This guide explains how the Canada-US social security agreement fits together for people who have worked in both countries. It is general information, not advice about your file. Totalization outcomes depend on the exact months you worked and lived in each country, and the agencies compute them from their records, not from your memory. Confirm your own numbers with Service Canada and the Social Security Administration before making decisions that depend on them.
By Lucas Wennersten, CFP® (US & Canada), CFA · 13-minute read
Most people who have worked on both sides of the border assume one of two things about their government pensions, and both are wrong. The first is that the years they spent paying into the Canada Pension Plan somehow add to their US Social Security cheque. The second is that if they didn’t work long enough in one country to qualify, that country owes them nothing. The Canada-US Totalization Agreement sits precisely between those two mistakes: it lets each country count your time in the other to decide whether you qualify, while each still pays only for the years you actually spent in its system.
That distinction, qualification versus amount, is the whole agreement. Once you hold it clearly, every rule below follows from it. This guide walks through what the agreement does for a split career, the one place it matters most (Old Age Security, not CPP), how the pro-rated US benefit is computed, how to avoid paying into both systems while you’re working, and the tax treatment once the cheques start. It is a companion to our broader look at Social Security vs. CPP and OAS, which covers how the three programs differ; this piece is only about how they interact when your work history is split.
First, the honest answer: it fills gaps, it doesn’t add money
The agreement has been in force since August 1, 1984, and it does three things. It prevents you from being covered, and taxed, by both systems on the same earnings. It lets each country add your periods of coverage in the other to meet its own minimum qualifying requirement. And it lets you apply for both countries’ benefits through either country’s agency.
What it never does is transfer contributions or increase the benefit either country pays for your own coverage. A Canadian who worked eight years in the United States does not get eight years added to their CPP. An American who lived six years in Canada does not get a bigger OAS pension because of thirty years of US payroll taxes. Every dollar you receive is still earned inside the system that pays it. If you came to this guide hoping the agreement would raise a benefit you already qualify for, it won’t, and you can stop here with a clear conscience.
If you came because you’re short of a minimum somewhere, keep reading, because that is exactly the problem it solves.
alt=”Canada-US totalization agreement side by side: foreign periods count toward eligibility but not toward the benefit amount” width=”1200″ height=”630″ />Where the minimums bite
Each program has a different threshold, so the agreement matters far more for some benefits than others.
US Social Security retirement requires 40 credits, roughly ten years of covered work. Under the agreement, if you have at least six US credits (about a year and a half), the Social Security Administration will count your Canadian coverage, both CPP or QPP contribution years and periods of OAS residence, to reach 40. Fewer than six US credits and the agreement cannot help you on the US side at all. The reverse is also true: if you already have 40 US credits on your own, the SSA will not add Canadian coverage, because there is nothing left to qualify for. That six-credit floor is the single most important number in this guide for Canadians who did a short US stint.
Canada Pension Plan retirement needs only one valid contribution to qualify, so the agreement almost never matters for a CPP retirement pension. It does matter for CPP disability and survivor benefits, which have minimum contributory periods that US coverage can help you satisfy.
Old Age Security is where Canadians and Americans alike get caught. OAS is based on residence, not contributions. You need ten years of residence in Canada after age 18 to receive it while living in Canada, and twenty years to have it paid to you outside Canada. Under the agreement, your US quarters of coverage earned after 1951 and after age 18 count toward those thresholds, with each US quarter treated as three months of Canadian residence, provided you have at least one year of Canadian residence after 18 to anchor the claim. Without the twenty years (on your own or totalized), OAS stops six months after you leave Canada. The catch, and it is a large one, is that the amount is still one-fortieth of the full pension for each year you actually lived in Canada after 18. The agreement can get an American with six Canadian years across the ten-year line, but the pension they receive is 6/40ths of full OAS, not a full pension.
That asymmetry, US periods count for OAS eligibility but not OAS amount, is the mechanism people find hardest to believe. It is also the one that shows up most often in our planning conversations.
Same work history, two outcomes
Consider Maria, a Canadian who worked in Chicago for eight years in her thirties (32 US credits) and then spent twenty-five years in Toronto contributing to CPP. Without the agreement, her 32 credits fall short of 40 and the US owes her nothing. With it, the SSA counts her Canadian years to reach the threshold and she qualifies for a US retirement benefit.
How much? This is where people who know Social Security well tend to object, because a US benefit is supposed to be based on your own earnings, and it is. The Social Security Administration’s own procedure has four steps. First, it takes Maria’s actual US earnings for each of her eight years and divides them by the national average wage for that year, which fixes where she sat relative to the average worker. Second, it builds a theoretical earnings record by assuming she had earned at that same relative level for a full 35-year career. Third, it runs that record through the ordinary benefit formula to get a theoretical monthly amount, the benefit a full career at her earnings level would have paid. Fourth, it pro-rates that amount by the share of a full career she actually spent in the US: her 32 credits are 96 months, divided by the 420 months in a standard computation, or about 23 percent.
