In most jurisdictions, a rental agreement or a lease continues to be valid, regardless as to whether the property changes hands. Any new homeowner is required to honor lease terms. Additionally, many states and municipalities make it compulsary for landlords to give tenants written notice of a sale of property or any changes in ownership.
If you're renting a home, there's always a chance the owner might sell it. If this occurs, the homeowner is required to give you notice of the sale in most states; this is true of rental homes and apartments. If your state doesn't require the homeowner to notify you of a pending sale, you're typically entitled to a notice of a rent increase or lease termination.
Renter's Rights and Raising Rent
If you have a lease that's month-to-month, the new landlord can raise your rent, provided you are given adequate notice. In many states, if a tenant has a month-to-month lease, the landlord is required to give a 30-day notice of a rent increase. However, if a tenant signed a one-year lease, and has only lived in the rental unit for six months, the landlord cannot raise the rent until the one-year period is reached. It's true, however, that most states have no cap on how much a landlord can raise the rent. Typically, the only restiction is on the amount of notice a landlord must give. This doesn't apply to rent-controlled units.
In 2009, Congress passed the Protecting Tenants at Foreclosure act. This act protects tenants from being evicted by new homeowners after a foreclosure. Pursuant to the act, tenants can stay in their rental units until their lease expires; tenants who have month-to-month tenancies are entitled to a 90-day notice if the new homeowner wishes to terminate the lease.
Each state has it own specific landlord-tenant laws. As such, you should know your particular state's laws and how those laws apply to ownership transfer of rental properties. It's important to note that most states allow for rent increases for month-to-month tenancies, as long as the prescribed amount of notice is given. If you have a lease under which you and your landlord agreed on a specific price for a set amount of months (usually 12 months), the new homeowner/landlord has to honor it, and by extension, refrain from raising your rent.