If my landlord return my security deposit, but I don't agree with the amount. Can I cash the check and still sue for the remaining amount?

Your question about  security deposits in Maryland raises a number of important issues that may be of broad general interest to readers of this site. I have been representing clients on both sides of these issues in Maryland and D.C. for over 20 years. Your posting is in D.C. but you note that you live in Maryland. I am admitted to practice in both jurisdictions. Generally, in Maryland, landlords must pay interest on residential security deposits but do not have to on commercial security deposits, depending on what they write in the lease. Maryland's Landlord and Tenant law is found in its Real Property article of the Maryland Code and can be found online. There are specific provisions on security deposits. THe broader question you ask is about whether it is "safe" to deposit the check, whether by depsiting the check you have agreed with the landlord that that is the amount of deposit return you are due, after any deductions for damage, unpaid rent, etc. The first inquiry might be whether the check has an "endorsement" on the back, Under something called the Uniform Commercial Code, adopted in both Maryland and D.C., if the Landlord has written "full and final payment" on the back of the check, that can be an agreement that you are not to receive any more money. Not as strong for the Landlord, but still a risk for you, is if there is similar language on the memo line on the front of the check or in a letter from the landlord (or even an alleged oral conversation with the landlord) that the check is payment for your security deposit. Of course, other factors can also intervene that would alter the above. This response is not intended to address all possible issues. This is at best a general overview. I encourage you, and all other readers, before you act (or decide not to take some action) to seek competent, local legal counsel who can address the specific facts of your particular situation. This web site and the responses herein, including this response,  are designed for general information only. The information presented at this site should not be construed to be  and is not formal legal advice. No attorney-client relationship exists and no attorney-client relationship is formed or created by this response or any response on this website. Furthermore, this does not represent the views or opinions of LexisNexis or its affiliated companies.