My husband and I are not self employed, we each claim 0 deductions & have $200 each month applied toward our taxes. We have an underpayment penalty. Why?

When your incomes are combined, it can put you into a higher tax bracket than just one of your incomes alone.  So, say out of the $222,000 you earn $80,000, and your spouse earns $142,000.  The person with the income of $80,000 is in the 12% bracket when saying they are married on their W4.  In reality, when they combine their income with their spouses income they are actually in the 24% bracket.  So, all of your income is undertaxed by about 10%.  The other person making $142,000 is undertaxed on a portion of their income by about 2%.  This leaves both of you paying too little in taxes.

 For 2024, if you want to avoid having to owe at the end of the year again, it would be a good idea to complete a new W4 form for the one you make the most for or even for both of you.  You can choose to have an additional amount withheld from your wages as well.  There are a few ways to decide how much to have withheld.  In TurboTax, there is a W4 estimator, you can find this under Other Tax Situations>>Other Tax Forms>>Form W-4 and estimated Taxes. 

You can use the TurboTax W4 estimator outside of your tax return. 

You can also take the amount you owe extra this year and divide it by however many pay periods  you have and have that much extra withheld. Also, choosing the status on your W4 as married filing separately will increase the amount they withhold.   If either of you plan to get a raise, you would want to take that into consideration as well. 

You can also do a "dummy return" and see if you owe less when you file separately. Depending on your situation and any credits you are taking, this may or may not reduce your taxes due. 

Why do I Owe Taxes

Ways to Lower Your Tax Bill

Married Filing Jointly versus Married Filing Separately