The answer to this question depends on the answer to two other questions:
- Is your spouse a U.S. citizen? and,
- Is the gift to your spouse a gift of a present interest or future interest?
Gifts to Citizen Spouses vs. Gifts to Noncitizen Spouses
If your spouse is a U.S. citizen, then due to the unlimited marital deduction you can gift any amount to your spouse without incurring any federal gift tax or state gift tax consequences as long as the gift is of a present interest.
If your spouse isn't a U.S. citizen, then you are given an annual exclusion from gift taxes for gifts of a present interest made to your noncitizen spouse. In 2011 the annual exclusion from gift taxes for gifts made to a noncitizen spouse was $136,000, this amount increased to $139,000 in 2012, and will increase to $143,000 in 2013.
Gifts of Present Interests vs. Gifts of Future Interests
In order for a gift to your spouse to qualify for either the unlimited marital deduction if your spouse is a U.S. citizen or for the annual exclusion from gift taxes if your spouse isn't a U.S. citizen, the gift must be of a "present interest" in the gifted property. In other words, you need to give the property entirely over to your spouse for his or her use, enjoyment and benefit, free from any strings attached.
Contrast this with a gift of a "future interest" - this is a type of gift with strings attached, meaning that your spouse won't have complete use and enjoyment of the gift until some future point in time. A gift of a future interest doesn't qualify for the unlimited marital deduction, the $13,000 annual exclusion from gift taxes for gifts made to nonspouses (the annual exclusion from gift taxes will increase to $14,000 in 2013), or the $139,000 annual exclusion from gifts taxes for gifts made to a noncitizen spouse (which will increase to $143,000 in 2013).
A common example of a gift of a future interest is reserving a life estate for yourself in a piece of real estate and then when you die your spouse will become the full and vested owner of the property. Another example is a gift made into a trust for the benefit of your spouse instead of giving the gift directly to your spouse - if your spouse doesn't have the immediate right to use, enjoy and benefit from the property gifted into the trust, then you've made a gift of a future interest to your spouse.
If you've made a gift of a future interest to your spouse, then regardless of whether or not your spouse is a U.S. citizen, the entire gift is taxable for gift tax purposes and must be reported to the IRS on Form 709, United States Gift (and Generation-Skipping Transfer) Tax Return.