A 401(k) plan generally allows most employees to contribute more to their retirement savings on a tax-deferred basis than an IRA.  Also, you cannot borrow from an IRA - a 401(k) plan can allow for participant loans.  In addition, no special tax treatment is allowed for a lump-sum distribution from an IRA, as can be the case with a distribution from a 401(k) plan.  Please refer to QPA's Comparison Chart for additional information.