The Navy's proposed FY2015 budget requests $1,219.3 million for continued research and development work on the Ohio replacement program (ORP), a program to design and build a new class of 12 ballistic missile submarines (SSBNs) to replace the Navy's current force of 14 Ohio- class SSBNs. The Ohio replacement program is also known as the SSBN(X) program. The Navy has identified the Ohio replacement program as its top program priority.