The current Trident system cost £12.6 billion to build (at 1996 prices) and £280m a year to maintain. Options for replacing Trident range from £5 billion for the missiles alone to £20–30 billion for missiles, submarines and research facilities. At minimum, for the system to continue after around 2020, the missiles will need to be replaced. The price of replacement of submarine has risen to £31 billion and it is estimated by Ministry of Defence that the cost of Trident replacement programme for 30 years to be at £167 billion.