The 'Mean Girls' actress has to complete 480 hours of community work as part of her sentence for stealing a $2,500 necklace in January, but has so far only reportedly served 60 of the required hours, at the Los Angeles Downtown Women's Center.
A source told RadarOnline.com: "Lindsay has completed her shoplifters awareness class but is falling behind on her other commitments.
"Lindsay's team is telling her she needs to log significant time to show the judge that she is working towards completing her hours, but she is ignoring them. Lindsay's rationale is that she has a year to complete the service, so she isn't concerned about it right now."
The 25-year-old star has to complete 380 hours at the Women's Center and 100 hours at the Los Angeles County Morgue – which she has yet to start.
She is due for a progress hearing on October 17, and the source warns the judge handling her case "has told Lindsay in the past that she will not accept any excuses" for her not staying track.
Lindsay's publicist, Steve Honig, defended her recent appearances at model shoots and New York Fashion Week, saying: "Lindsay has been working very closely with her advisors to balance the demands of making a living while at the same time fulfilling her court-mandated obligations."
However, her father, Michael Lohan, has voiced his concern.
He said: "I am concerned about her community service at hand. Her lawyers and I have done all we can to keep her out of jail and the last thing in the world I want to see is her to get violated."