"...The Internal Revenue Service has increased the cap on annual individual contributions to employer-sponsored retirement savings plans, including the Thrift Savings Plan, to $18,000 for 2015.
The increase, which tracks changes in the cost-of-living index, is the first since 2013, when the cap rose to $17,500 from $17,000. The limit applies to the combined total of contributions to traditional and Roth accounts..."