Her energy adviser said she would work on a tax if Congress wanted it.
The R&D tax credit was expanded last year so that startups can benefit from it.
Reid said the GOP demanded "anti-environment" provisions added in exchange.
The changes come after its e-File PIN system proved vulnerable to hackers.
Trump has so far refused to release his tax returns.
Facebook and Apple received the largest benefits from the tax break.
"We must make supporting working families a precondition to our cooperation," Sherrod Brown said.
The Tax Foundation analyzed 86 commonly proposed tax changes.
The measures would exempt feminine hygiene products from sales taxes.
Scammers are demanding that victims pay a fake "federal student tax," the IRS said.
Likely GOP nominee Donald Trump has not yet released his returns.
The agency expects 150 million returns this season, with 100 million already filed.
Trump has proposed repealing the estate tax.
Rep. Jim Renacci's proposal would replace the corporate income tax with a consumption tax.
The plan would cost $191 billion after economic effects are considered, the Tax Foundation said.
The proposal calls for lowering rates and revamping the IRS.
The resolution says such a policy "would be detrimental to American families and businesses."
The new "Get Transcript" feature uses a multi-factor authentication process.
His campaign previously said a form showing he received the credit was a mistake.
"As small businesses goes, so goes the American economy," Rep. Randy Hultgren said.
Hillary Clinton has made more than 30 years of her returns public.
National Taxpayer Advocate Nina Olson called for IRS outreach to participants in the space.
Republicans have leveled a string of complaints against the agency.
Amid mounting pressure for Donald Trump to release his tax returns, Rubio has made some of his tax...