If the output of your op-amp reaches as high or low as your power rail then that is as far as you can go with the output. This is called a rail to rail op-amp, and is expensive.
Typically an op-amp will only reach to within a certain voltage short of the full voltage. Typically this is within a volt for modern op-amps, but in the early days it used to be that within three volts was considered good.
So if you need a higher voltage output use a higher voltage power supply and an op-amp that can take that.