[Holland Hacker]

Here is a blurb from Marylands webite for estianted taxes on gambling winnings:

Gambling Winnings
If you receive winnings from Maryland lottery games, racetrack betting or gambling, you must pay income tax on the prize money. This would apply if you were either a resident of Maryland or a nonresident.

If your winnings total more than $5,000, Maryland income taxes will automatically be withheld from your newfound income.

If your prize money totals between $500 and $5,000, you must file Maryland Form 502D and pay the tax on that income within 60 days from the time you receive the prize money.

You should calculate the amount of tax due following the instructions included with Form 502D. You can claim a credit for taxes paid with Form 502D when you file your annual income tax return.

If you win less than $500, you don't have to file Form 502D, but you still must report the winnings and pay tax on it when you file your annual state income tax return.

If you fail to pay the required estimated taxes due or report income, you could be subject to penalty and interest charges.

It appears as though you are correct that you owe the underpayment penalty. I did not see the typical safe harbor provisions based on prior years that most other states have in Maryland, and I thought I had it rough in Nj wih taxes.