Hatch: HHS blew through its own PPACA deadline

But the PPACA penalty on individual taxpayers who fail to have "minimum essential coverage" (MEC) did start to take effect in 2014. Many employers wanted to get the employer APTC notices so they could help employees resolve any APTC-related tax problems, Hatch writes in the letter to Burwell.

Hatch is asking to give him more details about how HHS will comply with the employer APTC notice requirement, and whether it will consider offering a tax penalty grace period for employees if an exchange calculates APTC amounts incorrectly because of a failure to check with employers to verify the employees' descriptions of their benefits.

"If HHS is holding the notices and mailing them in batches after open enrollment, taxpayers may owe penalties for the months HHS failed to notify them of HHS' mistake," Hatch writes. "How will you help these taxpayers? How will HHS identify employers for whom they do not have a full address?"

Hatch also asked HHS how it will ensure that APTC applicants are reporting their employers' employer identification numbers correctly.

See also: Lockton: IRS survey may hint at PPACA employer reporting delay