My aunt and uncle have multiple Rental homes. My uncle recently passed away and my aunt wants to know if she can start deprecation over? And the tax basis?

Nope.

@Sean Rogers What state did they live in and where are the properties? Did they own the properties jointly (or as tenancy by the entirety)?

States that follow common law (which are most states), your aunt could potentially get a step up in basis to fair market value for 1/2 of the property, and as such, "re-starting" the depreciation on that 1/2.

My recommendation: Get with a CPA who can help you navigate the complexities of income and estate tax laws. The step up in basis can potentially save you thousands of dollars.

Originally posted by @Sean Rogers :
My aunt and uncle have multiple Rental homes. My uncle recently passed away and my aunt wants to know if she can start deprecation over? And the tax basis?

Consult with your CPA, but to my understanding, as long as the properties were owned jointly, there will be a 50% step-up in basis based on fair market value. Assuming the properties have appreciated since they were purchased, this can be a significant increase in deductions. 

If the properties are in the following states, then your Aunt can take a 100% step-up in basis based on fair market value: Arizona, California, Idaho, Louisiana, New Mexico, Nevada, Texas, and Washington, Wisconsin. This weird-but-true rule means that one can sell assets inherited from their spouse and only owe federal capital gains tax on the post-death appreciation, if any. (Source: Internal Revenue Code Section 1014(b)(6).)

The properties are all in TN. They were owned jointly.

@Sean Rogers

Let's go through an example.  

Your aunt and uncle are cowoners of a rental property they bought several years ago for $50K.   Since the property is jointly owned, your aunt's basis in her half of the property is $25K and your uncle's tax basis is also $25K.  On the day your uncle passed away, the property was worth $150K.  Your uncle's half of the property is worth $75K but only $50K of that is the stepped up basis that your aunt inherited.

If the property remains in service as a rental, your aunt can begin depreciating this $50K inherited stepped up basis on a new 27.5 year depreciation schedule.  She would continue depreciating the original basis on the current depreciation schedule.