DOT follow up testing occurs when an individual has violated the drug and alcohol testing rules. The amount of follow-up testing you receive is determined by a Substance Abuse Professional (SAP) and may continue for up to 5 years. This means the SAP will determine how many times you will be tested (at least 6 times in the first year), for how long, and for what substance (i.e. drugs, alcohol, or both). Your employer is responsible for ensuring that follow-up testing is conducted and completed. Follow up testing is in addition to all other DOT required testing and all follow-up tests will be observed.