He also pleaded guilty to one count of obstructing and impeding the due administration of the internal revenue laws. The Justice Department said the phony deductions cost the government more than $1.5 million.

Doonan, who had been preparing federal tax returns since 2009, prepared and filed more than 3,000 federal tax returns annually. He was accused of regularly filing false and fraudulent ones.

Among his techniques were adding false medical and dental expenses, state and local taxes, home mortgage interest, gifts to charity, job expenses and certain miscellaneous deductions. He also filed Schedule Cs for a variety of bogus consulting businesses for clients that did not own and operate or occur business losses.

Sentencing is scheduled for February 10. Doonan faces a maximum of three years in prison for the aiding and assisting in the preparation of a false return count and three years in prison on the obstruction of the internal revenue laws count, along with supervised release and monetary penalties.