CHICAGO — Former U.S. House Speaker Dennis Hastert must report to a federal prison in southeastern Minnesota this week to begin serving a 15-month sentence in his hush-money case, one that revealed he sexually abused at least four boys decades ago when he coached wrestling at a suburban Chicago high school.

Hastert was the nation’s longest-serving GOP speaker, who for eight years was second in the line of succession to the presidency.

But when the 74-year-old man enters the prison gates, which he must do by Wednesday afternoon, he will be known to prison guards as Inmate No. 47991-424.

A look at what’s expected to happen in the coming days and what awaits Hastert, who will become one of the highest-ranking U.S. politicians in history to do prison time:

When and where

Hastert must show up at the Rochester Federal Medical Center by 2 p.m. Wednesday.

Inmates-to-be usually wait until just before the reporting deadline, but Hastert, who has been free on bond, could choose to report earlier to elude a crush of reporters and TV cameras.

U.S. District Judge Thomas M. Durkin recommended this facility for the ailing Hastert during sentencing on April 27, though the Federal Bureau of Prisons made the final decision. Hastert’s attorney, Thomas Green, confirmed it was the Rochester facility in an email.