<prompt> Human: Hi PF,I started a new job 2 months ago at a large tech company where Ill make between 130-150K excluding stock. My wife will start a new job as an OBGYN in September with a salary of 252,000.A co-worker of mine at my new job says she and her husband owed 40,000 despite marking 0 for everything and maxing out 401k. I am worried the same thing is going to happen to my wife and myself. We live in a state that has no state income taxes.Is the strategy here to pay quarterly taxes or ask to have additional money withheld from a paycheck?Why is our tax system so terrible that even after marking 0 people could still owe so much?  <response>: Use the W4 withholding calculator. You can request your employer to withhold an additional amount above whatever is calculated based on filing status and allowances. Some types of stock transactions are taxable events so that could add to your income for the year. 