Specific to the purchase of health coverage, PEBB rules consider certain children as eligible dependents, and parents may purchase health insurance for their eligible children tax-free.  

Federal guidance limits eligibility for the tax benefit to the federal definition of “child,” which includes a son, daughter, stepchild, adopted child, or eligible foster child. PEBB eligibility includes some children who are not considered dependents for tax purposes, including children of domestic partners, grandchildren, nieces, and nephews, unless these children qualify as a dependent child or dependent relative per IRC 152 (c) or (d).
 
Read other FAQs on coverage for adult children