IRS extended filing and payment deadline for California. Does TurboTax automatically calculate the correct underpayment penalty, late filing and payment penalty?

No. TurboTax only calculates interest and penalty up to April 18. The IRS says it will automatically waive late filing and late penalties for California taxpayers impacted by severe winter storms, flooding, landslides, and mudslides beginning March 9, 2023.

If an affected taxpayer receives a late filing or late payment penalty notice from the IRS that has an original or extended filing, payment or deposit due date that falls within the postponement period, the taxpayer should call the telephone number on the notice to have the IRS abate the penalty.

 

The IRS automatically identifies taxpayers located in the covered disaster area and applies filing and payment relief. But affected taxpayers who reside or have a business located outside the covered disaster area should call the IRS disaster hotline at 866-562-5227 to request this tax relief.

See IRS provides tax relief for victims of severe winter storms, flooding, landslides and mudslides in California.