If you have met the SPT Substantial Presence Test, you may file as a resident in 2020. Your residency termination date is generally December 31 of the year you leave which is 2020.
In your situation, if you have stayed on H-1B visa and met SPT before March 2020, you are not a dual status. It is not an option. You have to file as a US resident with a Form 1040. To read IRS link, click here: Last year residency
If you are filing a resident, you are filing for the full year jointly with your spouse and qualify for the Child related credits if you meet the all the requirements.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
