Darnestown shares zip codes with both Germantown (20874) and Gaithersburg (20878).
The combined state/county transfer tax is 1.5% and is typically split between the buyer and seller.
There is also a recording tax of .69% up to $500,000, then 1% of the portion over $500,000.
A credit of 1/4% is given on the transfer tax for first time MD homebuyers. Also, a $345 credit on the recording tax if the property is your principal residence.