Normally the IRS has 10 years from the date of assessment to collect on the tax debt due. However, it starts as of the date of assessment which means, if you file late, the statute runs from the date the IRS assesses the late filed return.
Also, there are many actions that extend the CSED date. Here are some of these actions:
Form 900- Waiver of the CSED
Assets in Custody of the Court that prohibit levy
Taxpayer Assistance Order (TAO)
Offer in Compromise
Wrongful Seizures that are returned to the taxpayer
Collection Dur Process hearings
Each of the above above have different rules and effects on the CSED. You can ask the IRS directly for the CSED date. If you have any questions on the CSED, you should consult a tax expert.