Miller trust and federal income tax question...

A Miller Trust is being set up and funded. Regulations say that the only deductions that are allowed from the gross income of the institutionalized spouse are for medical insurance premiums. What about federal income tax that is withheld from a pension? We were told to stop the withholding (which was done), but should the federal income tax that was already withheld for the first month of the Miller Trust be reimbursed to the trust by using the community spouse's funds?