One of the most immediate financial changes after marriage is how you interact with the IRS. Once you are married, you lose the ability to file as "Single" . You are now faced with a choice: Married Filing Jointly (MFJ) or Married Filing Separately (MFS). This decision can result in a "marriage bonus" (paying less tax than you did as singles) or a "marriage penalty" (paying more) . Understanding the mechanics of these statuses is essential for maximizing your household's take-home pay.

The Choice: Jointly vs. Separately

For the vast majority of couples, filing jointly is the most tax-efficient path. When you file jointly, you combine your incomes, deductions, and credits onto a single return .

Why Filing Jointly Usually Wins

Higher Standard Deduction: For 2024, the standard deduction for a married couple filing jointly is $29,200—exactly double the single deduction .
Better Tax Brackets: The income thresholds for joint filers are generally wider, which can prevent a high-earning spouse's income from being taxed at a higher rate if the other spouse earns significantly less .
Eligibility for Credits: Many valuable tax breaks, such as the Child and Dependent Care Credit and education credits (like the American Opportunity Tax Credit), are often unavailable or severely limited for those who file separately .

When Filing Separately Makes Sense

While rare, there are specific scenarios where filing separately is the smarter move:

Student Loans: If you are on an income-driven repayment plan, filing separately may keep your individual monthly payments lower because they will be based only on your income, not the combined household income .
Medical Expenses: If one spouse has very high out-of-pocket medical costs, it may be easier to hit the 7.5% of Adjusted Gross Income (AGI) threshold required for a deduction if you only use that spouse's lower individual income .
Legal/Liability Concerns: If you are in the process of separating or do not trust your spouse's financial reporting, filing separately protects you from being held "jointly and severally liable" for any errors or fraud on their return .

The Marriage Bonus and Penalty

The "marriage bonus" typically occurs when one spouse earns significantly more than the other. By filing jointly, the higher earner's income is "pulled down" into the lower tax brackets of the lower-earning spouse . Conversely, a "marriage penalty" can occur when two high-earners with similar incomes are pushed into a higher tax bracket when their incomes are combined .

Scenario	Potential Outcome	Why?
One High Earner, One Low Earner	Marriage Bonus	High income is shielded by the lower earner's unused lower brackets .
Two Equal High Earners	Marriage Penalty	Combined income may cross into a higher marginal tax rate .
Two Low/Moderate Earners	Neutral/Bonus	Standard deduction and credits usually provide a net benefit .

Gift Splitting: Moving Wealth as a Team

Marriage also changes how you can give money away. The IRS limits how much you can give to an individual each year without reporting it (the annual gift exclusion). For 2024, this is $18,000 per person . However, married couples can use Gift Splitting.

The Power of Two

If you want to give a large gift (e.g., to a child for a house down payment), you and your spouse can "split" the gift. This allows you to give up to $36,000 to a single recipient tax-free by combining your individual exemptions .

Requirement: Both spouses must consent to the split on a federal gift tax return (Form 709) .
Community Property States: In states like Arizona or California, gifts made from "community property" (assets earned during the marriage) are often automatically considered split .

The Administrative Checklist: Name and Address

Before you file your first "Married" return, you must handle two critical administrative tasks:

The Social Security Administration (SSA): If you changed your name, you must notify the SSA immediately. If the name on your tax return doesn't match the name on file with the SSA, the IRS may reject your return or delay your refund .
IRS Form 8822: If you moved into a new home together, file this form to ensure the IRS has your correct address for any refunds or correspondence .

Frequently Asked Questions: Taxes and Marriage

Q: Can we still file as "Single" if we got married on December 31st?
A: No. Your marital status on December 31st determines your status for the entire year in the eyes of the IRS .

Q: What is "Joint and Several Liability"?
A: It means the IRS can hold both spouses responsible for the entire tax bill, interest, and penalties, even if only one spouse earned the income or made the error .

Q: Do we have to file jointly to get the $500,000 capital gains exclusion on our home?
A: Yes. Married couples can exclude up to $500,000 of profit from the sale of their primary residence, whereas singles are limited to $250,000 .

Q: How do we adjust our paychecks for our new status?
A: You should both submit a new Form W-4 to your employers. Use the IRS Tax Withholding Estimator to ensure you aren't under-withholding, which could lead to a surprise bill in April .