Commonly Used Terminologies
This guide provides a comprehensive reference for the most commonly used code systems and valuesets in healthcare applications. Each section includes the FHIR system
URLs needed for proper coding in FHIR resources.
Overview of Common Code Systems
The following table shows the most commonly used code system for each clinical application area:
Clinical Application | Primary Code System | CodeSystem URL | Description | Full System Valueset |
---|---|---|---|---|
Clinical Findings | LOINC | http://loinc.org | Laboratory tests, vital signs, clinical observations | http://loinc.org/vs |
Medications | RXNorm | http://www.nlm.nih.gov/research/umls/rxnorm | Normalized medication names | http://www.nlm.nih.gov/research/umls/rxnorm/vs |
Procedures | CPT | http://www.ama-assn.org/go/cpt | Current Procedural Terminology | http://www.ama-assn.org/go/cpt/vs |
Diagnoses | ICD-10-CM | http://hl7.org/fhir/sid/icd-10-cm | International Classification of Diseases, Clinical Modification | http://hl7.org/fhir/sid/icd-10-cm/vs |
Vaccines | CVX | http://hl7.org/fhir/sid/cvx | Vaccine Administered | http://hl7.org/fhir/sid/cvx/vs |
Allergies (food + environmental) | SNOMED CT | http://snomed.info/sct | Substance and clinical concepts | http://snomed.info/sct/vs |
Use-case Specific ValueSets
Each clinical area has predefined sets of codes that cover the most common scenarios you'll encounter. While each clinical area has a primary code system, healthcare applications often need to support multiple coding systems for different use cases.
Clinical Findings and Laboratory Tests
Valueset Name | Description | Valueset URL | Example Values | Code Systems |
---|---|---|---|---|
Vital Signs Type | Codes for types of vital sign measurements and clinical observations | http://hl7.org/fhir/us/core/ValueSet/us-core-vital-signs | [8302-2] Body height , [8867-4] Heart rate , | LOINC |
Smoking Status | Codes for patient smoking status and tobacco use | http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.11.20.9.38 | [8517006] Ex-smoker | SNOMED CT |
Pregnancy Status | Codes for pregnancy status and related observations | http://hl7.org/fhir/us/core/ValueSet/us-core-pregnancy-status | [77386006] Pregnancy | SNOMED CT |
SDOH Assessment | Social determinants of health assessment codes | http://hl7.org/fhir/us/core/ValueSet/us-core-common-sdoh-assessments | [71802-3] Housing status | LOINC |
Sexual Orientation | Codes for sexual orientation and gender identity | http://hl7.org/fhir/us/core/ValueSet/us-core-sexual-orientation | [20430005] Heterosexual | SNOMED CT |
Allergies and Adverse Reactions
Allergy coding uses SNOMED CT for substance identification and RXNorm for medication allergies, following US Core 5.0.1 specifications.
Code System | System URL | Description | Use Cases |
---|---|---|---|
SNOMED CT | http://snomed.info/sct | Substance and clinical concepts | Food allergies, environmental allergies, clinical findings |
RXNorm | http://www.nlm.nih.gov/research/umls/rxnorm | Medication substances | Drug allergies, medication intolerances |
Common ValueSets
Valueset Name | Description | Valueset URL | Example Values | Code Systems |
---|---|---|---|---|
US Core Allergy Substance | Common substances for allergy and intolerance documentation including refutations | http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113762.1.4.1186.8 | [7980] Penicillin G | SNOMED CT, RXNorm |
Medications
For detailed information about medication coding systems including RxNorm and NDC, see Medication Code Systems.
Medical Procedures
Procedure coding varies by setting and purpose, with CPT being primary for billing.
Code System | System URL | Description | Use Cases |
---|---|---|---|
CPT | http://www.ama-assn.org/go/cpt | Current Procedural Terminology | Billing, procedure documentation |
HCPCS | https://www.cms.gov/Medicare/Coding/HCPCSReleaseCodeSets | Healthcare Common Procedure Coding System | Medicare/Medicaid billing, Value-based care, DME |
SNOMED CT | http://snomed.info/sct | Clinical procedure concepts | Clinical documentation, procedure notes |
ICD-10-PCS | http://www.cms.gov/Medicare/Coding/ICD10 | ICD-10 Procedure Coding System | Hospital inpatient billing |
Diagnoses and Conditions
Diagnosis coding primarily uses ICD-10-CM for standardized disease classification, with SNOMED CT providing more granular clinical concepts preferred in international settings.
Code System | System URL | Description | Use Cases |
---|---|---|---|
ICD-10-CM | http://hl7.org/fhir/sid/icd-10-cm | International Classification of Diseases, Clinical Modification | Primary diagnoses, billing, epidemiology |
SNOMED CT | http://snomed.info/sct | Clinical findings and disorders | Clinical documentation, problem lists |
Vaccines and Immunizations
Vaccine coding uses CVX codes for vaccine types and CPT codes for administration procedures.
Code System | System URL | Description | Use Cases |
---|---|---|---|
CVX | http://hl7.org/fhir/sid/cvx | Vaccine Administered | Immunization records, vaccine administration |
CPT | http://www.ama-assn.org/go/cpt | Vaccine administration procedures | Billing for vaccine administration |