Version 2.77

Part Description

LP16413-4   Hemoglobin A1c
Currently (2010), four standardization protocols exist for measuring Hgb A1c:

1. IFCC - designated as a Reference Method or RM (
2. NGSP - the long standing protocol used in the US and most other countries since the DCCT study (
3.JDS/JSCC - a protocol used in Japan, Spain and possibly other countries
4. Swedish - used in Sweden at least

Protocols 2-4 are known as Designated Comparison Methods (DCM) and have been connected to the Reference Method and each other through various regression equations.

Because of the high degrees of standardization within protocol it should no longer be necessary to specify a LOINC code with a method such as "HPLC", "electrophoresis" or anything else. Analytical instruments will be designed so that an Hgb A1c result can be traced back to a specific standardization protocol, so the important distinction will be the standardization protocol as described above and which will be carried in the method field.

A meeting of instrument manufacturers (presumably including Japanese) in Milan, Italy, December 12, 2007, agreed (among other items) that:

-All manufacturers should implement worldwide the traceability to the IFCC reference system for Hgb -A1c.
-All new instruments sold after January 1st, 2011 will report (as a result of an Hgb A1c test) both SI (mmol/mol - no decimals) and NGSP derived units (percentage - one decimal), in agreement with the Consensus Statement.
-Note they only committed to supporting protocol (1) and (2)

Different countries are adopting the international harmonization recommendations in different ways. We have information from the NGSP that the US will continue to report only Hgb A1c/NGSP, with the unit percent - i.e., no change. In Great Britain, labs have already started to report all results both as Hgb A1c (NGSP) in % and Hgb A1c (IFCC) in mmol/mol. In Canada, they are awaiting a recommendation from an expert panel. Any of these measures could be reported in the same units, but the convention for the reporting Hgb A1c under the new IFCC protocol will be to use units of mmol/mol to avoid confusion between the DCCT/NGSP and the IFFCC protocol.

LOINC has defined 59261-8 (Hemoglobin A1c/ in Blood) by IFCC protocol.

These protocols produce different results when expressed in the same units. For example, the equivalent of Hgb A1c (NGSP) of 6.5% is Hgb A1c (IFCC) is 4.8%.

The NGSP web site ( suggests the use of alternate measures, such as glycated albumen, for patients with severe iron deficiency, dialysis patients, and those with SS SC CC because of over or under reading that can occur with these interferences. It also describes the effect of abnormal hemoglobins on results of HbA1c by instrument.

Studies have demonstrated racial and ethnic differences in the relationship between glucose levels and hemoglobin A1C [22238408], and it has been suggested that some descendants of sub-Saharan Africa may have higher levels of measured hemoglobin A1C compared to glucose levels due to hemoglobin variants PMID: 31675503. Source: Regenstrief Help

Reference Information

Type Source Reference
Mapping Guidance Regenstrief Help Today, all US HbA1c measurements reported in the US and many other countries are standardized to the NGSP protocol and that has been true for years. This code [LOINC: 4548-4] should be used for reporting the HbA1c in the US. Other countries may report HbA1c measured by the IFCC protocol [LOINC: 59261-8], a protocol with results reported in units of mmol/mol. In Japan and parts of Spain it may be measured using the Japanese protocol. All three protocols produce different numeric values. Mapper’s Guide for the Top 2000 plus LOINC Laboratory Observations
Webcontent Lab Tests Online®Copyright Copyright © 2021 Lab Tests Online. All rights reserved. Hemoglobin A1c

Fully-Specified Name

Hemoglobin A1c/

Additional Names

Short Name
HbA1c MFr Bld
Display Name
HbA1c (Bld) [Mass fraction]
Consumer Name Alpha Get Info
HbA1c/Total Hgb, Blood

Basic Attributes

First Released
Version 1.0
Last Updated
Version 2.73
Change Reason
Release 2.70: CLASS: Changed Class from HEM/BC to CHEM as A1C tests are more correctly classified in CHEM.; Previous Releases: Changing from the property from Mass fraction to substance fraction has not effect on the meaning when the molecular weight of the numerator and the denominator are the same (for practical purposes). These terms had had a property of MFR in the past and we changed to SFR because we thought the LOINC community preferred SFR for HbA1c. But we mis understood the preference is to use the MFR variant- so we have changed back.
Order vs. Observation
Common Test Rank Get Info

Member of these Panels

LOINC Long Common Name
52745-7 Continuity Assessment Record and Evaluation (CARE) tool - Post Acute Care (PAC) - Discharge
52743-2 Deprecated Continuity Assessment Record and Evaluation (CARE) tool - Acute Care
52748-1 Deprecated Continuity Assessment Record and Evaluation (CARE) tool - Home Health Admission
52746-5 Deprecated Continuity Assessment Record and Evaluation (CARE) tool - Interim
52744-0 Deprecated Continuity Assessment Record and Evaluation (CARE) tool - Post Acute Care (PAC) - Admission
55399-0 Diabetes tracking panel
67868-0 End Stage Renal Disease (ESRD) Medical Evidence Report, Medicare Entitlement AndOr Patient Registration - OMB CMS form 2728
54037-7 HEDIS 2009 panel
57820-3 HEDIS 2010 panel
60442-1 HEDIS 2011 panel
67767-4 HEDIS 2012 panel
72199-3 HEDIS 2013 panel
74234-6 HEDIS 2014 Value Sets
75868-0 HEDIS 2015 Value Sets
79544-3 HEDIS 2016 Value Sets
82955-6 HEDIS 2017 Value Sets
87625-0 HEDIS 2018 Value Sets
90766-7 HEDIS 2019 Value Sets
94137-7 HEDIS 2020 Value Sets
96068-2 HEDIS MY 2020 Value Sets
43150-2 Hemoglobin A1c measurement device panel

