I, along with my siblings, received a $1836 "redemption due to death" from a John Hancock 403(B) account, that my father held until his passing in April of 2008. Is all or any of this distribution taxable on either my federal or state (Calif) returns?

Probably, because most 401(b) accounts are tax-deferred, NOT tax-exempt, which means the tax MUST be paid upon redemption.

Expect to get a Form 1099-R from John Hancock.