National Drug Code
Intelligence Center
Explore NDC billing, reimbursement, and denial-prevention education. Search the DenialPro NDC reference data, learn drug billing fundamentals, use interactive calculators, and investigate NDC-related denials.
Important: NDC billing requirements vary by payer and are updated periodically. Always verify with current CMS guidelines, payer-specific NDC policies, and the FDA NDC Directory. This information is for educational purposes only and does not guarantee payment or coding accuracy.
NDC Database Search
Search by NDC number, drug name, brand name, generic name, HCPCS/J-code, CPT code, manufacturer, or keyword. Each record includes full NDC details, billing requirements, and common denials.
Sample data for educational purposes. Always verify NDCs against the FDA NDC Directory and current payer requirements.
NDC Billing Learning Center
25+ educational modules covering everything from NDC fundamentals to payer-specific billing rules.
What is an NDC?
NDC Fundamentals
Understand the National Drug Code — the universal product identifier for drugs in the U.S.
- NDC = 10-digit, 3-segment universal drug product identifier
- Assigned by FDA to manufacturers, repackagers, and labelers
- Required on claims for physician-administered drugs (medical benefit)
Understanding NDC Structure
NDC Fundamentals
Learn the three segments of an NDC: Labeler Code, Product Code, and Package Code.
- 3 segments: Labeler Code + Product Code + Package Code
- Labeler Code = manufacturer/repackager (FDA-assigned)
- Product Code = specific drug product (labeler-assigned)
Examples:
- NDC 31747-0591-01: Labeler=31747 (Camber), Product=0591, Package=01
Reading an NDC Label
NDC Fundamentals
How to read an NDC on a drug label and identify the key billing information.
- NDC appears on drug label/package with hyphens separating segments
- Identify: Labeler Code, Product Code, Package Code
- Also capture: drug name, strength, dosage form, route, package size
10-Digit vs 11-Digit NDC
Format & Conversion
Understand why the FDA uses 10 digits but CMS requires 11 digits for billing.
- FDA assigns 10-digit NDCs with variable segment lengths
- CMS requires 11-digit format (5-4-2) on all claims
- 11-digit format eliminates ambiguity and ensures consistent processing
Why Billing Requires the 11-Digit Format
Format & Conversion
The business and compliance reasons behind the 11-digit billing requirement.
- 5-4-2 structure enables consistent automated processing
- Eliminates ambiguity from variable-length 10-digit formats
- Required by Medicare, Medicaid, and most commercial payers
Leading Zero Conversion Examples
Format & Conversion
Step-by-step examples of converting 10-digit NDCs to 11-digit format using leading zeros.
- Pad each segment with LEADING zeros only
- Target lengths: Labeler=5, Product=4, Package=2
- Never add trailing zeros or change the numeric value
Examples:
- NDC 1234-567-89 (4-3-2) → 01234-0567-89 (5-4-2): pad labeler to 5, product to 4
- NDC 12345-678-9 (5-3-1) → 12345-0678-09 (5-4-2): pad product to 4, package to 2
HCPCS and NDC Relationships
HCPCS & Code Relationships
How HCPCS codes and NDCs work together on a claim.
- HCPCS = billing code; NDC = specific product identifier
- One HCPCS code maps to many NDCs
- NDC submitted in 2410 loop of 837P claim
J Codes
HCPCS & Code Relationships
Understanding J-codes — the HCPCS codes used for physician-administered drugs.
- J-codes = HCPCS Level II codes for non-self-administered drugs
- Each J-code specifies the drug name and billing unit
- Used on 837P (professional) and 837I (outpatient) claims
Examples:
- J9035: Injection, bevacizumab, 10 mg (unit = 10 mg)
- J9272: Injection, pembrolizumab, 1 mg (unit = 1 mg)
Common CPT Relationships
HCPCS & Code Relationships
How CPT administration codes pair with drug J-codes.
- CPT codes bill the administration; J-codes bill the drug
- Chemo administration: 96400-96549
- Non-chemo IV: 96360-96379
Drug Billing Basics
Drug Billing Basics
Core concepts for billing physician-administered drugs.
- 3 key elements: correct J-code, correct NDC (11-digit), correct units
- Buy and bill: provider purchases and bills the drug
- White bagging: specialty pharmacy ships drug to provider
Physician Office Drug Billing
Drug Billing Basics
NDC reporting requirements for physician office drug billing.
- 837P claim, NDC in 2410 loop, 11-digit format
- J-code + NDC + units + UOM on same line item
- Document drug name, NDC, dose, route, indication in medical record
Hospital Outpatient Drug Billing
Drug Billing Basics
NDC reporting under hospital outpatient (OPPS) billing.
- 837I claim under OPPS, NDC in 2410 loop, 11-digit format
- Most drugs packaged into APCs; high-cost drugs paid separately
- Revenue code 0636 for drugs requiring specific identification
Infusion Billing
Drug Billing Basics
Coding and billing for drug infusions, including time-based codes.
