Q: I intend to retire in July 2010. I would like to make maximum allowable contributions to my Thrift Savings Plan during that year. Is it legal/permissable to make the maximum yearly contribution allowed by IRS rules between January and July? Or must it be over a 12 month period?
A: The annual limits are not pro-rated. You may contribute the entire annual limit during a partial year of employment.
— Mike Miles