Many people think of Social Security as a program that benefits retired and disabled workers, but it can also be a huge help to their family members. Spousal benefits are available to the partners of qualifying workers even if the spouse never worked. But these benefits aren't always well understood.

If you're married and hope to claim Social Security someday, here are a few key spousal benefit rules you need to be aware of now.

A smiling couple looking at each other in kitchen.

Image source: Getty Images.

1. How much a spousal benefit is

A spousal benefit is worth up to 50% of the worker's benefit at their full retirement age (FRA). FRA is based on your birth year. It's 67 for most people today, though some older workers have an FRA as young as 66.

To give you an idea of how this works, consider a worker who qualifies for a $2,000 monthly benefit at their FRA of 67. Their spouse's maximum spousal benefit would be half of this amount, or $1,000 per month.

But it's possible the spouse could receive even less if they claim under their own FRA. This shrinks the size of their benefit checks by up to 35%. Returning to the previous example, if the maximum spousal benefit was $1,000 for an adult with an FRA of 67, they'd only get $650 per month if they signed up right away at 62.

The worker claiming early will not reduce the spouse's maximum spousal benefit. However, it could reduce the survivor's benefit the spouse is entitled to if the worker passes away.

2. Qualifying isn't a guarantee you'll receive a spousal benefit

Technically, the only requirement you have to meet to claim a spousal Social Security benefit is being married to a qualifying worker. But there are many individuals who are dually eligible for Social Security -- that is, they qualify for a spousal benefit as well as a benefit based on their own work history.

The Social Security Administration gives these individuals the larger of the two benefits. So if the worker's own benefit amount is larger than the spousal benefit, they will receive their own benefit instead. They will not receive both benefits.

If the spousal benefit is larger than the worker's benefit, the Social Security Administration first pays out the worker's own benefit. Then, it pays a portion of the spousal benefit so that the total amount equals the full spousal benefit they're eligible for.

For example, if a worker's own benefit is $1,000 and their spousal benefit is $1,500, the Social Security Administration would pay the worker's $1,000 benefit, plus a $500 spousal benefit on top of it for a total monthly check of $1,500.

3. Ex-spouses may be able to claim benefits, too

The Social Security Administration also pays spousal benefits to the ex-spouses of qualifying workers under certain conditions. In order to qualify for these, the couple must have been married for at least 10 years before divorcing. The ex-spouse may not have remarried, though it's OK if the worker has. And of course, the ex-spouse must be at least 62 before claiming.

If the worker is already claiming benefits themselves, the ex-spouse can sign up as soon as they want. But if the worker isn't claiming yet, the ex-spouse must wait until the couple has been divorced for at least two years before applying. This is different from currently married couples where the spouse cannot claim a spousal benefit until the worker applies.

A spousal benefit can make a significant difference to a household's monthly budget, so it's important to be strategic about when both partners will apply for benefits. Talk it over and decide when each person will sign up so you can estimate your monthly benefit amounts and plan your retirement budget.