Properly registered businesses must comply with state and federal requirements. A doctor is no different and should have a Federal Tax Identification Number (TIN) issued by the Internal Revenue Service. The TIN is required for doctors to conduct normal business activities, such as pay business taxes, bill insurance providers and process payroll. There are several ways to find a doctor's TIN, but being a private entity, there is no guaranteed way to find it.

Ask the Doctor's Office

There is no reason a doctor would withhold TIN information if there is a viable business need. Call the doctor's office and ask to speak with the business manager. This person helps the doctor run all administrative aspects of his business. Identify yourself to the business manager and explain the need for the TIN. It is possible that the information won't be disclosed if the need isn't deemed credible or necessary. Because it is a private business's tax number, gatekeepers will protect it in the same way personal Social Security numbers are protected.

Payroll Documents

Employees and former employees need the TIN, also referred to as the Employer Identification Number (EIN), to file personal taxes. This information is located on pay stubs and on W2 forms sent by all employers to employees in January of the year following the tax year.

Employees can also find this information when using tax preparation software if they have all other pertinent business information. Tax preparation software such as TurboTax or H&R Block have a search system for tax filers to electronically access W2 forms. Enter the required business entity name and address to see if the information populates.

Look at Past Bills

Patients might need doctor TIN information when calling insurance carriers. If you're unable to reach the doctor to get the information, look at old medical bills. The TIN is often located on the bill and is another resource for patients to get information quickly.

Search Provider Networks

Most doctors have additional identifying numbers for the business called Provider Identification Numbers. Any doctor providing Medicare services also must register using the TIN. Provider databases allow users to search via name and location or TIN. Obviously when seeking the TIN, search by name. This method requires knowing which provider network the doctor belongs to. If the doctor is not in an insurance provider's network, this search will not yield the desired TIN information.


Doctors who have lost their EIN can verify the information directly with the IRS. Authorized representatives can call the Business and Specialty Tax line at 800-829-4933. Hours of operation are 7:00 a.m. to 7:00 p.m. Monday through Friday.