"Because...growing income inequality has been so pronounced in the past year, what you can't do is pretend that only taxing millionaires is going to come anywhere close to fixing the problem," MacGuineas said on CBS News' "Face to Face."
President Obama is on the campaign trail this week, ahead of tax day, promoting the "Buffett Rule," named after Warren Buffett who advocates higher taxes for the wealthy. The proposed plan would impose a minimum tax rate on those earning more than a million dollars per year.
MacGuiness told host John Dickerson that raising taxes on the wealthy could have a negative impact on the economy as those who would be impacted make much of their money from dividends and capital gains.
"Having further taxes on the things that incentivize people to save and invest, [is] not necessarily good for the economy at a time when we're very focused on how do we grow the economy," she said. "It's going to have to be much more far-reaching than just looking at millionaires to fix this problem."
While Republicans and Democrats have been standing their ground, refusing to compromise, on tax policy, MacGuineas said there are ways to agree -- including getting rid of tax breaks for things like corporate jets.
"Big broad-based tax reform means that if you got rid of a lot of those tax breaks you could dramatically lower the rates, and still raise money to help close the deficit," she said.
During this election year, MacGuineas said be wary of election-year promises.
"Be careful of anything that sounds too good to be true. And unfortunately, what we're going to need are the things politicians don't love to talk about... And so if a politician is sort of peddling a budget that sounds great, filled with things you love and more tax cuts, those numbers aren't going to add up," MacGuineas said.
However, MacGuineas said the tax code can, and needs, to be fixed.
"The tax code is so bad there are a lot of ways to improve it," MacGuineas said.