Handout · Cheat sheet
SNOMED CT vs ICD-10-CM
Clinical documentation vs billing — and how they map
Objective: Know when to use SNOMED CT vs ICD-10-CM, and how they relate.
At a glance
| Dimension | SNOMED CT | ICD-10-CM |
|---|---|---|
| Purpose | Clinical documentation (problem list) | Billing, statistics, reporting |
| Structure | Poly-hierarchy + relationships, ~350k concepts | Mono-hierarchy, chapters, ~70k codes |
| Granularity | Very fine; pre/post-coordination | Coarser; built for reimbursement |
| Identifier | Numeric concept id (44054006) | Alphanumeric (E11.9) |
| Steward | SNOMED International | WHO (ICD-10) · NCHS + CMS (CM) |
Mapping
- Use the official SNOMED CT → ICD-10-CM map — relationships are many-to-one or one-to-many, not 1:1.
- A map target can be exact, or carry a rule/choice (laterality, episode, combination).
- Never reverse-map ICD → SNOMED blindly; ICD loses clinical detail SNOMED keeps.
Which system for what
- Document the problem list in SNOMED CT · bill in ICD-10-CM.
- Procedures: CPT/HCPCS (outpatient) or ICD-10-PCS (inpatient) — not ICD-10-CM.
- Labs/observations = LOINC · medications = RxNorm.
Practise this
Practised at HealthAtoms · healthatoms.com — synthetic, educational reference.