Can I claim my girlfriend as a dependent?

Maybe

According to nolo.com, you can claim your partner as a dependent if you meet five qualifications.

• Support: You must provide at least 50% of the support for the dependent partner.

• Residency: They must be a U.S. citizen or resident alien.

• Income: Their taxable income must be below $3900 (in 2013, up to $3950 in '14) --it's equal to the exemption amount--and you'll have to see whether the disability payments are taxable.

• Relationship: You can only claim them as a dependent if "the relationship does not violate local law". Nolo.com notes that such laws have been struck down recently where they've been challenged, so this soon may be no longer relevant.

• Marriage status: You can't claim a spouse as a legal dependent.