This site is intended as a tool for personnel working within the Military Health System, although anyone with an interest may access. It contains no personal health or identifying information. It allows queries that detail current and historical associations between the following data elements:

ZIP Codes

Active and discontinued CONUS, U.S. Territory, and Overseas Military codes

TRICARE Health Care Service Region

North (i.e. 17), South (i.e. 18), West (i.e. 19)); Former Lead Agent Regions (i.e. 1-12, AK)); Territories (i.e. 14, 15, PR); NOTE: the official geographic definition of any TRICARE Region is found in the Managed Care Support Contract for that region. Region information on this site represents our best attempt to describe these contractual region definitions and should not be represented as official. Whenever a discrepancy in region definition exists between this data and the regional contract, the contract always takes precedence.

Military Treatment Facilities (MTF)

Current and Former Inpatient MTFs – MTFs are represented by Defense Medical Information System Identification (DMIS ID) numbers (for detailed information about DMIS IDs, visit the DMIS ID Table Home.

Catchment Area

Defined as a health care market area surrounding one or more MTFs. The catchment area identified in this data consists of a 40 mile radius (i.e. market area) around a current or former inpatient MTF. If the straight line distance from the MTF to a ZIP’s center is 40 miles or less, the ZIP is defined as a catchment ZIP within the MTF’s market area and associated with the MTF’s DMIS ID number. If a ZIP’s center is not within 40 miles of any active inpatient MTF, it is defined as non-catchment and associated with a state non-catchment DMIS ID. Historical information identifies ZIPs that used to be catchment when the MTF was active.

Appropriate Uses/Interpretation of Results

1. Determine a current or former Region for any ZIP Code, MTF, Town/City, State – Determine all or any part of a current or former Region by ZIPs, MTFs, Cities, States.
2. Determine the effective date of a change in Region code and an explanation of why it changed.
3. Determine the approximate distance between a ZIP and an MTF. Distances in this data represent straight-line distance (not drive time distance) from the CENTER of a ZIP (exact distance from other points within a ZIP to an MTF could differ significantly depending on size and shape of the ZIP).
4. Associate an MTF name and location with a DMIS ID number.

Click here to use the ZIP Tool