“When should I get my first mammogram in Ontario?” is one of the most common questions we hear at the front desk — and the answer recently changed in a way many Ontarians don’t yet know about. If you’ve been putting off asking because you assumed you weren’t eligible yet, it’s worth a second look, since the rules shifted meaningfully in the last couple of years.

First Mammogram in Ontario: The Eligibility Age Was Recently Lowered

As of October 2024, the Ontario Breast Screening Program (OBSP) lowered its self-referral age from 50 to 40. That means women aged 40 and older can now book a publicly funded screening mammogram directly, without needing a doctor’s referral, once every two years — a significant change from the previous system, where average-risk screening didn’t typically begin until age 50.

What this means for you, by age group

• Ages 40–74, average risk: Eligible to self-refer for a free screening mammogram every 2 years through OBSP, with no referral required
• Ages 30–69, high risk (based on strong family history, a known genetic mutation like BRCA1/2, or previous chest radiation): Eligible for annual screening with both mammography and MRI, with a doctor’s referral required
• Age 75+: Screening can continue, but it’s based on a conversation with your primary care provider, since the program doesn’t automatically recall patients in this age group the way it does for younger age brackets

Why the change matters

Earlier screening access is intended to catch breast cancer sooner, when treatment tends to be more effective and less invasive — and to help reduce disparities affecting groups of women who are statistically diagnosed with more aggressive cancers at a younger age. Lowering the self-referral age also removes a step (getting a doctor’s referral) that could otherwise delay someone from being screened, particularly for patients without a regular family physician.

Do you need a referral?

If you’re 40 or older and at average risk, no — you can self-refer directly to an OBSP site like Annex Medical Imaging. If you’re in the high-risk category, or if your doctor wants a diagnostic (not screening) mammogram to investigate a specific symptom like a lump or change, a referral is required regardless of your age.

What counts as “average risk” versus “high risk”?

Average risk generally describes someone with no personal history of breast cancer, no known genetic mutation, and no strong family history. High risk generally applies to people with a first-degree relative (parent, sibling, or child) diagnosed with breast cancer at a young age, multiple affected relatives, a known BRCA1/2 or other genetic mutation, or a history of chest radiation therapy, often for a prior cancer treatment. If you’re unsure which category you fall into, it’s worth discussing your family history with your doctor, since it affects both your starting age and how often you should be screened.

What if you’ve never had a mammogram before?

There’s no need to feel behind or embarrassed — many people delay their first screening for all sorts of reasons, from lack of awareness of the eligibility change to simple scheduling difficulty. The process for a first-time mammogram is the same regardless of when you start: self-refer if you’re 40+ and average risk, or get a referral if you fall into the high-risk category.

Breast awareness between screenings

Screening mammograms are performed on a set schedule (every two years for average risk), but that doesn’t mean paying attention to your breast health should wait until your next appointment. Being generally familiar with how your breasts normally look and feel makes it easier to notice a genuine change — like a new lump, dimpling, or nipple discharge — between scheduled screenings. If you notice something like this, it’s worth seeing your doctor promptly rather than waiting for your next scheduled OBSP appointment, since a new symptom calls for a diagnostic mammogram rather than routine screening.

What if you have dense breast tissue?

Some patients are told they have “dense” breast tissue after a mammogram, which simply describes the composition of breast tissue on imaging and is a common, normal finding — though dense tissue can make mammograms somewhat harder to interpret. If this applies to you, your doctor may discuss whether supplementary imaging, like ultrasound, makes sense as part of your individual screening plan going forward.

If you’ve been putting off asking because you assumed you weren’t eligible yet, it’s worth a second look.

Next steps

If you’re 40 or older and haven’t had a mammogram in the last two years, you’re likely eligible right now. For the full picture of how OBSP works — including what happens during your appointment and how results are communicated — see our complete guide to the Ontario Breast Screening Program. Annex Medical Imaging performs digital mammography for both OBSP screening and diagnostic follow-up at our Toronto location.