The Standard Vocabulary is a foundational tool developed by the OMOP team to enable transparent and consistent content across disparate observational databases, and serves to support the OMOP research community in conducting efficient and reproducible observational research.

The Standard Vocabulary contains all of the code sets, terminologies, vocabularies, nomenclatures, lexicons, thesauri, ontologies, taxonomies, classifications, abstractions, and other such data that are required for:
1. Creating the transformed (i.e., standardized) data from the raw data sets,
2. Searching and querying the transformed data, and browsing and navigating the hierarchies of classes and abstractions inherent in the transformed data
3. Interpreting the meanings of the data.

Using the vocabularies with your data

All content in your data, such as drugs or conditions, are referred to by concepts. You therefore need the Standard Vocabularies to understand and make use of these concepts. The Standard Vocabularies also provide you with additional class concepts, relationships and ancestry relationships between concepts and a source to concept map that you need to convert non-standard vocabularies to Standard Vocabularies during the ETL process of your data.

In order to use the Standard Vocabularies, you must load them into the database or SAS file system next to your data. For information about this, download the specifications, the DDL files and the vocabulary data files (see left panel).

Vocabulary releases

Vocabularies undergo constant changes: concepts are created, improved or deprecated because of bug fixes, changes in the data sources or the underlying reality of health care. For example, new drugs are developed and enter the market, new procedures are invented, and new diagnostic codes are introduced. Same is true for relationships and mappings.

We therefore release the vocabulary files quarterly and provide Release Notes. Sometimes, interim releases are necessary for urgent bug fixes or additions. Check the release schedule regularly, or sign up for release notifications.

The process by which we build the Standard Vocabularies is available as Open Source. We encourage the community to help improve the vocabulary build process. If you find problems or know of a better way, contact OMOP with your input.

Querying the vocabulary

The Standard Vocabularies are organized with the goal in mind that all vocabularies are represented in the same fashion, no matter their origin. They can therefore be queried in a standardized fashion. OMOP is holding a collection of Standard Queries to answer typical questions relevant for data researchers, such as identification of conditions and drugs, membership in classifications, etc.

License information

For the most part, vocabularies have been adapted from public or proprietary sources. There are very few vocabularies created de-novo by OMOP. All publically available Vocabularies are called "unrestricted" and are distributed in a file that is Open Source, licensed under the Apache License Version 2.0. Some third party vocabularies (called "restricted") are only available to be used for certain research purposes and an End User License Agreement (EULA) has to be executed. Please contact OMOP if you need access to the restricted licensed material (see table).

Domain Type Vocabulary Restricted
Demographic Standard terminology HL7 Administrative Sex
OMB Ethnicity
CDC Race
Drug Standard terminology RxNorm
VA Class
Mapped coding scheme Cerner Multum
FDB Drug Product Yes
FDB Indication Yes
Medi-Span GPI Yes
Multilex Yes
VA Product
Condition Standard terminology, classification SNOMED-CT
Mapped coding scheme ICD-10-CM
Procedure Standard classification SNOMED-CT
Standard terminology ICD-9-Procedure
CPT-4 Yes
Mapped coding scheme ICD-10-PCS
Cohort Analysis SMQ Yes
Observation Standard terminology, classification SNOMED-CT
Standard classification LOINC Multidimentional Classification
Provider Standard terminology NUCC
CMS Speciality
Visit Standard terminology OMOP Visit
CMS Place of Service
Cost Standard classification MDC
Standard terminology Revenue Code
Concept Type Standard terminology OMOP Condition Occurance Type
OMOP Procedure Occurance Type
OMOP Observation Type
OMOP Drug Exposure Type
OMOP Death Type

Latest Release Version 4.4 2014-04-11

Next Release:4.4. Aug-2014
  • Data files (unrestricted): CSV  SAS
  • Data files (restricted): CSV  SAS
  • Standard Vocabulary Specification
  • Vocabulary table DDL
  • Latest Release Notes
  • Release schedule
  • Register for release notification
  • Standardized Vocabulary queries
  • Vocabulary build process
  • Minimal Detectable Relative Risk
  • FDA approval dates
  • Drug strength
  • Change requests to vocabulary


    All material unless otherwise specified (restricted) is licensed under the Apache License Version 2.0, making it available to the public as Open Source with minimal restrictions.
    To learn more about what you need to do to use the OMOP Vocabulary, please review the License.