Massachusetts Security Deposit Law
What landlords in Massachusetts need to know about deposit limits, refund deadlines, interest, and penalties for getting it wrong.
Deposit cap
1 month's rent
Refund deadline
30 days
Interest required?
Yes
5% annual simple interest (or the rate actually earned in an interest-bearing account) is required.
Separate account?
Yes
Penalty for noncompliance
Noncompliance (no separate account, no receipt, no interest) can result in treble damages plus attorney's fees.
Statute: Mass. Gen. Laws ch. 186, § 15B
This page summarizes general state-level rules as of 2026 and does not cover city or county ordinances, which can be stricter. Verify against the statute cited above or with a local attorney before relying on it. See all states.