Why don’t i qualify for the stimulus check ?

[DMarkM1]

At this point any missed stimulus payments have to be claimed on your 2020 tax return in the form of a Recovery Rebate Credit. Your eligibility is based on the information in your 2020 tax return only. Generally, the qualifications are:

• Be a US citizen
• Have a valid Social Security Number
• Have income under $75,000
• Not be claimed as a dependent on someone's 2020 tax return

If you have received any stimulus payments in rounds one and/or two, your Recovery Rebate Credit will be reduced by those amounts.

To recap the stimulus amounts are:  

Round one:  $1200 (2400 if filed jointly) plus $500 for each qualifying dependent child age 16 or under

Round two:  $600 (1200 if filed jointly) plus $600 for each qualifying dependent child age 16 or under.

Here is a link with more information on the Recovery Rebate Credit.

[Hal_Al]

The requirement is not just whether you are actually claimed as a dependent, it's whether you qualify to be claimed as a dependent.