Got a 4883c letter from IRS to confirm my identity before they can process return? If that's the case, why is TurboTax saying my return accepted? This seems wrong.

Accepting a tax return simply means the return was received by the IRS without any obvious errors that would have caused the IRS to reject the tax return.

After the IRS accepts a federal tax return TurboTax receives no further information from the IRS concerning the tax return.

Go to this IRS website for information on the 4883C letter - https://www.irs.gov/individuals/understanding-your-4883c-letter

"Accepted" does not mean the same as "approved"  -- when you e-filed you got an email telling your that your return was accepted.

https://ttlc.intuit.com/questions/2840013-does-accepted-mean-my-refund-is-approved