At some point, The Powers That Be decided that superbills didn’t have enough information, so they decided to mandate use of printed paper claim forms. While things differed across the industry, larger insuers, Medicare, and Medicaid tended to insist on the new standardized forms.
The HCFA 1500 (left) was used to bill “professional” services such as doctor’s office visits, injections, lab services, and so on. Basically, anything that wasn’t a facility charge went here.
The UB-92 (below) was used to bill facility charges such as hospital bills, Skilled Nursing Facilities, Inpatient Rehab, etc.
These forms could be bought from a number of suppliers, and for some insurers, HAD to be red.
See, the advent of the new forms meant that they could be optically scanned, which was an improvement over typing in claims information. You fed a handful of claims into the scanner, the information was scanned and fed into the claims processing system, and WOOSH! a whole bunch of mundane work was done.
The problem with this, of course, was that the mailroom was still deluged in paper claims, and that you had to keep up the optical scanners, and you had to have people to run and fix them.
The next step was inevitable — using the computer to send claims.