The MTA's most recent prediction about the rehabilitation of the Smith Street-9th Street station on the F and G subway lines is that it will be completed by the end of the first quarter of 2013.
Until then, continue substituting the Carroll Street or 4th Avenue-9th Street station for Smith-9th. Use the B57 bus for connections between the Smith Street-9th Street station and the Carroll Street station (for the F and G) and the B61 bus for connections between the Smith Street-9th Street station and the 4th Avenue-9th Street station (for the F, G, and R).