# Gender Key: `identity.person.gender` Administrative gender per HL7 FHIR AdministrativeGender: male, female, other, or unknown. Matched case-insensitively (ac-02), so "Male"/"MALE" validate. Identities beyond the administrative four (e.g. non-binary) map to FHIR \`other\` at the data layer. Page: Samples: `Male`, `Female`, `Other`, `Unknown` ## Background ### Origin HL7 FHIR's AdministrativeGender value set is defined as the gender of a person used for administrative purposes.[[1]](https://www.hl7.org/fhir/valueset-administrative-gender.html) Its code system has four codes: male, female, other and unknown.[[2]](https://hl7.org/fhir/codesystem-administrative-gender.html) The value set is owned by HL7's Patient Administration Work Group.[[1]](https://www.hl7.org/fhir/valueset-administrative-gender.html) It has been normative since FHIR v4.0.0.[[1]](https://www.hl7.org/fhir/valueset-administrative-gender.html) FHIR defines Patient.gender as the gender that the patient is considered to have for administration and record keeping purposes.[[3]](https://hl7.org/fhir/patient-definitions.html) FHIR says this gender is needed to identify the individual, in combination with at least name and birth date.[[3]](https://hl7.org/fhir/patient-definitions.html) FHIR notes that the gender might not match the biological sex as determined by genetics or the individual's preferred identification.[[3]](https://hl7.org/fhir/patient-definitions.html) HL7 version 2's administrative sex table uses single-letter codes, including F for female, M for male, O for other and U for unknown.[[4]](https://terminology.hl7.org/CodeSystem-v2-0001.json) That version 2 table also has codes for ambiguous, not applicable and non-binary.[[4]](https://terminology.hl7.org/CodeSystem-v2-0001.json) ISO/IEC 5218 is a separate standard that codes human sexes as 0 for not known, 1 for male, 2 for female and 9 for not applicable.[[5]](https://en.wikipedia.org/wiki/ISO/IEC_5218) ### Use FHIR's comment on the unknown code says it means a proper value is applicable but not known.[[2]](https://hl7.org/fhir/codesystem-administrative-gender.html) Keep unknown apart from an empty cell: the first is a recorded answer, while a blank may only mean that nobody filled the field in. (Meridian's view) FHIR says systems should not infer any specific clinical meaning from Patient.gender without pre-coordination with exchange partners.[[6]](https://hl7.org/fhir/patient.html) FHIR offers separate extensions for gender identity and for sex parameter for clinical use.[[6]](https://hl7.org/fhir/patient.html) FHIR notes that the vast majority of systems and contexts only support male and female.[[3]](https://hl7.org/fhir/patient-definitions.html) Treat this column as a record-keeping field, and look for a dedicated field before using it for any clinical or identity question. (Meridian's view) When combining it with HL7 version 2 or numerically coded files, build an explicit mapping table rather than translating codes by eye. (Meridian's view) ## Sources 1. [Valueset-administrative-gender - FHIR v5.0.0](https://www.hl7.org/fhir/valueset-administrative-gender.html) — standard 2. [Codesystem-administrative-gender - FHIR v5.0.0](https://hl7.org/fhir/codesystem-administrative-gender.html) — standard 3. [Patient - FHIR v5.0.0](https://hl7.org/fhir/patient-definitions.html) — standard 4. [administrativeSex](https://terminology.hl7.org/CodeSystem-v2-0001.json) — standard 5. [ISO/IEC 5218 - Wikipedia](https://en.wikipedia.org/wiki/ISO/IEC_5218) — secondary source 6. [Patient - FHIR v5.0.0](https://hl7.org/fhir/patient.html) — standard