wˌɛn fɪzˈɪʃənz kænˈɑːt bˈɪl fɚɹə sˈɜːvɪs, ɪt sˈɜːvz æz ɐ dˌɪsɪnsˈɛntɪv tə pɚfˈɔːɹm ðæt sˈɜːvɪs ɪf ˈʌðɚ bˈɪləbəl ˈɑːpʃənz ɛɡzˈɪst.
When physicians cannot bill for a service, it serves as a disincentive to perform that service if other billable options exist.