Yes, you can claim your stepchild as a Qualifying Child dependent (filing as Married Filing Separate) if:
- The child must be related to
you. The child can be your son, daughter, stepchild, eligible foster
child, brother, sister, half-brother, half-sister, stepbrother,
stepsister, adopted child or an offspring of any of them.
- Your child must be under age 19
or, if a full-time student, under age 24. There is no age limit if your
child is permanently and totally disabled.
- Your child must live with you
for more than half the year, but several exceptions apply (ie. away at
school).
- The child cannot provide more
than half of his/her support.
- You must be the only person
claiming the child
- The child must be a US citizen,
resident alien, national, or resident of Mexico or Canada.
- The child cannot file a joint
return with his or her spouse.
See Rules For Claiming Dependents
