Adjusted Employer's ANNUAL Federal Tax Return or Claim for Refund
Form 944-X corrects a previously filed Form 944. Same structure as 941-X - standalone, one form per year corrected, adjustment process or claim process - for employers the IRS has placed on annual filing.
Whether you deposit monthly or semiweekly depends on your lookback period, not on this form. Publication 15 (Circular E) sets the rule, and it is worth checking each year - the schedule can change when your liability does.
IRS Publication 15The one matching the return you actually filed for that period. A year filed on 944 is corrected with 944-X, even if you now file quarterly.