Member of these Groups Get Info

LOINC Group Group Name
LG51070-7 Hemoglobin A1c/|MFr|Pt|ANYBldSerPl

Language Variants Get Info

Tag Language Translation
de-DE German (Germany) Hämoglobin A1c/Hämoglobin.gesamt:Massenfraktion:Zeitpunkt:Blut:Quantitativ:
Synonyms: HbA1c
de-AT German (Austria) Synonyms: Hämoglobin A1c
es-AR Spanish (Argentina) hemoglobina A1c/ón de masa:punto en el tiempo:sangre:cuantitativo:
es-MX Spanish (Mexico) Hemoglobina A1c / Hemoglobina total:Fracción de masa:Punto temporal:Sangre:Cuantitativo:
es-ES Spanish (Spain) Hemoglobina A1c (Hemoglobina glicosilada)/ón de masa:Punto temporal:Sangre:Qn:
Synonyms: Cuantitativo
et-EE Estonian (Estonia) Hemoglobiin A1c/hemoglobiin.üld:MFr:Pt:B:Qn:
Synonyms: Glükohemoglobiin Juhuslik Kvantitatiivne Veri
fr-FR French (France) Hémoglobine A1c/hémoglobine totale:Fraction massique:Ponctuel:Sang:Numérique:
fr-BE French (Belgium) Hémoglobine A1c/Hémoglobine.totale:Fraction de masse:Temps ponctuel:Sang:Quantitatif:
Synonyms: Hb Hb.totale HbA1c
fr-CA French (Canada) Hémoglobine A1c/Hémoglobine.totale:Fraction de masse:Temps ponctuel:Sang:Quantitatif:
it-IT Italian (Italy) Emoglobina A1c/Emoglobina.totale:MFr:Pt:Sangue:Qn:
Synonyms: Chimica Emoglobina A1c (HgB glicata ) Frazione di massa Punto nel tempo (episodio) Sangue
ko-KR Korean (Korea, Republic Of) 혈색소 A1C/총혈색소:질량분획:검사시점:전혈:정량:
nl-NL Dutch (Netherlands) hemoglobine A1c/hemoglobine.totaal:massafractie:moment:bloed:kwantitatief:
pl-PL Polish (Poland) Hemoglobina A1c/hemoglobina całkowita:frakcja masowa:punkt w czasie:krew:ilościowy:
Synonyms: Hemoglobina A1c/Hemoglobina całkowita
pt-BR Portuguese (Brazil) Hemoglobina A1c/
Synonyms: ; Hgb A1c; Glycohemogolobin; Glycohaemogolobin; GHb; HA1c; HBA1c; Glycated hemoglobin; Glycosylated hemoglobin; Hb; Haemoglobin; Substance fraction; Percent; Point in time; Random; Blood; WB; Whole blood; Quantitative; QNT; Quant; Quan; Tot; Totl; HEMATOLOGY/CELL COUNTS; HEMATOLOGY/CELL COUNTS
ru-RU Russian (Russian Federation) Гемоглобин А1с/Гемоглобин.общий:МассДол:ТчкВрм:Кр:Колич:
Synonyms: Количественный Кровь Массовая доля Точка во времени;Момент
tr-TR Turkish (Turkey) Hemoglobin A1c/ütlFr:Zmlı:Kan:Kant:
uk-UA Ukrainian (Ukraine) Гемоглобін A1c/Гемоглобін загальний:Масова Фракція:МоментЧасу:Кров:Кількісно:
Synonyms: Blood; Chemistry; Endocrine; Endocrinology; GHb; Glycated hemoglobin; Glycohaemogolobin; Glycohemogolobin; Glycosylated hemoglobin; HA1c; Haemoglobin; Hb; HbA1c; Hgb; Hgb A1c; Mass fraction; Percent; Point in time; QNT; Quan; Quant; Quantitative; Random; Tot; Totl; WB; Whole blood
zh-CN Chinese (China) 血红蛋白 A1c/血红蛋白.总计:质量分数:时间点:全血:定量型:
Synonyms: GHb;HA1c;HBA1c;Hgb A1c;糖化血红蛋白;糖基化血红蛋白;血红蛋白 A1c (糖化血红蛋白) MFr 全体数量 全部 共计 化学;化学检验项目;化学检验项目类;化学类;化学试验;非刺激耐受型化学检验项目;非刺激耐受型化学检验项目类;非刺激耐受型化学试验;非刺激耐受型化学试验类 可用数量表示的;定量性;数值型;数量型;连续数值型标尺 总 总和 总数 总血红蛋白 总量 总额 时刻;随机;随意;瞬间 氧血红蛋白;血红朊;血红素;血色素 汇总 血;血液

Example Units

Unit Source
% Example UCUM Units
% eCHN

LOINC Terminology Service (API) using HL7® FHIR® Get Info

CodeSystem lookup$lookup?system=