H.R.5475: To amend title 18, United States Code, to make a technical correction to ensure sex offenders who travel between States, regardless of when they traveled, must register with appropriate state and local authorities.

Sex Offender Mandatory Registration Act of 2008 - Amends the federal criminal code to: (1) apply registration requirements to sex offenders regardless of the date of their offense or the date of their travel in interstate commerce; and (2) make failure to register or update a sex offender registration a continuing offense for as long as such failure exists.