<prompt> Human: This will be the first year filing as married for me and my wife. Last year, I made 108k and owed 500 or so. She earned 55k and owed 100. She left her withholdings as single2 I just had her change it to single0. I changed mine mid year to married0. This year, on our combined income of 166k, before deductions and such, we owe 4500!!! Our individual incomes didnt rise significantly, why did our federal tax owed? Seems like we are financially penalized for being married, even though we dont earn more.What is the proper W4 combination we should use? I think dropping hers to single0 will even our her liability, bu I apparently need to withhold an extra amount? Best as I can figure, another 100 or so.Does this sound reasonable?  <response>: Seems like we are financially penalized for being married, even though we dont earn more.You could be hitting the true marriage penalty i.e. where your MFJMFS liability is greater than what it would be if you were unmarried filing single or singleHOH, but I think its much more likely to be nearly entirely a withholding issue. The withholding tables are built around one earner with only one simultaneous job. Adding a second well-paying job will break that assumption hard, and put you into situations like yours.Edit: If you are hitting it, youll be happy to know that youre less likely to this year. The MFJ brackets were changed to eliminate the bracket-caused marriage penalty, though Im not sure you have a high enough joint income to be hitting that though. I changed mine mid year to married0Married0 would almost certainly be underwithholding dramatically for the reasons mentioned above. The 0 instead of 4 or whatever would mitigate the hit, but wouldnt be enough to eliminate it. What is the proper W4 combination we should use?Use the two-earnersmultiple-jobs worksheet on the back of the W4, or, once its back online in a month or so, the withholding calculator linked by automod. There are also non-IRS calculators you can find, that may or may not have been updated for the new tax law. 