HL7 data types define the kind of data that can be included in a field, and are used throughout the HL7 message structure. Examples would be a string, formatted text, timestamp, address, or coded element. Each data type may contain additional data types that are referenced as components or subcomponents. Complex data types use other data types to define the kind of data they can contain.
Certain data types cannot reference each other due to the nature of the components. For instance, a data type cannot reference data types that already reference multiple components, because there is no way to code the information at that level.
Below is a list of the HL7 data types:
| DATA TYPE CATEGORY/ DATA TYPE | DATA TYPE NAME |
|---|---|
| Alphanumeric | |
| ST | String |
| TX | Text data |
| FT | Formatted text |
| Numerical | |
| CQ | Composite quantity with units |
| MO | Money |
| NM | Numeric |
| SI | Sequence ID |
| SN | Structured numeric |
| Identifier | |
| ID | Coded values for HL7 tables |
| IS | Coded values for user-defined tables |
| HD | Hierarchic designator |
| EI | Entity identifier |
| RP | Reference pointer |
| PL | Person location |
| PT | Processing type |
| Date/Time | |
| DT | Date |
| TM | Time |
| TS | Time stamp |
| Code Values | |
| CE | Coded element |
| CF | Coded element with formatted values |
| CK | Composite ID with check digit |
| CN | Composite ID number and name |
| CX | Extended composite ID with check digit |
| XCN | Extended composite ID number and name |
| Generic | |
| CM | Composite |
| Demographics | |
| AD | Address |
| PN | Person name |
| TN | Telephone number |
| XAD | Extended address |
| XPN | Extended person name |
| XON | Extended composite name and ID number for organizations |
| XTN | Extended telecommunications number |
| Specialty/Chapter specific | |
| CD | Channel definition |
| MA | Multiplexed array |
| NA | Numeric array |
| ED | Encapsulated data |
| CP | Composite price |
| FC | Financial class |
| Extended Queries | |
| QSC | Query selection criteria |
| QIP | Query input parameter list |
| RCD | Row column definition |
| Master Files | |
| DLN | Driver’s license number |
| JCC | Job code/class |
| VH | Visiting hours |
| Medical Records/Info Mgmt | |
| PPN | Performing person time stamp |
| Time Series | |
| DR | Date/time range |
| RI | Repeat interval |
| SCV | Scheduling class value pair |
| TQ | Timing/quantity |
Understanding components and subcomponents
A data type may reference one or more additional data types as components or subcomponents. For example, the CK (composite ID with check digit) data type can be broken down into four components, each referencing a specific data type. One of these components (HD) also references three other data types as subcomponents.
CK data type:
| SEQ | DATA TYPE | COMPONENT NAME |
|---|---|---|
| 1 | NM | ID Number |
| 2 | ST | Check Digit |
| 3 | ID | Code Identifying the Check Digit Scheme Employed |
| 4 | HD | Assigning Authority |
HD component:
| SEQ | DATA TYPE | COMPONENT NAME |
|---|---|---|
| 1 | IS | Namespace ID |
| 2 | ST | Universal ID |
| 3 | ID | Universal ID Type |
Want to learn more about HL7 and its Data Types? Enroll in the Academy’s HL7 training course now!
