Where can I find Line 9 on Mn tax form?

To qualify for this nonrefundable credit, all of these must be true:

• You are married and filing a joint return
• You and your spouse have taxable earned income, taxable pensions, or taxable Social Security income
• Your joint taxable income is at least $47,000
• The income of the lesser-earning spouse is at least $30,000

Nonrefundable tax credits can reduce the amount of tax you owe, but they do not increase your tax refund or create a tax refund when you wouldn’t have already had one.

To check if you qualified for the credit check  Schedule M1MA, Marriage Credit line 21 

The total of all nonrefundable credits from Schedule M1C goes on line 16 of Form M1

If using TurboTax online check,  How do I preview my TurboTax Online return before filing?

MN Marriage Credit