Medical coding systems are common vocabularies that allow specific identification of different clinical concepts. There are a number of common and widely used medical coding systems, such as ICD-10-CM, SNOMED, and others. However, different healthcare IT systems use all kinds of coding systems - some standardized, some proprietary. Metriport enriches data with code system lookup, normalization, and cross-walks, so that the result is cohesive and more robust than it is at the source.Documentation Index
Fetch the complete documentation index at: https://docs.metriport.com/llms.txt
Use this file to discover all available pages before exploring further.
Common Medical Coding Systems
Below is an overview of the most prevalent coding systems supported by Metriport and often found in the source documents:| Coding System | Identifiers | Purpose | FHIR Resources | Example | Maintained by |
|---|---|---|---|---|---|
| ICD-10-CM (International Classification of Diseases, 10th Revision, Clinical Modification) | OID: 2.16.840.1.113883.6.90 URL: http://hl7.org/fhir/sid/icd-10-cm | Encodes medical diagnoses and conditions | Condition | E11.9 → Type 2 diabetes mellitus without complications | U.S. National Center for Health Statistics (NCHS) |
| CPT (Current Procedural Terminology) | OID: 2.16.840.1.113883.6.12 URL: http://www.ama-assn.org/go/cpt | Encodes outpatient medical procedures and services | Procedure | 0331T → Myocardial sympathetic innervation imaging, planar qualitative and quantitative assessment | American Medical Association (AMA) |
| CVX (Vaccine Codes) | OID: 2.16.840.1.113883.12.292 URL: http://hl7.org/fhir/sid/cvx | Identifies vaccines and vaccine groups | Immunization | 125 → Novel Influenza-H1N1-09, live virus for nasal administration | U.S. Centers for Disease Control and Prevention (CDC) |
| SNOMED CT (Systematized Nomenclature of Medicine – Clinical Terms) | OID: 2.16.840.1.113883.6.96 URL: http://snomed.info/sct | Encodes comprehensive clinical terminology for conditions, findings, and procedures | Condition, Procedure, and others | 44054006 → Diabetes mellitus type 2 (disorder) | SNOMED International |
| LOINC (Logical Observation Identifiers Names and Codes) | OID: 2.16.840.1.113883.6.1 URL: http://loinc.org | Encodes laboratory and clinical observations | Observation, Encounter, and others | 718-7 → Hemoglobin [Mass/volume] in Blood | Regenstrief Institute |
| NDC (National Drug Code) | OID: 2.16.840.1.113883.6.69 URL: http://hl7.org/fhir/sid/ndc | Identifies drug products marketed in the U.S. | Medication | 0002-8215-01 → insulin human (Humulin R) 100 [iU]/mL Parenteral Injection, Solution, 1 VIAL, MULTI-DOSE in 1 CARTON (0002-8215-01) / 10 mL in 1 VIAL, MULTI-DOSE | U.S. Food and Drug Administration (FDA) |
| RxNorm | OID: 2.16.840.1.113883.6.88 URL: http://www.nlm.nih.gov/research/umls/rxnorm | Normalizes drug names and clinical drugs | Medication | 311036 → HumuLIN R 100 UNT/ML Injectable Solution | U.S. National Library of Medicine (NLM) |
Other Clinical Classification Systems
These systems are typically not provided in the source documents, but are added by Metriport:| Coding System | Purpose | FHIR Resources | Example | Maintained by |
|---|---|---|---|---|
| CCSR (Clinical Classifications Software Refined) | Groups ICD-10-CM diagnosis codes into clinically meaningful categories across body systems | Condition | END002 → Diabetes mellitus without complication | U.S. Agency for Healthcare Research and Quality (AHRQ) |
| HCC (Hierarchical Condition Categories) | Groups ICD-10-CM diagnosis codes into hierarchical categories used for risk adjustment and reimbursement | Condition | 18 → Diabetes with chronic complications | U.S. Centers for Medicare & Medicaid Services (CMS) |
| CCIR (Chronic Condition Indicator Refined) | Classifies ICD-10-CM diagnosis codes as chronic or nonchronic across 18 clinical condition categories | Condition | C → Chronic | U.S. Agency for Healthcare Research and Quality (AHRQ) |
Representation in FHIR
Each of these coding systems appears in FHIR as elements ofcoding, category, or extension arrays.
Here’s a subset of attributes you can expect to find in a Condition resource, displaying how Metriport uses different coding systems to hydrate the clinical data:

