Several Maryland counties offer their own property tax credits or exemptions for veterans and surviving spouses, on top of the statewide disabled veteran exemption. What is available and who qualifies depends on the county.
Contact the Maryland Assessment Office for the county where your property is, ask what veteran credit or exemption that county offers, and apply through that office.
Your DD214, your VA rating documentation if the county credit depends on a disability rating, proof you own the home and live in it, and any county-specific form.