If someone was sentenced 240 months in prison followed by 84 months sis how many months will they actually serve?

If someone is sentenced to 240 months in prison followed by 84 months of supervised release (sis), they will serve the full 240 months in prison. The 84 months of supervised release occurs after they have completed their prison sentence, so they will serve a total of 240 months in prison, followed by an additional 84 months of supervision, but not in prison. Thus, the actual time served in prison is 240 months.