I'm going to inherit some property in Missouri. Could I possible avoid estate taxes if add my wife and brother as co-owners, instead of putting them in my will?
Estate taxes are based on the total value of the estate of the person who died, not on the individual asset value. Adding someone to the title of the asset at this point doesn't change whether there were taxes due from the estate of the person who left the property to you. If your total estate is greater than $1 million, you should consult with an estate planning attorney about options for your estate to avoid taxes (and probate) at your death. (The estate tax exemption is $5 million this year, but that may or may not be extended beyond this year.)
Always remember that adding any co-owner reduces your control of the real estate and should only be done, if at all, after careful consideration of the potential consequences.
This answer is for informational purposes only and should not be considered specific legal advice, nor does it constitute an attorney-client relationship.
In addition to Attorney Finch's answer, your adding someone to the title may cause gift tax issues during your lifetime. You should consult with an estate planning attorney and review your entire situation, in light of your inheritance, to determine your best course of action. Attorney Finch appears to be in your area. You might consider contacting her for a consultation. There is no reason you cannot do this, now, although you may need to adjust your estate plan, once you receive the property.
*** LEGAL DISCLAIMER I am licensed to practice law in the State of Michigan and have offices in Wayne and Ingham Counties. My practice is focused in the areas of estate planning and probate administration. I am ethically required to state that the above answer does not create an attorney/client relationship. These responses should be considered general legal education and are intended to provide general information about the question asked. Frequently, the question does not include important facts that, if known, could significantly change the answer. Information provided on this site should not be used as a substitute for competent legal advice from a licensed attorney that practices in your state. The law changes frequently and varies from state to state. If I refer to your state's laws, you should not rely on what I say; I just did a quick Internet search and found something that looked relevant that I hoped you would find helpful. You should verify and confirm any information provided with an attorney licensed in your state.