For the third year in a row, retirement plan contribution limits tied to cost of living adjustment (COLA) figures remain unchanged, the IRS has announced.  This means the maximum employee deferral contribution limit for 401(k) and 403(b) plans stays at $16,500 for 2011, with “catch-up” contributions for employees over age 50 remaining at $5,500.  Other figures, including the annual additions limitations, compensation limits for purposes of determining highly compensated or key employee status, and the social security wage base also remain unchanged.