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HCPCS J0637 · Level II · Part B drug

HCPCS J0637: Injection, caspofungin acetate, 5 mg

Reviewed by QuickIntell RCM Editorial Team · Last reviewed

Data effective
Data currency: ASP payment limits October 2026 (effective October 1, 2026); MUE and NCCI edits 2026 Q4 (effective October 1, 2026); OPPS Addendum B July 2026 (effective July 1, 2026). Next CMS release: January 1, 2027 (ASP, MUE, NCCI and OPPS quarterly updates).

Key facts for J0637

Billing unit
5 MG
Caspofungin acetate
ASP payment limit
$2.463
October 2026; -14.5% vs July 2026
Practitioner MUE
20
MAI 3
OPPS status
SI N
NCCI exposure
no PTP pairs
Coverage articles
0
none list this code

TL;DR

HCPCS J0637 is the Level II code for Injection, caspofungin acetate, 5 mg, billed per 5 MG. The Medicare Part B ASP payment limit for October 2026 is $2.463 per billing unit, down 14.5% from July 2026. The practitioner MUE allows up to 20 units per date of service (MAI 3). Under OPPS it carries status indicator N. J0637 is billed in units of 5 MG; the quantity administered, the NDC package and the units on the claim must reconcile, which is the check that prevents CARC 16 and 151 returns on this line. The ASP crosswalk maps 14 NDCs to it, sold as Cancidas, Caspofungin Acetate, Caspofungin by Merck Sharp & Dohme LLC, Sandoz Inc., Sagent Pharmaceuticals. No current Billing and Coding Article lists J0637, so coverage follows the FDA label, compendia and any applicable NCD.

Medicare Part B payment limit (ASP)

CMS sets the Part B payment limit for J0637 at $2.463 per 5 MG for October 2026, derived from manufacturer average sales price plus 6%, compared with $2.879 in July 2026. Beneficiary coinsurance is 20%.

ASP payment limits for J0637
QuarterPayment limitPerCoinsurance
October 2026$2.4635 MG20%
July 2026$2.8795 MG—
Source: CMS Medicare Part B Drug Payment Limit File. Commercial and Medicaid payers set their own rates.

NDC to HCPCS billing-unit conversion

The October 2026 ASP crosswalk maps 14 NDCs from 7 labelers to J0637. Report the NDC in the claim's drug segment and bill the number of J0637 units that equals the quantity administered divided by 5 MG; the last column gives units per full package.

NDCs that crosswalk to J0637
NDCDrug nameLabelerPackage sizeBilling units / package
00006-3822-10CancidasMerck Sharp & Dohme LLC1 × 110
00006-3823-10CancidasMerck Sharp & Dohme LLC1 × 114
00781-3421-94Caspofungin AcetateSandoz Inc.1 × 110
00781-3423-94Caspofungin AcetateSandoz Inc.1 × 114
25021-0194-10Caspofungin AcetateSagent Pharmaceuticals1 × 110
25021-0195-10Caspofungin AcetateSagent Pharmaceuticals1 × 114
59923-0613-70Caspofungin AcetateAreva Pharmaceuticals1 × 114
59923-0614-50Caspofungin AcetateAreva Pharmaceuticals1 × 110
63323-0356-10Caspofungin AcetateFreseniUS Kabi USA, LLC1 × 10100
63323-0358-10Caspofungin AcetateFreseniUS Kabi USA, LLC1 × 10140
70860-0106-10Caspofungin AcetateAthenex Pharmaceutical Division, LLC1 × 110
70860-0107-10Caspofungin AcetateAthenex Pharmaceutical Division, LLC1 × 114
72266-0106-01CaspofunginFosun Pharma USA Inc.1 × 110
72266-0107-01CaspofunginFosun Pharma USA Inc.1 × 114

Medically Unlikely Edits (MUE)

CMS publishes 3 MUE values for J0637. For practitioners the limit is 20 units per date of service with adjudication indicator 3, a date-of-service clinical edit: units above the limit deny but can be paid on appeal with documentation that the quantity was medically reasonable.

