For years the Internal Revenue Service resisted the disclaimer of joint tenancy interests on the grounds that the disclaimer had to occur within nine months of the creation of the joint tenancy. IRS eventually came to accept the disclaimer of revocable joint tenancies within nine months after death and even more recently indicated that the Service would not resist the disclaimer of joint tenancy interests in other than revocable joint tenancies where there was a predeath right to sever the joint interests The focus on when joint tenancies could be disclaimed obscured the question of what could be disclaimed.