If the theoretical monthly figure came to $1,000, her totalized benefit would be about $230 a month. The dollar amounts are illustrative; the fraction is not. Her own earnings set the level, and her time in the US sets the share. She gets something real for years that would otherwise have paid nothing, and it is proportionate to her US career, no more.
Now consider David, an American who moved to Vancouver at 58, lived there six years, then retired back to Arizona. On his own, six years of Canadian residence is below both the ten-year OAS threshold and the twenty-year threshold for payment abroad. Under the agreement, his decades of US quarters count toward both, so he qualifies for OAS and can be paid in Arizona. His pension is 6/40ths of the full amount. His CPP, if he contributed even once while working in Vancouver, is payable anywhere without the agreement’s help.
Neither of these people gets a windfall. Both get a benefit they would otherwise have forfeited. That is the agreement working as designed.
Working across the border: don’t pay twice
The second half of the agreement is about coverage while you are still working, and it saves real money for people who get it right.
The default rule is that you are covered by the system of the country where the work is performed. The agreement carves out two exceptions. A detached worker, an employee sent by their employer to the other country for a temporary assignment expected to last five years or less, stays in their home country’s system and is exempt from the host country’s payroll tax. A self-employed person is covered by the country where they reside, regardless of where the clients are.
The exemption is not automatic. It runs on a certificate of coverage. A US employer sending someone to Canada requests it from the Social Security Administration; a Canadian employer or self-employed person whose work will stay under CPP requests it from the Canada Revenue Agency using Form CPT56. Self-employed workers attach a copy of the certificate to their US tax return every year as proof of the exemption. The certificate is what you show the host country’s authorities to prove you are exempt. Without it, the host country will expect contributions, and unwinding double payments after the fact is slow and not always successful.
alt=”Process flow for obtaining a certificate of coverage under the Canada-US totalization agreement before a cross-border assignment” width=”1200″ height=”630″ />Two planning points fall out of this. First, if you are near a minimum in one system, staying in it during a short assignment may be exactly what you want, and the certificate gives you that choice. Second, if you have already crossed the 40-credit line in the US and are paying into CPP with no prospect of reaching a meaningful CPP pension, the coverage rules and Canada’s election to stop contributing to CPP at 65 are worth reading together.
What the WEP repeal changed, and what it didn’t
Until 2025, Canadians drawing both CPP and US Social Security were often shocked by the Windfall Elimination Provision, which cut the US benefit because CPP was a pension from non-covered work. The Social Security Fairness Act, signed in January 2025, repealed the WEP for benefits payable after December 2023. CPP no longer reduces your Social Security. We cover the details, including retroactive payments, in our guide to the WEP repeal for Canadians.
It is worth being precise about what the repeal did not touch. It did not change the agreement. Totalized benefits are still pro-rated by the same formula. The six-credit floor is unchanged. OAS is still one-fortieth per year. The repeal removed a penalty that sat on top of the agreement; it did not make the agreement more generous.
How the benefits are taxed once they start
The agreement decides who pays you. The Canada-United States Tax Convention decides who taxes it, and the rule is simpler than most people expect.
Social security benefits from either country are taxable only in the country where you live when you receive them. A Canadian resident drawing US Social Security reports it in Canada, and 15 percent of it is excluded from Canadian income, so only 85 percent is taxed. The United States does not tax it. A US resident drawing CPP or OAS reports those payments in the United States as if they were US Social Security, and Canada does not withhold. This is one of the few places where the two systems line up cleanly, and it is a reason the drawdown order for people retiring in Canada as an American can look quite different from a domestic plan.
One caution for people who end up receiving OAS in Canada: the agreement can get you across the eligibility line, but the OAS recovery tax, commonly called the clawback, applies to your worldwide income once you are a Canadian resident. If you have substantial US retirement income, run the numbers through our OAS clawback calculator before assuming the pension you qualified for is the pension you will keep.
Applying for benefits under the agreement
You can apply for both countries’ benefits at either agency, and the one you file with will forward the claim. In practice, filing with each agency directly is faster. Service Canada’s international operations unit handles agreement claims for Canada Pension Plan (CPP) and Old Age Security (OAS); the SSA’s international operations office handles US claims from people living in Canada.
The sequencing that avoids most delays:
- Twelve months before your planned start date, request your CPP Statement of Contributions from Service Canada and your Social Security Statement from the SSA. Check both against your own records. Missing years cannot be fixed quickly.
- Assemble proof of residence periods in Canada (leases, tax returns, employment records). OAS is a residence test, and the burden is on you.
- If you have fewer than 40 US credits, tell the SSA explicitly that you are applying under the Canada-US agreement. Ordinary retirement applications are sometimes processed without the totalization step. If you live in the United States, Canadian benefits are claimed through any US Social Security office on Form CDN-USA 1.
- If you will live outside Canada, confirm you meet the twenty-year OAS threshold on your own or with US periods counted, and tell Service Canada where you want payment.
