SOURCES, VERSIONS & WHAT CHANGED
NDC → ATC: ACD October 2026 release
An Actually Clean Data release with two kinds of change: refreshed source inputs and revised ACD processing.
October is the date of our release. It is not a claim that WHO issued a new ATC edition. Both new sources and improvements to our logic create new ACD versions; purchase eligibility is a separate question.
Source provenance: what went in
FDA directory: 2026-10-09. RxNorm Current Prescribable Content: 05-Oct-2026. ATCPROD version: 1.2026.7.
ATCPROD is NLM’s mapping-source version. We have not established the underlying WHO edition for this comparison. Exact March RxNorm and ATCPROD versions are unknown.
Processing lineage: what we changed
The old lookup could include classifications of related products or ingredients. This edition uses direct ATCPROD membership of the resolved drug product. NLM aims to assign a product class reflecting its most common indication; this is not an exhaustive indication or ingredient list.
We also use the retained Current Prescribable Content files to resolve NDCs, exclude ambiguous RxCUIs, and preserve original label case. The 16,455 additions and 19,552 removals are differences between delivered files. They combine source revisions and our method changes; they are not counts of newly approved or discontinued drugs.
Every input code is accounted for
162,167 of 256,748 distinct FDA package codes receive a classification across 632 ATC-4 groups. A missing current mapping does not prove that no historical or alternative mapping exists.
| Outcome | Package codes |
|---|---|
| classified | 162,167 |
| no atc4 | 1,116 |
| no current rxcui | 93,463 |
| unsupported ndc format | 2 |
A correction to our March coverage claim
The March download contained 162,051 distinct classified NDCs: 65.2% of its recorded 248,601 inputs. The 164,012 figure previously quoted counted intermediate RxCUI matches. That was a reporting error. The denominator and method also changed in October, so the percentages are not a like-for-like measure of quality.
Label changes need interpretation, too
Source capitalization is now preserved. All 145,712 retained pairs have some changed label casing. Ignoring case, 88 product names and 38 RxCUIs differ; ATC labels on retained pairs have no non-case differences.
Using the new edition
Import NDCs as text. Compare your own affected codes before replacing a March join. The ZIP includes a lookup-status table, field dictionary, example, and comparison report. New buyers pay $49 once. Verified March NDC purchasers are entitled to this mixed October release free because it includes improvements to our processing. Use your existing private download link, or contact support with your purchase receipt if you bought through WordPress or lost the link. Read our source-edition and revision policy. Not for clinical decisions.
Sources: FDA NDC directory, NLM Current Prescribable Content, and NLM ATCPROD. ATC classification: WHO Collaborating Centre for Drug Statistics Methodology. Independent preparation; no endorsement.
Get the October crosswalk · $49