IRonMaN - in Maryland if you have a pass-through business tax credit you must "by law" e-file the tax return.  The line (current year line 25) is not supported by ProSeries.  It has never been supported by ProSeries.  You have not been allowed to mail in these returns.  I've had multiple clients take their tax returns down to the Governor's office or the Comptroller's office and hand in their tax forms **bleep**ing about this.  Finally, MD issued a waiver form (500CRW) in case your software does not support this line.  All it is is a pass-thru number in which you would pdf attach the business credit form.  You cannot override, or anything.  I've sent in requests for this for 6 six years.