Up to tax year 2017, form 1040 had line 37 for Adjusted Gross Income (AGI). On your 2018 form 1040, Adjusted Gross Income (AGI) is on line 7.
How about tax year 2019, What lines do you add to get MAGI
It isn't a matter of adding lines.
"To calculate your modified adjusted gross income, take your AGI and add back certain deductions. Many of these deductions are rare, so it's possible your AGI and MAGI can be identical. According to the IRS, your MAGI is your AGI with the addition of the following deductions, if applicable:
Student loan interest
One-half of self-employment tax
Qualified tuition expenses
Tuition and fees deduction
Passive loss or passive income
IRA contributions
Taxable social security payments
The exclusion for income from U.S. savings bonds
Foreign earned income exclusion
Foreign housing exclusion or deduction
The exclusion under 137 for adoption expenses
Rental losses
Any overall loss from a publicly traded partnership"