Not sure of your enrollment application status? You can check online with HHH Medicare Administrative National Government Services. On the NGSMedicare.com website, you can find the Provider Enrollment Status Inquiry Tool under the Provider Resources tab under Calculators & Tools, the MAC tells providers. How to do it: You can enter the valid case number, and click the Submit button, NGS instructs. Or you can enter a valid National Provider Identifier (NPI), and Tax Identification Number (TIN) combination, and click the Submit button.