(1) Issuers that receive claims or send payments by electronic means shall, within one year after May 26, 1995 or the date on which the health care financing administration requires it of medicare intermediaries and carriers, whichever is earlier, accept the ASC X12N standard format or the national uniform billing data element specifications as developed by the national uniform billing committee for the health care claims submission transaction set (837) and send the ASC X12N health care payment transaction set (835) .