Your paycheck was consistent for months — then suddenly this week it's hundreds of dollars smaller. What changed? Paychecks rarely drop without a reason. Here are the 8 most common causes and how to investigate.
8 Reasons Your Paycheck Went Down
1. You worked fewer hours
If you're hourly or your salary is tied to hours worked, taking PTO, sick leave, or unpaid time off will reduce your gross pay for that period.
- Check: Compare "Hours Worked" or "Regular Hours" on this pay stub vs. the previous one.
- PTO vs. unpaid: Paid time off shouldn't reduce your check (unless you're out of PTO balance). Unpaid leave will.
2. No overtime or bonus this period
If you regularly work overtime or receive recurring bonuses/commissions, a period without them will look like a pay cut.
- Check: Look for "Overtime," "Bonus," "Commission," or "Shift Differential" lines that were on your last stub but not this one.
3. Benefit deductions increased
Health insurance premiums, 401(k) contributions, HSA, FSA, or other pre-tax deductions may have increased — either because of open enrollment, a plan change, or an automatic percentage adjustment.
- Check: Compare "Pre-Tax Deductions" section line by line. Did health insurance, dental, 401(k), or HSA go up?
- Why it happens: Annual rate adjustments, switching to family coverage, or increasing your 401(k) percentage.
4. Your W-4 changed
If you or your employer updated your W-4, federal withholding can jump significantly. This often happens after a life event (marriage, divorce, new dependent) or if HR corrected an error.
- Check: Compare "Federal Tax" or "FIT" line on this stub vs. last period.
- What to do: If you didn't intend to change your W-4, ask HR if it was updated and why.
5. New garnishment or court order
Child support, student loan garnishment, tax levy, or creditor garnishment will appear as a new deduction, often without warning if the order was just processed.
- Check: Look for "Garnishment," "Levy," "Child Support," or "Court Order" in post-tax deductions.
- What to do: Contact HR and the issuing agency to confirm the amount and duration.
6. Loan or advance repayment
If you took a payroll advance, 401(k) loan, or company equipment loan, repayment may have started automatically this period.
- Check: Look for "Loan Repay," "Advance," or "Equipment" deductions.
- What to do: Verify the repayment schedule with HR or payroll.
7. Tax threshold crossed (Social Security cap)
If your year-to-date earnings crossed the Social Security wage base ($176,100 in 2025), Social Security tax (6.2%) stops — but Medicare (1.45%) continues. This makes your paycheck larger, not smaller, so it's not the culprit here. But if you're near the cap, ask HR.
8. Payroll error
Sometimes it's just a mistake — wrong hours entered, duplicate deduction, or system glitch.
- Check: Compare this pay stub to the previous 2-3 stubs line by line.
- What to do: If the numbers don't make sense, email payroll immediately with your pay stub attached and ask for a breakdown.
How to Investigate: Step-by-Step
- Pull up your last 2-3 pay stubs for comparison.
- Check gross pay first: Is it lower? If yes, you worked fewer hours or lost overtime/bonus. If gross is the same but net is lower, it's deductions or taxes.
- Compare federal tax withholding: Did it jump? Your W-4 may have changed.
- Compare pre-tax deductions: Health, 401(k), HSA, FSA — did any increase?
- Look for new post-tax deductions: Garnishment, loan repayment, union dues, etc.
- Check hours worked: Did you take unpaid leave or miss days?
- Look for missing bonuses/OT: Was there a one-time payment last period that's gone this period?
Once you've identified what changed, decide if it's correct (e.g., you did increase your 401(k)) or an error (e.g., wrong withholding). If it's an error, contact HR or payroll immediately with your pay stubs for proof.
When to Contact HR or Payroll
Reach out if:
- Your gross pay is wrong (doesn't match hours worked or salary).
- Federal or state withholding jumped without you changing your W-4.
- A new deduction appeared that you didn't authorize.
- Benefit deductions don't match what you elected during open enrollment.
- The math simply doesn't add up and you can't find the reason on your pay stub.
Provide your pay stubs from this period and the previous 2-3 periods so HR can compare and spot the discrepancy quickly.