MUE values for J0637 by setting
SettingMUE (units/DOS)MAICMS rationale
Practitioner services203 Date of Service Edit: ClinicalPrescribing Information
Facility outpatient hospital203 Date of Service Edit: ClinicalPrescribing Information
DME supplier03 Date of Service Edit: ClinicalCMS Policy

NCCI edits and add-on relationships

No active practitioner PTP pair lists J0637 as a column-1 or column-2 code in v323r0. Drug supply codes are rarely bundled; the administration codes billed with them are where PTP edits usually apply.

J0637 is neither an add-on code nor a designated primary code in the 2026 Q4 NCCI add-on edit file.

Medicare coverage articles

No current Billing and Coding Article lists J0637 in its HCPCS table. Coverage then follows the drug's FDA label, compendia and any National Coverage Determination; check the Medicare Coverage Database before administering off-label.

Hospital outpatient (OPPS) status

In the July 2026 OPPS Addendum B, J0637 carries status indicator N. Status N means payment is packaged into the associated procedure and no separate OPPS payment is made.

Common denials for J0637 and how to prevent them

CARC 16 · M119

NDC missing, invalid or not matched to the HCPCS code

CARC 151 · N362

units billed exceed the MUE for the date of service

CARC 50 · N115

diagnosis not covered by the applicable coverage article or LCD

How QuickIntell checks J0637 before the claim leaves

QuickCode validates the NDC-to-unit conversion against the current ASP crosswalk, checks units against every published MUE setting and flags PTP and add-on conflicts on the same claim. QuickRCM routes CARC 16, 151 and 50 denials on drug lines with the matching coverage article attached so the appeal starts with evidence.

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Frequently asked questions — HCPCS J0637

What does HCPCS code J0637 describe?

J0637 is defined by CMS as "Injection, caspofungin acetate, 5 mg". Each billing unit represents 5 MG, so the units reported on the claim must equal the dose administered divided by that unit.

What is the Medicare reimbursement for J0637 in October 2026?

The ASP-based payment limit is $2.463 per 5 MG, with 20% beneficiary coinsurance. Medicare Administrative Contractors apply this limit; commercial payers use their own fee schedules. The July 2026 limit was $2.879.

How many units of J0637 can be billed per day?

The practitioner Medically Unlikely Edit is 20 units per date of service with adjudication indicator 3 (3 Date of Service Edit: Clinical). MAI 3 edits can be appealed with documentation that the units were medically reasonable. CMS cites "Prescribing Information" as the rationale.

Which NDCs map to J0637?

The October 2026 ASP crosswalk lists 14 NDCs from 7 labelers: Cancidas (Merck Sharp & Dohme LLC); Caspofungin Acetate (Sandoz Inc.); Caspofungin Acetate (Sagent Pharmaceuticals); Caspofungin Acetate (Areva Pharmaceuticals). For example NDC 00006-3822-10 is a 1 package equal to 10 billing units. The crosswalk's billing-units-per-package figure converts each package into J0637 units.

Does J0637 have NCCI bundling edits?

No active practitioner PTP pairs list J0637 as a column-1 or column-2 code in the v323r0 release. Unit limits (MUE) and medical-necessity coverage rules still apply.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-01. Verify against the primary file before billing or contracting decisions.

Disclaimer

This page is an operational reference compiled from CMS publications: the Medicare Part B drug payment limit and NDC crosswalk files, NCCI MUE and add-on edit tables, aggregate PTP statistics, OPPS Addendum B and the Medicare Coverage Database. Payment limits are Medicare national amounts; commercial and Medicaid payers differ. CPT codes are shown as numbers only; CPT descriptors are copyright AMA. Nothing here is legal, clinical or billing advice.