inheritance for illegitimate child

What is the name of your state (only U.S. law)? California

My cousin is the illegitimate child of a wealthy business man in failing health. He has three siblings who are legitimate. The wealthy business mans wife has set up a trust to manage their assets. Does this prevent my cousin from benefiting as a rightful heir as the three legitimate children when his father dies?

Please have your cousin come here and set up his own account, as he should really be the one asking these questions, and only he will have all the information needed.

In probate, the legal children, of the marriage or not of the marriage, only inherit those assets that are left to them, if a will, and which belong to the decedant's estate. Assets that pass outside probate are not part of the "estate". It is not unusual for spouses to leave the bulk of their holdings to each other, espercially those they may have accrued together over a long term marriage..

But there could be a problem if the illegitimate child is not written into the will. With an inclusion, even if in merely some minimal manner, it shows the father intended to treat the illegitimate child as he as. If the illegitimate child isn't mentioned at all, that child may be able to dispute a will based on the appearance he may have forgotten or not been aware of the child. As such, the claim would be that the father would have included the child had he known about her/him.

There are too many unknowns here to be assuming that your cousin is a “rightful heir”. That is, if by that expression you mean he or she is an heir-at-law legally entitled to inherit.

Because unless the purported father has acknowledged paternity or the filiation has been judicial decreed or the cousin is provided for by the father’s will, he or she is not an heir in that sense.

Nor could the cousin be treated as a pretermitted child and take by intestate succession were the filiation to have been established or the blood relationship formally acknowledged. He or she would have to be born subsequent to the date of the man’s will.

Then of course, if the will expressly disinherits the child he or she has no rights of heirship regardless.