Why Is My Tax Refund So Small This Year? 9 Common Reasons

A smaller refund usually isn't an IRS mistake. The federal tax system is mostly mechanical: if your tax bill went up, your withholding went down, or a credit you used to claim went away, your refund shrinks by exactly that amount. Here are the nine reasons that explain the vast majority of 'why is my refund so small?' questions — in rough order of how often they apply.

1. You got a raise

A raise pushes some of your income into a higher bracket. If your W-4 wasn't updated, your withholding scaled with your gross pay but not with the new marginal rate on the upper slice. A $10,000 raise that crosses you from the 22% bracket into the 24% bracket can shrink your refund by $200 or more even though more total was withheld.

2. A child aged out of the Child Tax Credit

The CTC is $2,000 per qualifying child under 17. The year your kid turns 17, you lose the credit (they may still qualify for the $500 Credit for Other Dependents, but that's $1,500 less per child). For a family with two teenagers, two CTC drops in two years is a $3,000 refund hit.

3. You picked up a side hustle that didn't withhold

1099 income, gig work, freelance projects, and cash side jobs don't have automatic federal withholding. If you earned $8,000 on the side and put it in your bank account untouched, you owe roughly $1,000–$2,400 in federal tax on it (15.3% self-employment tax plus your marginal income tax rate). That tax has to come from somewhere — and it comes out of your refund.

4. You stopped contributing to a 401(k) or HSA

Pre-tax contributions lower your taxable income. If you reduced your 401(k) contribution from $10,000 to $0 to fund a house down payment, you added roughly $2,200 to your federal tax bill at a 22% marginal rate. Same logic for HSA contributions, traditional IRA contributions, and pre-tax health insurance premiums.

5. The EITC phased out

The Earned Income Tax Credit phases out as your income rises. A married couple with two kids hits the EITC ceiling around $62,500 of earned income for 2025. Crossing that line means the credit drops to zero, which can shrink a refund by $4,000–$6,000 even though you earned 'only' a few thousand more.

6. You sold investments at a gain

Capital gains from selling stocks, crypto, or real estate aren't automatically withheld. A $20,000 long-term capital gain adds about $3,000 to your federal tax bill at the 15% rate — and unless you made an estimated payment in the quarter you sold, that tax comes from your refund.

7. You got married

Two earners with similar incomes can experience the 'marriage penalty' — combined income pushes into a higher bracket faster than if you each filed single. The brackets for MFJ aren't exactly 2x the single brackets at higher incomes. If both spouses earn $90,000, MFJ pushes some income into 24% that would have stayed in 22% if you were single.

8. You withdrew from a retirement account early

A 401(k) or traditional IRA withdrawal before age 59½ is taxed as ordinary income plus a 10% early withdrawal penalty (with some exceptions). A $15,000 early withdrawal adds $3,300+ to your tax bill at the 22% bracket — most of which the withdrawal didn't withhold for.

9. Withholding tables changed

When Congress passes mid-year tax changes or the IRS updates withholding tables (as it did in 2018 after TCJA), employers start withholding slightly less per paycheck. That means more take-home pay — but a smaller refund in the spring. If your W-4 hasn't been touched since 2017, this alone could explain a $500–$1,000 drop.

What to do

Run your full year through the Tax Refund Optimizer with your latest pay stub. If the projected refund is smaller than you'd like and you don't owe, you can either increase per-paycheck withholding via a fresh W-4 or accept the smaller refund as more take-home pay. If you actually owe, increase withholding now — there are still pay periods left in the year to catch up and avoid an underpayment penalty.