The contractor has 90 days from the date of recording to file suit on the lien.
If he does not file suit within the 90 days the lien becomes void and you can force him to record a release of lien.
If he does file suit in the 90 days, you will need an attorney to help you resolve the dispute
San Francisco CA
This is NOT legal advice, just a general discussion of the law, as we are not familiar with the specific documents and facts of your case, etc. Please consult with a competent attorney in this area of the law for specific legal advice regarding your particular case, as the advice may vary depending on the facts.
You should send the contractor a letter explaining what is wrong with the bill and demanding that he release his lien, and keep a copy for yourself. If he still doesn't respond or release the lien, then you can wait out the 90 day lien to see if he files out. If he doesn't you can get an atty to file suit for you to get the lien off your property and he is liable for your reasonable attorney fees and costs. If he files suit to foreclose the lien you will also need an attorney but many don't file suit
Try and work the dispute out with the contractor. If you believe some of the amount claimed is due, then offer to pay that amount. If you cannot resolve it, then the next move will be up to the contractor.
He has 90 days from the date of the recording to file a lawsuit to enforce the lien. If he does not file the suit, his lien will not be valid and you could file a motion to have the lien removed.
If he does sue, you will want to discuss this with a local attorney.
If you're going to send the contractor a letter, you may wish to include a Release of Mechanic's Lien form along with it. These can be found fairly readily online, or an attorney may provide you with one.
Otherwise, yes, the ball is in the contractor's court for now. Your only obligation is to wait the 90 days to see if he acts to foreclose the lien in the form of a lawsuit.