Why was the agreement never implemented?

It was never transmitted by the President to Congress for the review period that US law requires before such an agreement can take effect. It has remained signed but dormant since 2004; a resolution disapproving it (H.Res. 18) was introduced in the House in 2007, reflecting the opposition it drew.

Do my Mexican weeks count toward US Social Security?

No. Without an agreement in force, SSA tests you on your US record alone. You need 40 US credits — about ten years of covered US work — and Mexican contributions cannot bridge any part of that gap.

Do my US credits count toward a Mexican pension?

No. IMSS tests you on your Mexican weeks alone. The 2026 requirement is 875 weeks, roughly seventeen years, rising by 25 weeks a year to 1,000 weeks in 2031.

Do I lose my AFORE savings if I do not reach the weeks threshold?

No. The AFORE account is your own property. Short of the weeks threshold you do not receive a monthly IMSS pension, but the balance is paid out as a lump sum — a retiro en una sola exhibición. What you lose is the monthly pension and the pensión garantizada, not the savings.

Does the US–Mexico tax treaty help with social security?

No. An income-tax treaty and a totalization agreement are different instruments. The tax treaty does nothing for pension eligibility and does not exempt you from contributing to both social-security systems.

Will a Mexican pension reduce my US Social Security?

Not since 2025. The Social Security Fairness Act repealed the Windfall Elimination Provision and the Government Pension Offset, so a foreign pension no longer triggers a reduction of a US benefit.

Totalization · US–Mexico

There is no US–Mexico totalization agreement

An agreement was signed on 29 June 2004. It has never entered into force, and more than twenty years later Mexico is still absent from the list of agreements the United States actually operates. Your US and Mexican periods therefore do not combine in either direction. This page explains what that costs you, why the situation persists, and what is still worth doing.

Is there a US–Mexico totalization agreement?

No — not one that is in force.

An agreement was signed on 29 June 2004, but it has never entered into force, and Mexico does not appear on SSA's list of agreements the United States actually operates. Signed and in force are different things, and only the second one affects your pension.

What that means for your record

Your Mexican periods cannot count toward the US qualifying threshold. The United States tests you on your US record alone.
Your US periods cannot count toward Mexico's qualifying threshold either. The agreement would have been reciprocal; its absence is reciprocal too.
Neither set of contributions is lost or refunded. Each country still owes you whatever its own rules say your own record earns — which may be nothing, if you are short of that country's minimum.
There is no certificate of coverage, so nothing exempts you from contributing to both systems at once while working across the corridor.

See what each country pays on its own record

Estimates only — not financial, tax, or legal advice. Verify with official institutions.

What "no agreement" means for a US–Mexico career

Signed is not the same as in force

This is the distinction the entire page turns on, and it is the reason so much confusing material exists about this corridor. A totalization agreement becomes operative only after it has been signed, approved on both sides, and formally brought into force. The US–Mexico agreement completed the first step on 29 June 2004 and has never completed the last one.

On the American side an agreement must be transmitted by the President to Congress, which then has a review period before it can take effect. That transmission never happened for Mexico. The agreement has sat signed and dormant ever since, through successive administrations, and it has drawn opposition along the way — a resolution disapproving it (H.Res. 18) was introduced in the 110th Congress in 2007.

So when you read that the United States and Mexico 'have an agreement', that is technically true of a piece of paper and false of anything that affects your pension. What matters for a claimant is the list of agreements in force, and Mexico is not on it.

What this actually costs you

The practical consequence is a hard one, and it is worth stating without softening. Your Mexican weeks cannot help you reach the American 40-credit threshold, and your American credits cannot help you reach Mexico's weeks threshold. Each country tests you on its own record alone, as though the other half of your working life had not happened.

For a split career this is the worst of the available outcomes. Someone with eight years of covered US work and fifteen years of IMSS contributions would, in an agreement country, almost certainly qualify for a partial US benefit. Here they qualify for nothing from the United States — eight years is up to 32 credits against a threshold of 40, and there is no mechanism to bridge the gap. The eight years are not refunded and do not transfer; they simply pay nothing.

It cuts the other way too. American periods do not count toward the Mexican weeks requirement, which in 2026 stands at 875 weeks — about seventeen years — and is rising by 25 weeks every year until it reaches 1,000 weeks in 2031. Someone who spent the middle of their career in the United States can find themselves short at both ends.

The one thing that is not affected: your AFORE

Here is the part that genuinely softens the picture, and it is specific to Mexico. Since the 1997 reform, a Mexican pension under Ley 97 is funded by an individual retirement account — your AFORE. That account is your property. The money in it is yours whether or not a totalization agreement exists, because it was never a pooled entitlement that an agreement would need to unlock.

This changes what the missing agreement costs. In a country with a pay-as-you-go public pension, failing the qualifying threshold can mean your contributions produce nothing. In Mexico, failing the weeks threshold means you do not get a monthly IMSS pension — but the AFORE balance is still paid out to you, as a lump sum, in what is called a retiro en una sola exhibición. That is materially worse than a pension and materially better than nothing.

The weeks threshold is what buys the monthly pension and, with it, access to the pensión garantizada — the guaranteed minimum for those who qualify, which in 2026 runs from about 3,540 to 11,128 pesos a month depending on age, weeks contributed and average salary. Miss the threshold and you lose the guarantee, not the savings.

