At least 4.4 million families in the United States are blended ones that include stepchildren and stepparents. For tax purposes, these "steps" receive preferential treatment as a result of their status because, on the one hand, they are treated as family members for many income tax benefit sections, but on the other hand, are excluded from the definition of family member for business entity attribution purposes and for gift and estate tax anti-abuse provisions. In the interests of fairness and uniformity, steps should be treated as family members for all tax purposes where they act like their biological or adoptive counterparts, regardless of whether such treatment would decrease or increase their tax burden.
Wendy C. Gerzog,
Families for Tax Purposes: What About the Steps?,
U. Mich. J. L. Reform
Available at: https://repository.law.umich.edu/mjlr/vol42/iss4/3