Use these envelopes to mail unfolded CMS-1500 forms to insurance providers. Envelopes feature window die-cuts that match the standard CMS-1500 forms address location so no need for separate addressing or labeling. Exterior reads "Please Do Not Bend," "First Class Mail" and "Insurance Claim Forms Enclosed." Closing the envelopes is quick and easy. Simply peel the strip and seal. The Health Care Finance Administration has changed its name to Centers for Medicare and Medicaid Services.