Social Security
Be sure to contact the Social Security Administration at least every three years. Those contributing to Social Security should check their contributions to insure they are correct. After 3 years the records go off-line and problems need to be researched manually which could take forever.
You can download form SSA-7004 Personal Earning and Benefit Estimate Statement to print and mail in by clicking HERE
There is also a good reference page with calculators at the Social Security site. Click HERE for that.