Democratic nominee Edward Markey's campaign pounced on the report, charging Gomez of engaging in a tax "scam" and calling for him to release his tax returns for 2005, to see how much the deduction saved Gomez.
But Gomez declined to comment on the tax deduction, and when asked, declared that he hadn't broken any rules.
"I've been inside the rules for everything I've done my whole life," he told local news station WHDH.
The Internal Revenue Service named similar deductions to its list of "Dirty Dozen" tax scams in 2005, classifying it as one way to "use ... tax-exempt organizations to improperly shield income or assets from taxation."
When addressed with the classification of the deduction as a "scam" by the IRS, Gomez declined to comment.
Later, in response, his campaign charged that Markey supported the tax breaks Gomez used with a vote in Congress.
But the Democratic Senatorial Campaign Committee is working to make the deduction a problem for Gomez, and, in a release the committee will issue later today shared with The Hill, is asking the following questions of the Republican:
• What was your tax rate the year you took advantage of this scam?
• How did you hear about this tax break?
• Who put you in touch with National Architectural Trust?
• Did you know that Congress and the IRS had already labeled this one of the worst tax scams in the entire country?
• Do you believe Congress should make this tax scam illegal?
“Gabe Gomez needs to be forthright and answer these simple questions,” said Justin Barasky, DSCC spokesman. “Just like Mitt Romney, Gomez is taking advantage of obscure tax tricks and refusing to provide the public with any answers.”
The issue could complicate Gomez's pursuit of Secretary of State John Kerry's (D) seat, as Democrats look to make it a central focus of their attacks on the candidate.
Tax deductions used by Romney to reduce his overall tax burden were used to his detriment by Democrats during the 2012 elections, and Democrats look to be initiating a similar line of attack against Gomez, to paint him as a wealthy Republican out of touch with average Massachusetts voters.
Indeed, Sen. Elizabeth Warren (D) won election to the Senate largely on a populist pitch that resonated with voters in 2012. And Gomez has tried to frame himself as "new kind of Republican" up against an out-of-touch creature of Washington in Markey.
An affiliation with Romney could further complicate Gomez's bid, as President Obama is popular in the state, having won with more than 60 percent support in 2012. Democrats hope to tie the national Republican brand around Gomez's neck — and identifying him as another Romney-esque businessman is one clear way to do so.
Republicans have hit back at Markey, with Massachusetts Republican Party Chairwoman Kirsten Hughes accusing him of "another attack and distract ploy" and noting that Markey went negative first in the race — an indication, Republicans say, that the front-runner is nervous.
Republicans have called for Markey to release his own tax returns. And they've noted that he voted to preserve the very program that provided Gomez with the deduction.
National Republican Senatorial Committee communications director Brad Dayspring highlighted Markey's long tenure in Congress in a statement that accused the congressman of "complicating the tax code."
"Ed Markey has been in Washington for nearly forty years, complicating the tax code to the point where it's a nightmare for hard working people in the real world. Despite making taxpayers' lives hell for over four decades, Markey is so arrogant that he refuses to release any of his own tax returns for the thirty-six years that taxpayers have paid his salary and for his home in Maryland," he said.
"Ed Markey is a career politician who was embroiled in a check bouncing scandal and has repeatedly given himself pay raises with tax payer dollars. Until Markey releases his own tax returns, he should be quiet and focus on creating opportunity, investment and jobs — reforming the tax code that he helped screw up is a good place to start," he added.
—This post was updated at 9:53 a.m. to reflect comment from the NRSC and the Massachusetts Republican Party.