Q: I am helping with my sister’s income taxes. On her 1099-R, Box 2A, the taxable amount is unknown. I don’t know how to report whether her survival annuity is taxable or nontaxable. A: While most of her annuity will be taxable, a portion will not. To find out how much of it will be tax-free, download a copy of IRS Publication 721, Tax Guide to U.S. Civil Service Retirement Benefits.