To continue to be exempt from withholding for 2019, you must provide a new Form W-4 by February 15, 2019. If you do not provide a new Form W-4 by February 15, 2019, withholding will be based on the last Form W-4 that did not claim an exemption from withholding.
If one was not furnished, tax withholding will occur as if you are single with zero withholding allowances. If you provide a new Form W-4 claiming exemption from withholding on February 16 or later, it will apply to future wages but will not allow a refund of any taxes withheld while the exempt status was not in place.
