What is NADAC?
NADAC — National Average Drug Acquisition Cost — is a weekly drug cost benchmark published by the Centers for Medicare & Medicaid Services (CMS). It reflects the average price community pharmacies pay to acquire prescription and OTC drugs, based on actual invoice data collected through voluntary pharmacy surveys.
Published by
CMS
Cadence
Weekly
Level
NDC
Source
Pharmacy invoices
How NADAC is Collected
CMS contracts with a survey vendor (currently Myers and Stauffer) to collect weekly invoice data from a stratified random sample of retail community pharmacies. Participation is voluntary. Pharmacies submit actual purchase invoices, which are then aggregated to produce an average acquisition cost per NDC.
Survey issued weekly
CMS surveys a rotating sample of retail pharmacies — chain, independent, mail order, and long-term care.
Invoices collected
Participating pharmacies submit invoice data reflecting what they paid to purchase drugs from wholesalers or manufacturers.
Aggregated per NDC
Acquisition costs are averaged by NDC and pharmacy type (retail, mail order, LTC). Outliers are reviewed.
Published each Monday
NADAC files are posted to the CMS website every Monday and include an effective date. Historical files are archived.
NADAC vs. Other Pricing Benchmarks
The US drug pricing landscape has multiple benchmarks that serve different purposes. NADAC is one of the most transparent — it is based on actual transaction data rather than published list prices.
| Benchmark | Publisher | Cadence | Basis |
|---|---|---|---|
| NADAC | CMS | Weekly | Actual pharmacy invoice data (voluntary survey) |
| AWP | Compendia (Red Book, Medi-Span) | Varies | Published list price (manufacturer-set) |
| WAC | Manufacturer | Varies | Manufacturer's list price to wholesalers |
| ASP | CMS | Quarterly | Average net selling price (after rebates) |
Key Use Cases
Medicaid reimbursement
Many state Medicaid programs use NADAC as the basis for ingredient cost reimbursement to pharmacies, replacing AWP-based formulas.
PBM contract benchmarking
Analysts use NADAC as a transparent benchmark to evaluate whether PBM contracts are pricing drugs at reasonable acquisition cost levels.
Formulary cost modeling
Health plans model the per-unit cost of formulary alternatives using NADAC to estimate the pharmacy cost of utilization shifts.
Generic substitution analysis
NADAC's NDC-level granularity allows comparison of acquisition costs across generic manufacturers for the same drug form and strength.
NADAC Data Structure
The CMS NADAC file is NDC-level with an effective date, allowing historical pricing queries. Each row represents a single NDC's acquisition cost for a given week.
| Field | Description |
|---|---|
| ndc | 11-digit NDC (flat, no hyphens) |
| as_of_date | Effective date of the NADAC rate |
| ndc_description | Plain-language drug description |
| nadac_per_unit | NADAC price per dispensing unit (tablet, mL, etc.) |
| pricing_unit | Unit of measure: EA (each), ML, GM |
| pharmacy_type_indicator | R = Retail, I = Independent, M = Mail order, LTC = Long-term care |
| classification_for_rate_setting | B = Brand, G = Generic, OTC = Over the counter |
Example — latest NADAC rate for a drug
SELECT
n.ndc,
n.ndc_description,
n.nadac_per_unit,
n.pricing_unit,
n.as_of_date
FROM nadac_pricing n
WHERE n.ndc = '00071021340'
ORDER BY n.as_of_date DESC
LIMIT 1;Sample Data — nadac_pricing Table
Below is a representative sample from the TwinFyRx nadac_pricing table, showing actual per-unit acquisition costs by NDC for a single weekly snapshot.
| ndc | description | nadac_per_unit |
|---|---|---|
| 00071021340 | ATORVASTATIN CALCIUM 10 MG TABLET | $0.0410 |
| 00071021390 | ATORVASTATIN CALCIUM 10 MG TABLET | $0.0389 |
| 00378395105 | AMLODIPINE BESYLATE 5 MG TABLET | $0.0152 |
| 68180031302 | LISINOPRIL 10 MG TABLET | $0.0198 |
| 00228257211 | METFORMIN HCL 500 MG TABLET | $0.0215 |
| 00591040701 | OMEPRAZOLE 20 MG DR CAPSULE | $0.0340 |
| 00003089321 | APIXABAN 5 MG TABLET (ELIQUIS) | $17.4982 |
| 00378181110 | LEVOTHYROXINE SODIUM 50 MCG TABLET | $0.1326 |
| 27241005003 | GABAPENTIN 300 MG CAPSULE | $0.0312 |
| 00002322230 | DULOXETINE HCL 30 MG DR CAPSULE | $0.0745 |
10 rows from a weekly NADAC snapshot. Brand drugs (highlighted) typically cost significantly more per unit. Download a free sample.
How TwinFyRx handles NADAC
TwinFyRx ingests the weekly CMS NADAC file into the nadac_pricing table, keyed by ndc + as_of_date. A convenience view vw_nadac_latest returns only the most recent rate per NDC, which can be joined to the drug hierarchy via the ndc_rxnorm crosswalk.