persistent bucket errors are the highest-yield finding in HRSA 340B audits. |
| JG and TB both on the same line | Both 340B-identification modifiers appended to one claim line. JG and TB are mutually exclusive — the entity uses one or the other, not both. | Resubmit with only the correct modifier per entity sub-category. If unclear, default to the entity's primary 340B registration record in HRSA OPAIS. The both-on-same-line pattern is almost always a billing-system configuration bug rather than an intentional choice; fix at the system level. |
JG is appended by 340B-eligible hospital outpatient departments that are subject to the OPPS payment policy — primarily Disproportionate Share Hospitals (DSH) and other non-exempt 340B covered entities. TB is the parallel modifier for the carved-out 340B categories that were never subject to the OPPS payment cut: Rural Sole Community Hospitals (Rural SCHs), PPS-exempt Cancer Hospitals, and Children's Hospitals. Both modifiers identify 340B-acquired drug; the choice is determined by the entity type, not the drug.
No — not for claims dated on or after January 1, 2023. From January 1, 2018 through December 31, 2022, Medicare paid JG-tagged separately payable drugs at ASP minus 22.5 percent under the OPPS. After the Supreme Court ruled in American Hospital Association v. Becerra (June 2022) that the cut was unlawful, CMS reverted to the default OPPS rate of ASP plus 6 percent for both 340B and non-340B drugs effective with the CY 2023 OPPS Final Rule (CMS-1772-FC). JG-tagged drugs today are paid the same as non-340B drugs; the modifier remains a required identifier even though it no longer drives a different payment rate.
CMS-1793-F (the CY 2024 OPPS remedy rule) directed a one-time lump-sum remedy payment to 340B hospitals that were underpaid for separately payable drugs from January 1, 2018 through September 27, 2022 (the period before CMS implemented the default rate mid-year in CY 2022). CMS began issuing the lump-sum payments through MACs in early 2024. The remedy was funded by a budget-neutral 0.5 percent reduction to OPPS payments for non-drug items and services applied prospectively over approximately 16 years starting CY 2026.
Hospitals manage 340B inventory two ways: virtual replenishment (drug is pulled from regular GPO/wholesale stock, billed, and then replenished from 340B at the end of the accumulation period) or physical 340B-only stock. JG attests that the specific dispensed unit was 340B-acquired by the time the claim was submitted. In a replenishment model, the dispensing software must reconcile each administered unit to the correct virtual bucket (340B vs non-340B) before the claim drops; mis-bucketing is the most common audit finding. Apexus and 340B Health publish guidance on bucket reconciliation; the 340B Office of Pharmacy Affairs treats split-billing accuracy as a compliance requirement.
Medicare Advantage plans are not bound by the OPPS payment methodology in the same way Traditional Medicare is, so JG/TB reporting requirements depend on the individual MA plan's policy. Most large MA plans follow CMS conventions and accept (or require) JG on 340B drug claims for parity with Traditional Medicare data. A few MA plans have historically used JG data to negotiate lower contracted rates for 340B drugs, which is a separate commercial dispute. Confirm the JG requirement plan-by-plan; the safest default for a 340B hospital is to append JG on MA claims unless the plan policy explicitly says otherwise.
Commercial payers generally do not require JG. Some commercial plans have introduced their own 340B-identification requirements through contract amendments, often demanding price transparency or a 340B-specific reimbursement schedule — but those are payer-specific policies, not HCPCS modifier requirements. Appending JG to a commercial claim where it is not required is usually harmless but can occasionally route the claim into a payment-policy review queue. Confirm with each commercial payer's medical drug policy before applying JG outside Medicare.
JG (and TB) attests under penalty of False Claims Act exposure that the drug was acquired through the 340B Drug Pricing Program. Two scenarios create direct audit risk: (1) JG appended to a drug that was NOT actually 340B-acquired (e.g., a replenishment-bucket error) — this is a misrepresentation and can trigger OIG audit and recoupment; (2) JG omitted from a 340B drug — historically caused underpayment to the hospital during the 2018-2022 cut window, and going forward creates a data-integrity gap. HRSA audits the 340B program separately; CMS audits payment accuracy. A consistent mismatch between 340B purchase records and JG-tagged claims is the highest-yield finding in both audit tracks.
JG is independent of biosimilar policy: if a biosimilar was acquired through 340B, JG (or TB, by entity type) goes on the biosimilar HCPCS code (for example Q5127 for Stimufend, Q5121 for Avsola) the same way it would on the reference product. The CY 2024 OPPS rule continued to pay biosimilars at ASP plus 8 percent during the initial five-year qualifying period; JG does not change that rate today but does keep the 340B audit trail intact. Biosimilars complicate replenishment-bucket reconciliation because the dispensing system must track 340B status per HCPCS, not per molecule.
All sources are publicly available federal publications or paraphrased from trade-association educational materials. The methodology by which we resolve source disagreements is described in the Methodology.