tˈɛndˈɪdʒɪt ˌɛnpˌiːˈaɪ nˈʌmbɚz mˈeɪ biː vˈælᵻdˌeɪɾᵻd jˈuːzɪŋ ðə lˈuːn ˈælɡɚɹˌɪθəm baɪ pɹˈiːfɪksɪŋ "ˈeɪɾi θˈaʊzənd ˈeɪthˈʌndɹɪd fˈoːɹɾi" tə ðə tˈɛndˈɪdʒɪt nˈʌmbɚ.
Ten-digit NPI numbers may be validated using the Luhn algorithm by prefixing "80840" to the 10-digit number.