After efile I noticed on my EIC box 4a & 4b we’re not marked for one of my dependents does this effect the refund amount and how do I fix this

Yes, that will affect your refund if you receive Earned Income Credit.  You can go back through the dependent screens in the My Info personal section of TurboTax.  Also, go back through the Earned Income interview in the Deductions and Credits section.  To count as a qualifying child for EIC, your child must have a valid Social Security number (not an ITIN).  She or he must also:

 

• Be your child (including legally adopted), stepchild, eligible foster child, sibling, half-sibling, step-sibling, or a descendant of any of them (for example, your grandchild or niece); and
• Be permanently and totally disabled or under the age of 19 as of December 31, 2019 (under 24 if a full-time student) and younger than you (or your spouse, if filing jointly); and
• Have lived with you (or your spouse, if filing jointly) for more than half the year in the United States (unless you were in the military); and
• Not file jointly with their spouse unless they weren't required to file but did so anyway to claim a tax refund.

Related Information:

• What are the qualifications for the Earned Income Credit (EIC or EITC)?

To visit the EIC section, search for EIC in TurboTax and select the link in your search results. However, don't do this until after you've entered all your income and personal information — otherwise you'll get an incorrect EIC calculation.