You may have grown up hearing the term widow's pension or even known those who have used this financial resource to help with living expenses after the death of a spouse. Today, about four million widows and widowers receive this monthly benefit.

Here's a brief guide to widow's pensions, who qualifies for them and how they work.

What Is a Widow's Pension?

Also known as widow or widower's insurance benefits or survivor's benefits, widow's pensions are federally funded monthly payments administered through the U.S. Social Security Administration. These payments go to the survivor of a deceased worker who earned enough work credits to qualify for this spousal benefit.

Any worker who has earned at least 40 credits — based on 10 years of work worth four credits each — qualifies for their surviving spouse to get the widow's pension. However, the exact number of credits needed depends on the person's age at their time of death. The younger they were, the fewer credits that are required.

How Was the Widow's Pension Created?

Congress established survivor benefits in 1939 through an amendment to the Social Security Act. The goal was to provide additional income to families of deceased workers who were eligible for Social Security benefits. That same year, another amendment established a program to pay Social Security benefits out to the spouses and minor children of retired workers. Together, these amendments marked the first expansion of Social Security benefits beyond retirement payments to workers.

Who Qualifies for Survivor's Social Security Benefits?

To receive the widow's pension, you must be at least age 60 (unless you have a qualifying disability) as well as the widow, widower or surviving nonmarital partner of a fully insured worker under Social Security rules. If you have a disability that begins within seven years of your spouse or partner's death, you can start receiving survivor's benefits at age 50. Married same-sex couples and those in nonmarital legal relationships such as civil unions and domestic partnerships became eligible for survivor's benefits in 2015.

You do not qualify for this benefit if you are entitled to an equal or higher Social Security benefit based on your own work history. If you qualify for both your own Social Security benefit and the survivor's benefit, you can switch to your benefit as early as age 62. If you remarry after age 60 (or age 50 if you are disabled), you are still eligible to receive the widow's pension.

The Social Security Administration's benefit eligibility screening tool can help you see whether you qualify for survivor's benefits.

How Can you Apply for Surviving Spouse Benefits?

Before you begin the application process, you must notify the Social Security Administration of your spouse's death. Funeral homes will typically take care of this step for you.

While the Social Security Administration's website provides information about how to apply, you cannot complete the process online. Instead, you must either call the agency's national toll-free service at 1-800-772-1213 (TTY 1-800-325-0778) or visit your local Social Security office.

Be prepared to answer questions and show documents to verify your eligibility. For example, you may be asked to provide proof of the death, your marriage certificate and your W-2 or self-employment tax forms.

Survivor's benefits can help relieve financial stress after the loss of a loved one, especially if it happens unexpectedly and in the early years of retirement. Understanding what a widow's pension is and how to access it puts financial support within reach for you and your partner in a time of need.