tldr: The deadline to submit 1st and 2nd quarter quarterly estimated tax payments in 2022 was extended to July 15th 2022, but the Maryland Comptroller's office is seemingly unaware of this and is charging interest to anyone who submitted these estimated taxes after their original due dates of April 15th and June 15th.

I paid quarterly estimated Maryland state taxes in 2022, and filed my return last week. I just received my Maryland tax refund, and noted that it was about $50 lower than it should have been. So I called the Comptroller to find out why, and was told it was an interest charge for a late payment of my 1st quarter estimated taxes. I checked the date that I paid, and it was on May 27th, 2022. This was not late, because the Comptroller extended the deadline for 1st and 2nd quarterly estimated taxes to July 15th, 2022.

Somehow, the Comptroller's office was not aware of this, and is seemingly charging interest to anyone who submitted their quarterly estimated taxes after the original deadlines of April 15th and June 15th. If that could be you, I would encourage you to call Taxpayer Services to enquire about this (Numbers below), as I highly doubt they will fix this automatically now that they are aware of the problem. The person I spoke with on the phone was very nice and helpful, but she had no idea about this change in law that took place last year.

Maryland taxpayer services: 410-260-7980 from Central Maryland or at 1-800-MD TAXES from elsewhere