HbA1c and fasting glucose (diabetes screening)

Pick Ordered or Not ordered to see the note.

Indicated when

• —Risk factors for type 2 diabetes, such as overweight or obesity, hypertension, dyslipidemia, a family history of diabetes, a history of gestational diabetes, or membership in a higher-risk population, where screening with A1C and/or fasting plasma glucose every 3 years (or more often with higher risk) is recommended [7]
• —The Canadian Task Force advises against routine screening of adults at low risk. For adults at high risk on a validated risk calculator (e.g. CANRISK or FINDRISC), it recommends A1C screening every 3 to 5 years, and more often at very high risk [9]
• —Symptoms of hyperglycemia, such as increased thirst, frequent urination, or unexplained weight loss
• —As part of an initial work-up for persistent tiredness or suspected insulin resistance, alongside the clinical picture

Not indicated when

• —Routine A1C or fasting glucose testing every year, or more often than every 3 years, in a low-risk adult with no diabetes risk factors, ahead of the interval the guideline supports [7, 8]

Why not

Testing more frequently than the recommended interval in a low-risk adult increases the chance of an isolated borderline result that does not change management sooner than the guideline-directed interval would, while adding cost [8].

Better first step

Assess diabetes risk factors, or use a validated risk tool, to decide whether and how often to screen, then follow the Diabetes Canada-recommended interval of every 3 years for at-risk adults, rather than including A1C or glucose in every annual panel regardless of risk [7].

Typical ND rationale

An ND may include HbA1c and fasting glucose in a wellness panel, reasoning that catching prediabetes or early diabetes before symptoms develop allows for earlier lifestyle intervention and better long-term outcomes.

Ontario coverage & CONO orderability

OHIP status

insured

Glycosylated hemoglobin/HbA1c (L093), glucose quantitative (L111), and glucose tolerance test (L104, or L103 in pregnancy) are each listed by name in the 2026 Schedule of Benefits for Laboratory Services, insured when ordered by a physician, midwife, or NP who has clinically assessed the patient. ND-ordered testing is not insured and is billed privately (Reg. 552 s.22(1); SOB-LS 2026 preamble).

CONO orderable

Yes — CONO list #75, #72, #73

CONO list item 75, blood: 'Hemoglobin – A1C'; item 72, blood: 'Glucose, quantitative'; item 73, blood: 'Glucose Tolerance Test.'

Linked conditions

• diabetes ↗
• Insulin resistance ↗
• tired ↗

Counselling script

“Given your risk factors, checking your blood sugar with an A1C or fasting glucose every few years is genuinely worthwhile, since catching prediabetes early gives us the best chance to change course with lifestyle changes, so let's do that today. If you don't have risk factors like these, testing every single year isn't necessary, since it's very unlikely to change anything sooner than testing on the recommended few-year interval would. I'll keep track of when you're next due.”

Revisit if

• —New risk factors for type 2 diabetes develop (weight gain, new hypertension, new dyslipidemia)
• —Symptoms of hyperglycemia develop
• —Due for the next guideline-recommended screening interval

References

1. [1]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkGlycosylated hemoglobin/HbA1c (L093) is listed by name in the 2026 OHIP Schedule of Benefits for Laboratory Services
2. [2]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkGlucose, quantitative (L111) is listed by name in the 2026 OHIP Schedule
3. [3]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkGlucose tolerance test (L104) is listed by name in the 2026 OHIP Schedule
4. [4]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkCommunity lab tests are insured only when ordered under the Schedule by an authorized prescriber
5. [5]Government of Ontario (e-Laws) (2026). Health Insurance Act, R.R.O. 1990, Reg. 552: General, s. 22 (insured laboratory services). linkA lab test is insured only when ordered by a physician, midwife, or NP who has clinically assessed the patient
6. [6]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkTests ordered by anyone other than an authorized provider, including NDs, are not insured services
7. [7]Diabetes Canada (2018). Diabetes Canada Clinical Practice Guidelines: Screening for Diabetes in Adults. linkScreen for type 2 diabetes using fasting plasma glucose and/or A1C every 3 years in adults with risk factors
8. [8]Canadian Society for Medical Laboratory Science / Choosing Wisely Canada (2025). Medical Laboratory Science: Fourteen Tests and Treatments to Question. linkDon't support repeat test ordering at a frequency not backed by evidence
9. [9]Canadian Task Force on Preventive Health Care (2012). Recommendations on screening for type 2 diabetes in adults. linkolder guidelineCTFPHC 2012: no routine screening at low risk; risk-calculator-based A1C screening every 3-5 years at high risk (weak recommendation, low-quality evidence)