Lohan was accused of lying by saying someone else was driving her Porsche when she was involved in a Santa Monica, Calif., car crash last June. She is on probation after stealing a necklace and driving drunk.
The 26-year-old actress was ordered to 90 days in rehab and will avoid jail time as part of Monday's plea deal, TMZ reported.
She also was ordered to perform 30 days of community labor, submit to drug testing and undergo psychotherapy for 18 months, the celebrity news website said.
TMZ said the former child star was nearly 50 minutes late to her court hearing.
Best known for her hit films such as "The Parent Trap," "Freaky Friday" and "Mean Girls," Lohan has seen her career eclipsed in recent years by her legal woes and battles with drug and alcohol addiction. She was most recently seen in the critically panned TV movie "Liz & Dick."