WASHINGTON – The Internal Revenue Service reinstated the tax-exempt status of the Zionist Organization of America in a decision announced May 15. A year ago the IRS rescinded the tax-exempt status because ZOA had not filed a tax return for three consecutive years.“The work of the ZOA has never been altered or diminished one iota during this period,” ZOA President Morton Klein said in a statement Monday.Klein told JTA last year that the failures to file were due to confusion over the status of a school in Israel run under ZOA auspices, and because of erroneous advice from a tax accountant.Donations to ZOA have remained deductible in the meantime, as they were directed through a third party donor advised fund.In the same announcement, ZOA said its annual dinner, to be held in November, will honor casino magnate and philanthropist Sheldon Adelson.