Since 2008, my team and I have been tracking the age at which Canadians expect to retire. The national average reached a high of 69 in 2011, followed by a drop to 67 a year later and then to 66 in 2013. There’s good reason for Canadians to plan to keep working past the traditional retirement age of 65. Many of us are doing work that we’re capable of continuing into our senior years. And we’re living longer, which makes it that much more difficult to save enough by your mid-60s to retire. Fully two-thirds who expect to keep working past 65 told us in 2013 that their decision is one of economic necessity (they “need to” rather than “want to”). That’s all from the Sun Life Canadian Unretirement Index.

But what if your plan to keep on working isn’t possible? Today, we released a new study that shows just how few retirement plans go, well, precisely according to plan.

Less than one-third (31%) of retired Canadians said they stopped working on the date they planned. That’s according to the 2014 edition of the Sun Life Canadian Health Index, a survey of 2,799 Canadians conducted by Ipsos Reid. The most common reason for this surprise exit from the workforce is personal health. Three in 10 (29%) retirees said they stopped working “for personal health or medical reasons.” A quarter said they left their jobs as a result of an employer decision. They either accepted an early retirement offer (15%) or were forced to retire by their employer (10%).

The survey question did not ask what age these respondents had to retire at because it is largely a non-issue. If you’re faced with a situation that triggers a retirement date earlier than the one you planned, it doesn’t matter what side of 65 you’re on. These days, early retirement can come just as easily at 69 as it can at 62 (perhaps more easily when health is taken into consideration). Someone close to me experienced exactly this when a stroke ended his career — very much prematurely in his opinion — at 72.

Canadians who find themselves in this situation face a kind of double whammy. Their income is cut off prematurely, precisely at the time they’re faced with new unforeseen healthcare expenses.

We asked all of our survey participants who have experienced a serious health event or accident what financial impact that experience had. The results are sobering. Four in 10 (42%) described some degree of financial hardship: 26% “some financial hardship” and 16% “significant financial hardship.” A quarter (25%) said the experience “reduced/depleted” their savings. Others had to put expenses on their credit cards, borrow money from friends and family, dip into their retirement savings or even sell their home.

The takeaway from all of this isn’t complicated. Planning to work past 65 is the right decision for many Canadians. But it’s a mistake to assume you’ll be able to work as long as you want. So a holistic financial plan that takes health expenses — and the potential for lost income as a result of a serious health event — into consideration is a must. Simply saving for retirement isn’t enough.