If you and your spouse file separate returns and one of you itemizes deductions, the other spouse will have a standard deduction of zero. Therefore, the other spouse should also itemize deductions.

You may be able to claim itemized deductions on a separate return for certain expenses that you paid separately or jointly with your spouse. Deductible expenses that are paid out of separate funds, such as medical expenses, are deductible by the spouse who pays them. If these expenses are paid from community funds, the deduction may depend on whether or not you live in a community property state. In a community property state, the deduction is, generally, divided equally between you and your spouse. For more information refer to Publication 504, Divorced or Separated Individuals; and Publication 555, Community Property.

References:

• Publication 504, Divorced or Separated Individuals
• Publication 555, Community Property

Source: www.irs.gov