I amended my 2019 tax return to change my dependency status because I didn't qualify for the stimulus check. Will I now be able to receive a stimulus check?

[Stinkerbellkity]

Yes, but you likely will receive it in 2021 when you do your 2020 tax return.  Amended returns have to be filed by mail and the .  IRS right now is not processing mailed returns. In a normal year, it can take the IRS up to 16 weeks to process an amended return, this year it will likely take much longer, even until after stimulus checks are being issued.  You can. however, take one next year when you file.

[DawnC]

Stimulus payments will be based on information from your most recent tax filings, either 2019, or 2018 if you haven't filed this season yet. But, the amount paid to you now will be reconciled on next year’s tax return based on your current 2020 situation.

The amendment will not get the the advance payment any sooner.  Amendments are not being processed right now and it will be months before yours is processed.  If you are not a dependent on someone's 2020 tax return, you can file a 2020 tax return and claim the credit is you do not get the advance later this year.