- Time-based CPT codes: 96360-96379 for infusions
- Chemo infusion: 96413 (initial), 96415 (additional), 96417 (concurrent)
- Drug (J-code) billed separately from administration (CPT)
Injection Billing
Drug Billing Basics
Coding and billing for IV, IM, and subcutaneous drug injections.
- 96372 = IM/SC therapeutic injection
- 96374 = IV push (initial), 96375 = each additional
- Chemo IV push: 96411-96412
Vaccine Billing
Drug Billing Basics
Vaccine billing — vaccine codes, administration codes, and NDC requirements.
- Vaccine product code + administration code (90460-90474)
- NDC may be required for Medicaid and immunization registries
- Part B: flu, pneumococcal, COVID-19, hep B (high-risk); Part D: most others
Specialty Drug Billing
Drug Billing Basics
Key considerations for billing specialty drugs (biologics, orphan drugs, compounded drugs).
- Specialty drugs = high-cost, often require prior auth
- Verify prior auth before administering
- Some payers mandate white bagging (no buy and bill)
Drug Wastage
JW, JZ & Wastage Modifiers
Understanding drug wastage — when it occurs and how to bill it.
- Wastage = discarded drug from a single-use vial
- Billable to Medicare Part B with JW modifier on a separate line
- Only for single-use vials — multi-dose vials have no billable wastage
JW Modifier
JW, JZ & Wastage Modifiers
When and how to use the JW modifier for discarded single-use vial drugs.
- JW = drug discarded from a single-use vial, not administered to any patient
- Required for Medicare Part B when wastage occurs
- Reported on a SEPARATE line item from the administered dose
Examples:
- 100 mg vial, 80 mg administered → Line 1: 80 mg (no modifier), Line 2: 20 mg JW
JZ Modifier
JW, JZ & Wastage Modifiers
When and how to use the JZ modifier to attest zero discard from a single-use vial.
- JZ = attests zero discard from a single-use vial
- Required for Medicare Part B when entire vial was administered
- Reported on the SAME line as the drug HCPCS code
Examples:
- 100 mg vial, 100 mg administered → 100 mg with JZ modifier
Units of Measure (UN, ML, GR, F2)
Units & Calculations
Understanding CMS Unit of Measure (UOM) codes and when to use each.
- UN = Unit, ML = Milliliter, GR = Gram, MG = Milligram, F2 = International Unit
- UOM submitted with NDC in 2410 loop
- Must match NDC package size and HCPCS description
Calculating Billable Units
Units & Calculations
How to calculate the correct number of billable units from the dose and J-code definition.
- Billable Units = Amount Administered ÷ HCPCS Unit Definition
- Units must match the NDC submitted on the claim
- Wastage: administered units + JW discard units = total
Examples:
- J9035 (10 mg/unit): 50 mg administered → 5 units
- J9272 (1 mg/unit): 200 mg administered → 200 units
Package Size & Dosage Calculations
Units & Calculations
How to calculate the number of vials needed and verify package size against billing units.
- Vials Needed = Dose Required ÷ Vial Size (round up)
- NDC must match the vial actually used
- Package size must match the NDC label and FDA directory
Examples:
- 150 mg dose, 100 mg vials → 2 vials, 50 mg wasted (JW)
- 75 mg dose, 100 mg vials → 1 vial, 25 mg wasted (JW)
Documentation Requirements
Documentation & Medical Necessity
Essential documentation for drug billing — what to record for every administered drug.
- Document: drug name, HCPCS, NDC, dose, route, indication
- Record vial size, amount drawn, amount administered, amount discarded
- Single-use vial: document discard amount, reason, date/time
Medical Necessity
Documentation & Medical Necessity
How to establish and document medical necessity for drug therapy.
- Diagnosis (ICD-10) must support the drug use
- Off-label use may require additional documentation and payer policy verification
- Medicare covers some off-label uses if listed in compendia (NCCN, AHFS)
Prior Authorization Considerations
Documentation & Medical Necessity
When prior authorization is required for drugs and how to manage the process.
- Obtain PA BEFORE administering — no retroactive PA
- Common for high-cost and specialty drugs
- PA includes diagnosis, drug, dose, rationale, clinical info
Medicare Drug Billing
Payer-Specific Billing
Medicare Part B drug billing — NDC requirements, JW/JZ modifiers, and ASP pricing.
- Part B: NDC required (11-digit), ASP + 6% pricing
- JW/JZ required for ALL single-use vial claims
- NDC + UOM + units in 2410 loop, all consistent
Medicaid Drug Billing
Payer-Specific Billing
State Medicaid NDC requirements — varies by state, often stricter than Medicare.
- NDC required — requirements vary by state
- Reimbursement often based on NADAC or state formulas
- Some states require NDC for ALL drug claims
Commercial Payer Differences
Payer-Specific Billing
How commercial payer drug billing differs from Medicare and Medicaid.
