01-24-2014 09:31 AM
Even if your husband does not work, it is not appropriate to claim him as a dependent. You would file Married Filing Jointly and you would take an exemption for both of you. If you are providing over half of your mother-in-law's support and she has lived with you all year, and no one else can claim her, then you can claim her as a dependent. Her social security income will likely not be taxable and won't count toward the $3900 threshold limit for a dependent.