The federal government go by federal sentencing guidelines. Usually if the defendant admits their guilty and show responsibility for their actions, the judge could run the sentences concurrently.

However if you take your case to court and lose, the judge can sentence you consecutively and in extreme cases do an upward departure from sentencing guidelines.

Theoretically, Avenatti could be facing 300 years. He would never get 300 years though or even 100 years. Federal sentencing guidelines might recommend 7 1/2 to 8 years. He may also be convicted in the tax case and fraud/extortion from his client Stormy Daniels. The federal judge could run his time concurrently or consecutively. It's a difference of ten years or more.

Obviously, Michael Avenatti deserves the maximum possible sentence.