Leaving early or leaving others behind
A tenant who breaks a lease early often finds the landlord applying the deposit to rent for the period after move-out. New York now generally expects residential landlords to make reasonable efforts to re-rent the unit, which can limit what they may charge, though how that plays out depends on the facts. With several roommates on one lease, landlords typically hold the deposit until the whole tenancy ends, so a departing roommate's share is usually settled among the roommates. Sublets and assignments raise their own questions about who is entitled to the refund. Putting terms in writing with the landlord or roommates before you leave avoids many of these disputes.
Using the walk-through
Once you give notice that you are leaving, New York law generally lets you ask for an inspection before move-out, so you learn what the landlord considers damage while there is still time to fix it. Ask for it in writing, attend if you can, and keep whatever list comes out of it. Repairs made after the inspection should be photographed with dates. On the last day, photograph every room, return the keys in a way you can prove, and give a forwarding address in writing. These steps take an afternoon and can make any later disagreement much simpler to resolve.
When the refund falls short
If the deductions seem out of line, compare them with the inspection list and your photos item by item. Normal wear from living in a home generally cannot be charged, while damage beyond that can be. A short written response pointing out the gaps is a common first step, and small claims court is available if it does not settle things. Landlords sometimes raise unpaid rent from an early departure as an offset, which is where the lease terms and any re-rental effort become important. We can look over the lease and the deduction list and tell you which steps make sense for the amount involved.