If one received payment for difficulty of care, claimed it as income, paid taxes and wanted to submit a correction to IRS, how would one go about it?

I am a parent with an adult son with a severe disability. He is on the Medicaid Home and Community Base Program. Notice 2014-7 was issued on 1/21/2014 stating "difficulty of care" payments are excluded under Section 131 of Title 26 of the IRS Code. Please confirm the reason the Notice 2014-7 was issued was - because state DHHS agencies were withholding taxes and sending W2's or sending 1099's to parents or caregivers supporting individuals under "difficulty of care". When under Title 26 Section 131 it clearly states the exclusion and inclusions of when someone has to claim the income they received to the IRS. If not, please advise why Notice 2014-7 was issued? Please confirm in Notice 2014-7 it states "period of limitation on claims for a credit or refund under Section 6511 has not expired" - suggest that an individual who received payment for "difficulty of care" and claimed it as income and paid taxes could submit to the IRS a correction of earned income for previous taxable years (2012 and 2013) if not expired? Is this correct? Your responses would be greatly appreciated!