Is Water Purification FSA/HSA Eligible?

LETTER OF MEDICAL NECESSITY Date: [DATE] To Whom It May Concern, I am writing to certify that Water Purification is medically necessary for my patient: Patient Name: [PATIENT NAME] Date of Birth: [DOB] Diagnosis: [ICD-10 CODE AND DESCRIPTION] Medical Justification: Only if prescribed for specific medical condition. I have prescribed this item as part of the patient's treatment plan, and it is not for general health or cosmetic purposes. If you have any questions, please contact my office. Sincerely, [PHYSICIAN SIGNATURE] [PHYSICIAN NAME, MD] [PRACTICE NAME] [NPI NUMBER] [PHONE NUMBER]