- File six months before the start date. Agreement claims move between two bureaucracies and routinely take longer than domestic ones.
- Keep copies of every certificate of coverage you ever held. They are the only proof that a gap in one country’s record was intentional.
alt=”Key stat: six US Social Security credits is the minimum for the Canada-US totalization agreement to combine Canadian coverage” width=”1200″ height=”630″ />Six mistakes we see most
Assuming CPP adds to Social Security. It counts toward whether you qualify. It never raises the US benefit computed on your US earnings.
Leaving the US with fewer than six credits. One more year of covered work before you go, or a short covered assignment later, can be the difference between a lifetime pro-rated benefit and nothing.
Expecting full OAS from a short Canadian stay. The agreement gets you to the eligibility line. The pension is still one-fortieth per year of actual residence.
Paying into both systems on a detached assignment. No certificate of coverage means the host country expects contributions. Get the certificate before the plane leaves.
Applying to one agency and assuming the other is handled. Forwarding happens, but slowly and not always completely. File with both.
Ignoring the tax side. The treaty rule is favourable but only if the benefit is reported in the right country. US Social Security reported in the United States by a Canadian resident is a common and expensive filing error.
Frequently asked questions
What does the Canada-US totalization agreement actually do?
It lets each country count your periods of coverage in the other to meet its own minimum qualifying requirement for benefits, and it prevents you from paying into both systems on the same earnings while you work abroad. It does not transfer contributions or increase the benefit either country pays for your own coverage.
How many US credits do I need for the agreement to help?
At least six. With six or more US credits, the Social Security Administration will count your Canadian CPP contributions and OAS residence toward the 40 credits needed for retirement benefits. With fewer than six, Canadian coverage cannot be added.
Does my CPP increase my Social Security payment?
No. Canadian coverage helps you reach the 40-credit threshold. Once you qualify, the SSA computes the benefit a full career at your own US earnings level would have paid, then pro-rates it by the share of a 35-year career you actually spent in US-covered work. Your earnings set the level; your US time sets the share.
Can an American who lived in Canada for a few years get OAS?
Possibly. OAS normally requires ten years of Canadian residence after age 18, or twenty to be paid outside Canada. Under the agreement, US quarters of coverage count toward those thresholds, as long as you have at least one year of Canadian residence after 18. The pension amount, however, is still one-fortieth of the full OAS for each year of actual Canadian residence.
What is a certificate of coverage and who issues it?
It is the document that proves a worker on a temporary cross-border assignment remains covered by their home country’s system and is exempt from the host country’s payroll tax. US employers request it from the Social Security Administration; Canadian employers and self-employed workers request it from the Canada Revenue Agency on Form CPT56. It should be in hand before the assignment begins.
Is the WEP still reducing Social Security for people with CPP?
No. The Social Security Fairness Act repealed the Windfall Elimination Provision for benefits payable after December 2023. CPP no longer reduces US Social Security. The repeal did not change how totalized benefits are calculated.
How is US Social Security taxed if I live in Canada?
Under the Canada-US tax treaty, it is taxable only in Canada, and 15 percent of the benefit is excluded from Canadian income, so 85 percent is taxed. The United States does not tax it. CPP and OAS received by a US resident are taxable only in the United States, treated as if they were US Social Security.
Should I apply in Canada or the United States?
You may apply at either agency and the claim will be forwarded, but filing directly with each is usually faster. Tell the SSA explicitly that you are applying under the Canada-US agreement if you have fewer than 40 US credits, and file about six months before your intended start date.
Does the agreement cover self-employed people?
Yes. A self-employed person is covered by the social security system of the country where they reside, regardless of where their clients are located. This avoids double contributions without needing a certificate of coverage, though documenting residence clearly still matters.
Can survivor or disability benefits be totalized too?
Yes. CPP disability and survivor benefits have minimum contributory requirements that US coverage can help satisfy, and US disability and survivor benefits can likewise use Canadian coverage to meet their insured-status tests. The same six-credit floor applies on the US side.
Related reading
- The WEP Repeal: What Canadians Collecting US Social Security Need to Know in 2026 — what the repeal restored, and the retroactive payments
- Social Security vs. CPP & OAS: Cross-Border Retirement Insights — how the three programs differ before they interact
- Election to Stop Contributing to CPP in Canada : Rules, Process, and Impact on Benefits — when continuing to contribute stops making sense
- Retiring in Canada as an American: Social Security, RRSPs, RMDs, and Getting the Income Right — sequencing income once the pensions start
- Social Security: Benefits for Non-Citizen, Non-Resident Spouses — the spousal rules the agreement does not change
A split career produces split pensions, and the agreement is the set of rules that decides what each half is worth. Getting the sequence right, from the certificate of coverage during your working years to the order you file in retirement, is the kind of decision our cross-border retirement planning work is built around.
If you have worked in both countries and are not sure what each one owes you, that is a question with a specific answer. Book a complimentary consultation and we will pull both statements, map your coverage periods, and show you what the agreement does and does not do for your file.
