The post cited above by Unixken says "There is no federal law which describes the method of wearing military medals and decorations with civilian clothes. However, each of the military services have uniform regulations which cover this." The whole point of the original post is that "the Department of Veteran Affairs (VA) encourages all military veterans to wear their medals and decorations during Veterans Day (November 11th) and other patriotic holidays (such as Independence Day - July 4th, and Memorial Day - May 30th)..."

Military regulations (including uniform regulations) are enforceable under the Uniform Code of Military Justice -- a completely different jurisdictional authority than civilian law. Once a person is "separated from service" by discharge (retirees and commissioned officers can be a special case) they are no longer subject to the UCMJ.

There is, however a civilian federal law that might be applicable for at least certain kinds of military insignia: United States Code Title 18, Part I, Chapter 33, § 702 -- "Uniform of armed forces and Public Health Service: Whoever, in any place within the jurisdiction of the United States or in the Canal Zone, without authority, wears the uniform or a distinctive part thereof or anything similar to a distinctive part of the uniform of any of the armed forces of the United States, Public Health Service or any auxiliary of such, shall be fined under this title or imprisoned not more than six months, or both."

So, does the Department of Veteran's Affairs statement of encouragement cited above provide the requisite "authority" without which one would be in violation of 18 USC I, 33,702? Moreover, do service medals and decorations constitute a "distinctive part of the uniform?" -- Probably not, neither do chevrons, bars, stars, leaves or birds, but the EGA of the Marines certainly does, as does the crossed anchor and caduceus of the U.S. Public Health Service or the cap badges of any of the commissioned officers of the various services. Hmmmm....????