Where on my tax return can I find my modified adjusted gross income?

The MAGI is not on your tax return or in Turbo Tax.   There are many different MAGI.  What do you need it for?  

For this information, you will have to pay for TurboTax to see the worksheets that go with your tax return. However, suppose you want to calculate your MAGI for your purposes, for instance, to see how much of your Social Security Income is taxable, or to see the maximum contribution to your retirement account. In that case, you can complete the 590 A 2024 form found on the IRS website, beginning on page 15, which provides  Worksheet 1-1, line 7, to figure your modified AGI for traditional IRA purposes. Worksheet 2-1, line 10, is for Modified Adjusted Gross Income for Roth IRA Purposes. I hope this helps and reduces the hostility for asking a very important question, because it is not the same as AGI.