Spouses do not claim each other as dependents on their tax returns. Rather, if both spouses agree, they can filing a return under the status "married filing jointly". This is how the federal tax return works; the state tax return likely is similar.
Filing together, the spouses would usually get two tax exemptions. Depending on their ages and disability, the spouses may be able to claim a higher standard deduction.
Depending on the specific facts, sometimes it is better for a married couple to file tax returns under the status "married filing separately".
You should review your specific facts with a tax professional (an Enrolled Agent, CPA, attorney) as the answers depend on your specific facts.
As a married couple you have two choices in filing - either married filing jointly, or married filing separately. You can not claim him as a dependent. Have your tax preparer run the numbers as filing separately and jointly to see what yields the best result.
Any individual seeking legal advice for their own situation should retain their own legal counsel as this response provides information that is general in nature and not specific to any person's unique situation. Circular 230 Disclaimer - Advice given in this response cannot be used to eliminate penalties with the IRS or any other governmental agency.