How much more OAS do I get by waiting until 70?

OAS rises 0.6% for every month you defer past 65, up to 36% more at age 70 — permanently, and indexed to inflation. Unlike CPP, there's no option to start OAS before 65 and no benefit to waiting past 70.

Should I defer OAS if I'll face the clawback?

Often not. Deferring gives you a larger OAS, but if your income will sit above the recovery-tax threshold, a bigger OAS just gets clawed back faster. When clawback is likely, the deferral decision and your drawdown plan should be looked at together.

When should you take OAS — at 65 or defer to 70?

Old Age Security gets less attention than CPP, but it comes with the same quiet decision: start it at 65, or wait for a bigger cheque. Deferring OAS raises it by 0.6% a month, up to 36% more at age 70, for life and indexed to inflation. Whether that's worth it depends on your health, your income, and one wrinkle that doesn't apply to CPP — the clawback.

OAS isn't the same animal as CPP

A few differences change the decision:

It's based on residency, not contributions. Full OAS takes 40 years in Canada after age 18. Fewer years means a partial pension.
You can't take it early. CPP can start at 60; OAS cannot start before 65.
The deferral boost is smaller. OAS grows 0.6%/month, versus 0.7%/month for CPP — so the reward for waiting is a bit less generous.
There's a bump at 75. OAS automatically rises about 10% once you turn 75.

The breakeven is later than CPP's

Because the deferral increase is smaller, the breakeven age for waiting is further out. Delaying from 65 to 70 means giving up five years of payments in exchange for 36% more each year afterward — which typically doesn't pay off until your mid-80s. If longevity runs in your family and you can cover the gap from savings, that can still be a good trade. If not, taking OAS at 65 is perfectly reasonable.

Watch the clawback before you defer

Here's where it gets specifically Canadian. OAS is subject to a recovery tax — the "clawback" — that takes 15¢ of every dollar back once your net income climbs above roughly $90,000. Deferring to 70 gives you a larger OAS, but if your income in your 70s will already sit in clawback territory, that larger benefit just gets recovered faster. In that case the smart move is often to take OAS at 65 and manage income instead — with TFSA withdrawals and pension splitting. You can see how the clawback bites at different income levels with the OAS clawback calculator.

When deferral makes sense

Waiting to 70 tends to win when you're in good health, expect a long life, have savings or a delayed CPP bridge to live on in the meantime, and your income will stay below the clawback line. Take it at 65 if you need the money, your health or family history points to a shorter horizon, or a bigger OAS would simply be clawed back. Model it against your own income and see which leaves more in your pocket.