Visit codes are standardized using the following terminologies:

• Place of Service: CMS Place of Service Codes, maintained by The Centers for Medicare & Medicaid Services (CMS), are two-digit codes placed on health care professional claims to indicate the setting in which a service was provided – vocabulary 14.
• OMOP Visit concepts – vocabulary_id 24.

All 49 currently valid Place of Service codes are loaded into the Concept table as level 1. There are three Visit concepts defined in table: