A guide to choosing the right entity, NPI type, tax ID and taxonomy code for each payer application so claims are not rejected.
Almost every enrollment problem in this area traces back to one question that was never settled: is the payer contract in your own name, or in your practice's name? Answering it once, at the start, prevents weeks of correspondence with the payer later.
This article is for practice owners and whoever handles your payer paperwork. Workspace admin access is not required.
Topics covered:
Individual and group enrollment compared
The identifiers each application needs
Taxonomy codes and why claims are denied without them
Correcting a tax ID a payer holds incorrectly
Frequently asked questions
Individual and group enrollment compared
The difference is who the payer is contracting with, and it determines who gets paid.
ENROLLMENT | CONTRACT IS WITH | PAYMENT GOES TO |
Individual | You personally | You, using your own NPI and tax ID |
Group | Your practice entity | The entity, with individual providers linked to it |
Note: if you have formed a company and want claims paid to the company, you need a group enrollment even if you are the only clinician in it.
The identifiers each application needs
Each of these has a defined place on a claim, and a mismatch in any of them is a common rejection cause.
NPI-1 (Required), the individual clinician's number, reported as the rendering provider
NPI-2 (Required for group billing), the organization's number, reported as the billing provider
Tax ID (Required), an SSN or EIN, matching the entity the contract is with. Both are types of taxpayer identification number
Taxonomy code (Required by many payers), identifies the provider's specialty and must match what the payer holds on file
Billing address (Required), must match your NPPES record for the same entity
PTAN, issued by a Medicare Administrative Contractor on Medicare enrollment only
Note: If you bill as a group you need both NPI types on the claim, NPI-2 as the billing provider and NPI-1 as the rendering provider.
Taxonomy codes and why claims are denied without them
Taxonomy is often described as optional. For a large share of payers, particularly Medicaid programmes, it is mandatory and a missing code is a hard denial.
Confirm the taxonomy code the payer holds for you. It must match their record, not just be a valid code.
Give us the code so it is applied to your billing profile.
Tell us if you hold one NPI across several payer enrollments, because taxonomy is what distinguishes them.
Important: Several Medicaid programmes require taxonomy on every claim, and some Medicare Advantage plans deny professional claims outright when the rendering provider taxonomy is missing. If you are enrolled with Medicaid, treat taxonomy as required.
Correcting a tax ID a payer holds incorrectly
This is a payer-side change, so it runs on their timeline rather than ours.
Send us the payer name and the tax ID they currently hold.
Confirm in writing which entity should be on the contract.
We contact the payer to request the correction and track it to completion.
Note: A tax ID correction typically takes several weeks. Claims submitted in the meantime may reject, so tell us if you would prefer we hold them until it is resolved.
Frequently asked questions
Do I need an EIN if I am a sole practitioner?
Not necessarily. Some sole proprietors bill on their SSN. You will need an EIN if you want claims paid to a company rather than to you personally.
Which taxonomy code applies to me?
It reflects your licence type and specialty. Confirm with each payer rather than assuming, because a valid code that does not match their record will still deny.
Can I be credentialed individually and bill as a group?
Only if the individual provider is linked to the group contract. Being credentialed alone is not enough for claims to pay to the entity.