Check which Mexican system you are actually in

Before anything else, establish whether you fall under Ley 97 or Ley 73, because the two are entirely different pensions and the answer changes what you should do.

If you first contributed to IMSS before 1 July 1997, you may elect Ley 73 — the pre-reform defined-benefit system, which pays a calculated pension based on your salary and years rather than an account balance, and which is materially more generous for most people who qualify. Anyone who started contributing after that date is under Ley 97 and the AFORE rules above.

This matters disproportionately for cross-border workers, because a career that began in Mexico in the early 1990s, moved to the United States, and returned may well carry a pre-1997 IMSS registration that its owner has forgotten about. It is worth checking your Número de Seguridad Social history with IMSS rather than assuming.

What you can still do

First, get to 40 US credits under your own steam if you are anywhere near. With no agreement available, that threshold is the whole game on the American side, and there is no partial credit for being close. If you are at 32 credits, two more years of covered US work — including self-employment, which counts — turns nothing into a lifetime benefit. Very few financial decisions have that shape, and people miss it because they assume their Mexican years are doing something.

Second, find out exactly where you stand rather than estimating. Your Social Security Statement gives your real US credit total; IMSS and your AFORE statement give your real weeks and balance. Both are free and both are more accurate than any calculator, including this one.

Third, understand that a tax treaty is not a totalization agreement. The United States and Mexico do have an income-tax treaty, and it does nothing for social-security eligibility. Material conflating the two is common and is a reliable sign that the source has not understood the question.

Fourth, budget for contributing to both systems at once if you are working across the border. The other half of a totalization agreement is the part that stops the same earnings being charged twice, and without one there is no certificate of coverage to exempt you. An American self-employed in Mexico can face US self-employment tax and IMSS contributions on the same income, with no relief mechanism.

Could this change?

It could, and it is the reason to check the position rather than treat it as settled. The agreement exists in signed form, which means bringing it into force requires no fresh negotiation — only the political decision to transmit it. That is a much lower bar than starting from nothing, and it is why the file has never quite closed.

It is also why the honest answer is 'not currently' rather than 'never'. Romania is the useful comparison: its agreement was signed in March 2023 and entered into force on 1 September 2026, becoming the thirty-first. Agreements do move. This one has not moved in over twenty years, and the Government Accountability Office's 2003 review of the proposal — which flagged unusual difficulties in estimating its cost and verifying Mexican earnings records — remains the clearest account of why.

Plan on the basis that there is no agreement, because there is not. But if you are years away from claiming, it is worth re-checking rather than assuming the answer is permanent.

WEP and GPO were repealed in 2025

One piece of good news that does apply here. Older articles warn that a foreign pension reduces your US benefit through the Windfall Elimination Provision, or that the Government Pension Offset cuts a spousal benefit. The Social Security Fairness Act repealed both in 2025. If you do qualify for a US benefit on your own record, a Mexican pension no longer reduces it — and this estimator applies no such reduction.

Common questions

Is there a totalization agreement between the United States and Mexico?: No. An agreement was signed on 29 June 2004 but has never entered into force, and Mexico does not appear on SSA's list of agreements in force. US and Mexican insurance periods do not combine in either direction.
Why was the agreement never implemented?: It was never transmitted by the President to Congress for the review period that US law requires before such an agreement can take effect. It has remained signed but dormant since 2004; a resolution disapproving it (H.Res. 18) was introduced in the House in 2007, reflecting the opposition it drew.
Do my Mexican weeks count toward US Social Security?: No. Without an agreement in force, SSA tests you on your US record alone. You need 40 US credits — about ten years of covered US work — and Mexican contributions cannot bridge any part of that gap.
Do my US credits count toward a Mexican pension?: No. IMSS tests you on your Mexican weeks alone. The 2026 requirement is 875 weeks, roughly seventeen years, rising by 25 weeks a year to 1,000 weeks in 2031.
Do I lose my AFORE savings if I do not reach the weeks threshold?: No. The AFORE account is your own property. Short of the weeks threshold you do not receive a monthly IMSS pension, but the balance is paid out as a lump sum — a retiro en una sola exhibición. What you lose is the monthly pension and the pensión garantizada, not the savings.
Does the US–Mexico tax treaty help with social security?: No. An income-tax treaty and a totalization agreement are different instruments. The tax treaty does nothing for pension eligibility and does not exempt you from contributing to both social-security systems.
Will a Mexican pension reduce my US Social Security?: Not since 2025. The Social Security Fairness Act repealed the Windfall Elimination Provision and the Government Pension Offset, so a foreign pension no longer triggers a reduction of a US benefit.

Your US years are only part of the picture

This page answers one question: whether US and Mexican periods combine. They do not — but each country still owes you whatever its own record earns. The estimator takes every country you have worked or lived in and produces one consolidated monthly figure, with the per-country breakdown, the aggregation logic, the assumptions and the official sources behind it.

Get your full cross-border pension estimate

Sources

Estimates only — not financial, tax, or legal advice. Verify with official institutions. The authority on your US record is SSA; the authority on your Mexican record is Mexico's own pension institution.