Social security lump sum earlier year tax return amendment

I received social security benefits this year that were back benefits for prior years. Do I amend my returns for those prior years? Are the back benefits paid in this year for past years taxable this year?

You can't amend returns for prior years to reflect social security benefits received in a single lump-sum in the current year. You must include the taxable part of a lump-sum payment of benefits received in the current year (reported to you on Form SSA-1099, Social Security Benefit Statement) in your current year's income, even if the payment includes benefits for an earlier year.

However, there are two ways to determine the amount of income to include:

You can select the lump-sum election method if it lowers the taxable portion of your benefits: