How Getting Married Changes Your Tax Brackets

When you're new to filing taxes, the very first question you have to answer is "What is your filing status?"

This single choice—Single, Married Filing Jointly, or something else—is one of the most important decisions you'll make all year. It's not just a label for the IRS; it's the master key that determines which set of rules applies to you.

It changes the size of your tax brackets, the amount of your standard deduction, and your eligibility for certain tax credits.

In our last article, we explained how federal tax brackets work like a series of "buckets." Now, we'll explore how getting married or filing as a single person changes the size of those buckets.

This leads to two famous (and often misunderstood) financial outcomes: the "Marriage Bonus" and the "Marriage Penalty."

A Quick Refresher on "Tax Buckets"

Before we compare, let's re-establish the core concept. The U.S. has a progressive tax system.

This does not mean you pay one single rate on all your income. It means you pay different rates on different portions of your income. Your income fills a 10% "bucket" first, then spills over to fill a 12% "bucket," then a 22% "bucket," and so on.

Your "filing status" is what determines the size of each of your buckets.

There are five statuses, but the main ones we'll compare are:

1. Single: For unmarried individuals.
2. Married Filing Jointly (MFJ): For legally married couples who want to combine their incomes and file one, single return.

The Two Main Lifestyles (Single vs. MFJ)

Let's look at the 2025 federal tax brackets for the two most common statuses. Notice how the income levels are different for every single bracket.

What Do You Notice?

At first glance, you might see that the "Married Filing Jointly" (MFJ) brackets are... exactly double the "Single" brackets.

• 10% Bucket (Single): $11,600.
• 10% Bucket (MFJ): $23,200. (Exactly 2 x $11,600)
• 12% Bucket (Single): Ends at $47,150.
• 12% Bucket (MFJ): Ends at $94,300. (Exactly 2 x $47,150)

This is a (relatively) new change. The 2017 Tax Cuts and Jobs Act (TCJA) fixed what used to be a major "Marriage Penalty" for most Americans by making these brackets a simple double.

So, if you are a married couple where each person earns $50,000 (for $100,000 total), your tax bill will be exactly the same as two single people each earning $50,000. For most people, marriage is now "tax neutral."

But this simple doubling does not apply to everyone. This is where the "Bonus" and "Penalty" come in.

The "Marriage Bonus" (When One Spouse Earns More)

The "Marriage Bonus" is a very real tax break that typically occurs when one spouse earns significantly more money than the other.

Let's look at an example.

The Couple:

• Spouse A: Has an income of $120,000.
• Spouse B: Has an income of $0 (a stay-at-home parent, for example).
• Total Household Income: $120,000

Calculation 1: Taxed as a "Single" Filer

If Spouse A were not married, their $120,000 income would be taxed as a Single filer:

• 10% Bucket: $1,160
• 12% Bucket: $4,266
• 22% Bucket: $11,745
• 24% Bucket: $4,674 (on the income from $100,526 to $120,000)
• Total Federal Tax as "Single": $21,845

Calculation 2: Taxed as "Married Filing Jointly"

Now, they file together (MFJ) with the same $120,000 household income:

• 10% Bucket: $2,320 (on the first $23,200)
• 12% Bucket: $8,532 (on the income from $23,201 to $94,300)
• 22% Bucket: $5,654 (on the income from $94,301 to $120,000)
• 24% Bucket: $0
• Total Federal Tax as "Married": $16,506

The Result: A "Marriage Bonus" of $5,339

By getting married, this household saves $5,339 in federal taxes.

Why? Because Spouse A (the high earner) gets to "use" all of Spouse B's (the $0 earner) empty tax buckets. Instead of their income being taxed at 24%, the marriage "pulls" a huge portion of that income back down into the much lower 10% and 12% MFJ buckets.

The U.S. tax system is designed to benefit households with a single, primary earner.

The "Marriage Penalty" (Where It Still Exists)

The "Marriage Penalty" is a situation where a married couple pays more in tax by filing jointly than they would if they had just stayed single.

As we saw, the tax brackets are mostly fixed, so this is rare. Today, the Marriage Penalty primarily hits two groups:

1. Very High Earners

Look at the tax bracket table again. The "doubling" works perfectly... until you get to the 37% bracket.

• 37% Bracket (Single): Starts at $609,351
• 37% Bracket (MFJ): Starts at $731,201

If you are two high-earning doctors, and you each make $500,000 (for a $1 million household income), you have a penalty.

• As Singles: Neither of you would hit the 37% bracket.
• As Married: Your combined $1M income is way over the $731,201 threshold, and a large chunk of your income is now taxed at the highest 37% rate.

2. The "Deduction Cap" Penalty (This is the common one)

The more common penalty isn't in the brackets at all—it's in the deductions.

The most famous example is the SALT Deduction ("State and Local Tax").

• The IRS lets you deduct the money you paid in state/local taxes from your federal income.
• A Single filer can deduct up to $10,000.
• A Married Filing Jointly couple can also only deduct $10,000.

This is a huge penalty. If two single people (a boyfriend and girlfriend) live together, they can each deduct $10,000, for a total of $20,000. The moment they get married, their combined deduction is sliced in half to $10,000.

This same logic applies to other phase-outs, like the Earned Income Tax Credit (EITC) for low-income earners, where combining two small incomes can make the couple ineligible.

What About the Other Statuses?

There are two other important statuses that serve specific needs.

• Married Filing Separately (MFS):This is almost always the worst option. The tax brackets are exactly half of the MFJ brackets, but you are instantly disqualified from a huge number of popular tax credits (like student loan interest deductions and the EITC).
  • Why does it exist? It's for rare, specific legal situations. The most common is a couple in the middle of a messy divorce, or when one spouse wants to protect themselves from the other's (potentially fraudulent) tax return.
• Head of Household (HoH):This is a special, better status for single people with dependents.
  • Who is it for? An unmarried person who is paying for more than 50% of the home for a qualifying dependent (like a child or an elderly parent).
  • What's the benefit? The "buckets" are larger than for a Single filer. For example, the 12% bucket for a Single filer stops at $47,150, but for a Head of Household, it goes all the way to $63,000. It's a significant tax break designed to help single parents.

Final Verdict: What Does This Mean for You?

You don't get to "choose" your status based on what's best. Your status is determined by your life:

• If you are unmarried on December 31st, you are Single (or HoH).
• If you are married on December 31st, your only real choice is MFJ or MFS.

For 99% of married couples, Married Filing Jointly (MFJ) is the best choice.

The system is no longer "penalizing" most couples. It is designed to give the biggest benefit to couples with a single, high earner, but it doesn't punish couples who both work—at least, not until you get into the messy details of deduction caps like the SALT limit.