The Office of Fusion Energy Sciences (FES) of the Office of Science (SC), U.S. Department of Energy (DOE), announces its interest in receiving new or renewal grant applications for theoretical and computational research relevant to the U.S. magnetic fusion energy sciences program. Applications selected in response to this FOA will be funded in Fiscal Year 2015, subject to the availability of appropriated funds. The specific areas of interest are: 1. Macroscopic Stability 2. Confinement and Transport 3. Boundary Physics 4. Plasma Heating & Non-inductive Current Drive, and 5. Energetic Particles Specific information about each topical area is included in the Supplementary information section of the full Funding Opportunity Announcement (FOA) document. Due to the limited availability of funds, Principal Investigators with continuing theory grants may not submit a new application in the same topical areas as their existing grant. A Principal Investigator may submit only one application in response to this FOA, but applications can target multiple topical areas. Multiple applications from the same institution are allowed, subject to the above constrains. The full text of the FOA is located on FedConnect. Instructions for completing the Grant Application Package are contained in the full text of the FOA which can be obtained at: https://www.fedconnect.net/FedConnect/?doc=DE-FOA-0001102&agency=DOE.