The default: a lease ends when its term ends
A fixed-term lease is a contract for a specific period. When that period is up, the landlord generally doesn't have to offer you another one unless your state or city has a just-cause rule — the lease simply expires, and both sides are free to walk away. If your landlord decides not to renew, the main thing state law generally requires is proper advance notice that the lease won't continue, following whatever your lease or state law sets as the notice window. That's very different from an eviction: your landlord doesn't need "cause" to let a lease run out, in the same way you don't need a reason to decide not to renew a gym membership.
Where refusing to renew crosses into illegal territory
Even where a landlord doesn't need a reason, they can't have an illegal one. Refusing to renew because of your race, color, national origin, religion, sex, disability, or familial status violates the federal Fair Housing Act, which bars discriminating against a renter "in the terms, conditions, or privileges" of a rental because of these protected characteristics (42 U.S.C. § 3604). Some states and cities add more protected categories on top of the federal list — things like age, sexual orientation, gender identity, marital status, or source of income (including housing vouchers) are commonly covered locally even though they aren't in the federal statute. See can my landlord discriminate against me for more on how that works.
Retaliation is a separate problem
If your landlord decides not to renew shortly after you did something legally protected — filed a habitability complaint, requested repairs in writing, reported a code violation, or joined a tenant association — that timing can support a retaliation claim. Some states have their own retaliation statutes that specifically cover non-renewal, not just eviction, but the details (how long a "protected period" lasts, what you have to prove) vary by state, so check your state's landlord-tenant law or a local tenant rights organization for the specifics that apply to you. See can my landlord retaliate for filing a complaint for the fuller picture.
A few states limit non-renewal even without discrimination or retaliation
Some states go further and require a specific, legitimate reason before a landlord can end a month-to-month tenancy or decline to renew after a tenant has been there a while — often called "just cause" protections. Oregon is a concrete example: after the first year of occupancy, a landlord generally can't end a month-to-month tenancy without either a tenant-caused reason or a "qualifying landlord reason," such as intending to demolish or convert the unit, doing renovations that make it unsafe to occupy, moving in a family member, or selling to a buyer who will live there — each with its own notice period, some as long as 90 days (Or. Rev. Stat. § 90.427(3), (5)). Not every state has a rule like this, so check your own state's law rather than assuming it applies to you.
A concrete example
Say your one-year lease at $1,700 a month is ending, and your landlord tells you two months ahead of time that they've decided not to offer a renewal, with no reason given. Unless your state or city has a just-cause rule, that's within the landlord's rights as long as the notice was timely. Now say the same notice arrives one week after you sent a written complaint about a broken heater — the timing alone doesn't prove retaliation, but it's exactly the kind of fact pattern that supports a retaliation claim in states that recognize one.
Protecting yourself
If you think discrimination or retaliation is behind a non-renewal, write down the timeline: what you did, when, and when the non-renewal notice arrived. Keep every written communication with your landlord. You can file a housing discrimination complaint with HUD or your state or local fair housing agency — see how do I file a housing discrimination complaint for how that process works. Upload your lease to Honestkey to see your renewal terms and notice requirements laid out clearly before your term ends.