Marriage has a lasting effect on your finances, for better or for worse. Most people are prepared to pay daily expenses and plan for a future together. But few give much thought to how their marriage affects their Social Security benefits.

There are three important changes that take place within the first year of getting married. We'll cover each of them in detail below so you know what to expect.

Smiling couple posing for wedding photos.

Image source: Getty Images.

1. You become eligible for a spousal benefit on your new spouse's work record

You probably know that marriage makes you eligible for a spousal benefit on your new partner's work record, assuming your partner has worked long enough to earn a Social Security retirement benefit. But many believe they become eligible for a spousal benefit as soon as they get married. That's not always true, though.

Typically, you must be married to your partner for at least one year before you become eligible for spousal benefits on their work record. However, there are a few exceptions. If you're the parent of your spouse's child, the one-year rule doesn't apply. It also doesn't apply to those who were entitled to Social Security benefits in the month before the month they got married.

This doesn't matter much to young couples who aren't even old enough to claim Social Security, but it's something to bear in mind if you're nearing retirement age when you marry. You may have to wait slightly longer than you planned to claim your spousal benefit if your marriage hasn't hit the one-year mark yet. However, even if you can't yet claim a spousal benefit, you can still claim a retirement benefit of your own beginning as soon as you turn 62.

2. You become ineligible for a spousal benefit on your ex-spouse's work record

It's possible to claim a spousal benefit on your ex's record if you were married for at least 10 years before splitting. However, that eligibility depends upon you staying single. If you choose to remarry, you will no longer be able to claim an ex-spousal benefit.

Again, this probably won't matter to you if you're not even eligible for Social Security yet. But if you were already receiving Social Security on your ex's work record, be prepared for the Social Security Administration to switch you over to your new partner's Social Security benefit, assuming they've signed up.

Ex-spousal benefits permit you to claim even if your ex hasn't applied yet as long as you've been divorced for at least two years. This isn't true for current spousal benefits. You cannot claim these until your spouse applies for their own retirement benefit. So if you were claiming ex-spousal benefits and then marry someone else who hasn't yet applied for Social Security, your checks may stop altogether unless you're eligible for a retirement benefit of your own.

3. You become eligible for a survivors benefit if your spouse passes away

Marriage also entitles you to a spousal benefit if your partner unexpectedly passes away, but as with spousal benefits, this eligibility doesn't kick in right away. Typically, you must be married for at least nine months before you become eligible for a survivors benefit on your partner's record. However, the Social Security Administration will waive this requirement if you meet one of the following criteria:

  • You're caring for the deceased worker's minor child.
  • You were eligible for Social Security benefits on a qualifying worker's record in the month before the month you married the deceased worker.
  • The deceased worker's death was accidental.
  • The deceased worker's death occurred in the line of duty while serving in the military.
  • You and the deceased worker had been previously married and that marriage lasted at least nine months.
  • The deceased worker was previously married to an institutionalized person and was unable to divorce them due to state law, but married you within 60 days of their institutionalized spouse's death.

If you qualify for spousal benefits and your spouse passes away, you can claim benefits as early as age 60 (50 if you're disabled) or at any age if caring for the deceased worker's minor child. Children could also be eligible for their own survivors benefit.

You probably don't have to worry too much about the finer points of Social Security benefits of spouses, but it's important to keep the basics in mind, especially if you plan to apply for Social Security soon. If you're not able to apply right away due to eligibility rules, you may have to find other ways to cover your expenses in the meantime.