- NDC requirements vary by payer — check provider manual
- Reimbursement: AWP, ASP, or negotiated rates
- PA requirements vary — some require PA for most specialty drugs
Interactive Calculators
Tools to help you convert NDCs, calculate billable units, and determine drug wastage.
NDC 10-to-11 Digit Converter
Convert a 10-digit FDA NDC to the 11-digit CMS billing format (5-4-2) by adding leading zeros to each segment.
NDC Unit Calculator
Calculate billable units: Billable Units = Amount Administered ÷ HCPCS Unit Definition
e.g., 50 mg
e.g., 10 mg/unit (from J-code)
Drug Wastage Calculator
Determine the required modifier (JW, JZ, or none) and billable wastage for single-use and multi-dose vials.
Future: HCPCS ↔ NDC Crosswalk
An automated crosswalk between HCPCS/J-codes and NDCs is planned for a future release.
NDC Denial Education
Searchable education for common NDC-related denials and rejections — root causes, prevention tips, and resolution steps.
Missing NDC
The NDC was not submitted on the claim for a physician-administered drug.
The NDC was not entered in the billing system, or the system was not configured to report the NDC in the 2410 loop. This is common when billing staff are unaware of the NDC requirement or when the drug was added to the system without an NDC.
Investigate this denialInvalid NDC
The NDC submitted does not match any product in the FDA NDC Directory.
The NDC was transcribed incorrectly, the NDC was from a discontinued product, or the wrong NDC was selected from the billing system. The NDC does not exist in the FDA NDC Directory.
Investigate this denialIncorrect NDC Format
The NDC was submitted in 10-digit format instead of the required 11-digit CMS format.
The billing system was not configured to convert 10-digit NDCs to 11-digit format, or the NDC was manually entered in 10-digit format without conversion.
Investigate this denialIncorrect Quantity
The number of units billed does not match the amount administered.
The billing staff calculated units incorrectly (e.g., billed 1 unit for a 10 mg J-code when 50 mg was administered), or the wrong J-code was used with a different unit definition.
Investigate this denialIncorrect Units / UOM Mismatch
The unit of measure (UOM) does not match the NDC or HCPCS code description.
The UOM was selected incorrectly, or the billing system defaulted to the wrong UOM. The UOM must match both the NDC package size and the HCPCS code description.
Investigate this denialHCPCS/NDC Mismatch
The NDC submitted does not correspond to the HCPCS code on the claim.
The wrong NDC was selected from the billing system, or the wrong J-code was entered for the drug administered. The NDC and J-code must both identify the same drug product.
Investigate this denialDrug Not Covered
The payer does not cover the drug or the NDC submitted for the diagnosis.
The drug is not on the payer's formulary, the diagnosis does not match the FDA-approved indication, or the plan excludes the drug benefit.
Investigate this denialMissing Authorization
Prior authorization was not obtained or has expired for a drug requiring PA.
PA was not obtained before the drug was administered, the PA expired before the date of service, or the PA reference number was not included on the claim.
Investigate this denialDrug Wastage Errors
Incorrect reporting of JW or JZ modifiers for single-use vial drugs.
Billing staff did not know whether the drug was in a single-use or multi-dose vial, the JW/JZ modifier was omitted, or the wastage amount was calculated incorrectly.
Investigate this denialMedical Necessity Denial
The drug is not deemed medically necessary for the diagnosis.
The diagnosis (ICD-10) does not support the drug use, the use is off-label without adequate documentation, or the drug does not meet the payer's medical necessity criteria.
Investigate this denialMissing Drug Documentation
Required documentation for the drug claim is missing or insufficient.
The medical record does not document the drug name, NDC, dose, route, or indication. The documentation may be missing key elements required by the payer.
Investigate this denialDrug Package Mismatch
The NDC package size does not match the units billed.
The wrong NDC was selected (different package size), or the units were calculated based on a different vial size than the NDC submitted.
Investigate this denialOfficial References
Authoritative sources for NDC requirements, JW/JZ modifiers, and drug pricing.
FDA NDC Directory
Search the FDA NDC Directory for all registered drug products.
CMS NDC Billing Requirements
CMS guidance on NDC reporting for physician-administered drugs.
CMS JW/JZ Modifier Guidance
CMS guidance on the JW and JZ modifiers for drug wastage.
AMA HCPCS Code Book (Current)
HCPCS code descriptions for drug administration codes (J-codes).
CMS Medicare Drug Pricing
CMS ASP drug pricing files for reimbursement rates.
CMS Medicaid Drug Coverage
Medicaid drug coverage and reimbursement information.
Related Academy Lessons
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Connected Resources
Tools and resources for NDC and drug billing support.
Knowledge Center
In-depth articles on drug billing, NDC reporting, and modifier usage.
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