A month to month lease addendum converts a fixed-term tenancy into a periodic one, usually at the end of the term, without starting a new lease. It is the right instrument when both sides want to continue on the existing terms with flexibility about the ending. It is short, and four things have to be settled in it, because what an addendum leaves unsaid is decided by statute rather than by either party.
What changes, stated precisely
From a date, the tenancy continues month to month rather than for a fixed term. Say the date. Say that all other terms of the lease continue unchanged, and list anything that does not, typically the rent if it is changing at the same time. An addendum that says the tenancy becomes month to month and nothing else leaves both sides guessing whether the deposit terms, the pet permission and the parking allocation survived.
Notice, in both directions
State the notice period each side must give, within what the state allows, and how notice must be delivered. This is the whole point of the conversion and the clause most often omitted because the statutory default is assumed. Writing it down means the tenant knows too, which is what prevents the departure at two weeks' notice that neither the lease nor anybody's memory addressed.
Rent, and how it may change afterwards
If rent changes at the conversion, state the new figure and the first payment it applies to. Then state how it may change in future: by notice, on the statutory period, subject to any local cap. Landlords convert to month to month partly for this flexibility, and tenants agree to it partly not expecting it, so saying it plainly at the conversion is fairer and avoids the argument later.
The deposit and the documents carry over
Say so explicitly. The deposit already held continues to be held on the same terms, the inventory taken at the start remains the record of condition, and any addenda already signed continue. Where a state requires a fresh disclosure on a new tenancy, check whether a conversion counts as one, because that is the question a short addendum quietly skips.
Questions people ask about month to month lease addendum
Is an addendum better than a new lease?
For continuing an existing tenancy with the same parties and terms, yes: it is shorter, and it keeps the original lease and its inventory as the governing record.
What happens if nothing is signed at the end of a fixed term?
In most states the tenancy continues periodically by operation of law on terms the statute sets. That is a worse outcome than an addendum only because nobody chose it.
Does the deposit need to be re-taken?
No, and the addendum should say the existing deposit continues on the same terms so that nobody treats the conversion as a new tenancy.