Massachusetts is a tenant-protective state with a famously technical security deposit statute. General Laws Chapter 186, Section 15B caps the deposit at one month’s rent, requires it to sit in an interest-bearing account, demands a return within 30 days with an itemized statement sworn under penalty of perjury, and punishes mistakes with forfeiture or treble damages. The same statute limits “last month’s rent” to one month’s rent and bans key money.
The state’s lead law (G.L. c. 111, § 197) adds a layer few other states have: pre-1978 units housing children under six must be deleaded or under interim control, with a Certificate of Compliance or Letter of Interim Control on file. Rent control has been banned statewide since 1994, and a 2022 Boston ballot question to bring it back failed.
Cities add their own rules — Somerville and Cambridge have just-cause eviction protections, and Boston runs eviction-prevention and right-to-counsel programs for income-eligible tenants. This guide covers the state rules that drive most disputes. It is general information, not legal advice.
| Governing law | M.G.L. c. 186 (plus c. 111 § 197 for lead) |
|---|---|
| Security deposit cap | 1 month’s rent (c. 186 § 15B) |
| Deposit return deadline | 30 days after vacating, with itemized statement sworn under penalty of perjury |
| Deposit interest | 5% or the bank’s rate, whichever is less, paid yearly |
| Wrongful withholding penalty | Up to 3× the amount wrongfully withheld + attorney’s fees |
| Nonpayment notice to quit | 14 days (c. 186 § 11) |
Massachusetts Rental Law at a Glance
Chapter 186 covers estates for years and at will — the technical names for fixed-term leases and month-to-month tenancies — and Section 15B is the deposit statute everyone argues about. Evictions proceed as summary process actions in Housing Court or District Court, with strict notice rules on the front end.
Two things make Massachusetts different. First, deposit rules are enforced with teeth: courts routinely award treble damages for deposits mishandled in bad faith. Second, the lead law imposes an affirmative duty to make pre-1978 housing lead-safe for young children — not just to disclose a hazard. A generic national lease that ignores either layer will not survive contact with a Massachusetts court.
Security Deposits: The One-Month Cap and the Paperwork Trap
Under G.L. c. 186, § 15B, a landlord may collect no more than one month’s rent as a security deposit, and no more than one month’s rent as last month’s rent, on top of first month’s rent and the cost of a key and lock. Key money — any other upfront payment — is prohibited. The deposit must sit in a Massachusetts bank in an interest-bearing account, separate from the landlord’s own funds.
Within 30 days of the tenant vacating, the landlord must return the full deposit with accrued interest or send an itemized statement of damages — sworn under penalty of perjury — with the balance. The statement must be specific: each damage, the repairs needed, and written evidence such as estimates, bills, or receipts. Tenants must also get a written condition statement when the deposit is collected and a receipt naming the bank. Massachusetts sets no separate cap on pet deposits, but courts have treated pet deposits as security deposits subject to Section 15B’s one-month cap and interest rules — label any pet money carefully.
- ✓Interest: if the deposit is held a year or more, the landlord pays the lesser of 5% or the interest the bank actually paid, on the lease anniversary, and reports the bank name, account number, and interest in writing.
- ✓If the tenancy ends before the anniversary, accrued interest is due with the deposit within 30 days of termination.
- ✓Failure to return the deposit, provide the itemized statement, or transfer it to a successor owner can mean forfeiture of the right to keep it, or liability for up to three times the amount wrongfully withheld, plus interest, attorney’s fees, and costs.
- ✓Practical tip for tenants: photograph the unit at move-in and move-out. For landlords: every deduction needs a real invoice and a sworn statement — Massachusetts judges read Section 15B literally.
Rent Increases and the Rent-Control Ban
Massachusetts has no rent control anywhere. The statewide ban dates to a 1994 ballot initiative, and only Boston may re-adopt rent control by local vote — Boston voters rejected that in 2022. There is also no statute setting a specific rent-increase notice period; the lease governs, and for month-to-month tenancies the common practice is at least 30 days’ written notice, matching the rental period.
Tenants receiving an increase should confirm it is in writing and check the lease for the notice period. Landlords should send increases in writing with enough notice and keep proof of delivery — an oral increase on a month-to-month tenancy is a classic source of avoidable disputes. Some cities are also considering local rules, so monitor your municipality.
The Lead Law and Other Disclosures
The Massachusetts Lead Law (G.L. c. 111, § 197) requires that any dwelling built before 1978 where a child under six will live be deleaded or covered by an interim-control letter, with a Certificate of Compliance or Letter of Interim Control issued by the state. The federal lead-based paint disclosure applies to the same housing, and the state law carries strict liability: landlords can be sued for lead poisoning without proof of negligence.
Massachusetts also requires smoke detectors and carbon monoxide alarms in rental units, and many cities require a fire department certificate of compliance before a unit can be re-rented. There is no statewide mold or bed-bug disclosure requirement, but a landlord who knows about a serious condition and stays silent can still face liability, so a well-drafted lease documents known conditions up front.
Repairs and the Warranty of Habitability
Massachusetts courts read an implied warranty of habitability into every residential lease: the unit must be fit for human occupation, with working heat, water, electricity, and safe structural conditions. When a landlord fails to fix a serious condition after written notice, tenants have real remedies — rent withholding and abatement are recognized when done through the right procedures, and Housing Court judges know these defenses well.
There is no broad statutory repair-and-deduct in Massachusetts, so tenants who withhold or deduct rent should follow the notice rules carefully and keep every record; the safer path is often a written repair demand followed by a rent escrow or court action. Landlords should treat any written repair request as a deadline event — an unanswered request can turn a routine eviction into a counterclaim for abatement plus fees.
Evictions: Summary Process and Notice to Quit
Every Massachusetts eviction starts with a written notice to quit. For nonpayment of rent, the notice must give the tenant at least 14 days (c. 186, § 11). For no-fault termination of a month-to-month tenancy, the landlord must give written notice at least a full rental period — typically 30 days — in advance. Lease violations follow the lease and the applicable statute.
If the tenant does not leave, the landlord files a summary process action in Housing Court or District Court. The tenant’s answer must be filed on time — a missed deadline can produce a default judgment and a warrant of execution, after which only a sheriff or constable may remove the tenant. Tenants facing eviction should contact Greater Boston Legal Services, a local tenant organization like City Life/Vida Urbana, or the state Attorney General’s landlord-tenant resources immediately.
Local Protections and Resolving Disputes
Local rules change what state law alone provides. Somerville’s tenant-protection ordinance adds just-cause limits and additional notice or relocation requirements, Boston funds eviction-prevention services and a right-to-counsel program for income-eligible tenants, and Cambridge has its own protections. Tenants should check the city as well as the state.
Deposit disputes under $7,000 can be filed in small claims court (c. 218, § 21), with Housing Court available for larger or habitability-related claims. Start with a written demand letter, then file where the property is located. MassLegalHelp and Greater Boston Legal Services publish plain-language guides and form letters, and Massachusetts courts are generally friendly to self-represented tenants who come prepared with documents.
Guide reviewed 2026-08-19. Rental laws change frequently; verify the current statute text before relying on any rule on this page. This information is not legal advice.