SimplePractice Taxonomy Rejection: Rendering or Billing?
By George Ruan • October 7, 2026
Last reviewed: October 7, 2026.
A SimplePractice taxonomy rejection is about one of two fields: the billing provider taxonomy (box 33b) or the rendering clinician’s taxonomy (box 24J). For a group billing under a Type 2 NPI, the billing taxonomy is usually a group code, while the rendering taxonomy is the clinician’s own license specialty. Work out which field the rejection names, then fix only that one.
Sections
Which code goes where
Billing (box 33b). For a practice’s organization (Type 2) NPI, we tell practices to use 193400000X, Single Specialty Group, which fits a solo or single-specialty practice. 193200000X, Multi-Specialty Group, is for practices that span several specialties. Check that the code matches what NPPES shows for that NPI.
Rendering (box 24J). The clinician who saw the client, under their own individual NPI and their own taxonomy (for example, a counselor or clinical social worker code). It should match how that clinician is enrolled with the payer.
CMS’s taxonomy guidance points to the NUCC code set and notes that an NPI can list several taxonomy codes, with one marked primary.
Where to change it in SimplePractice
SimplePractice’s taxonomy guide separates the two, and notes some payers also need the ZZ qualifier in box 24I.
Billing taxonomy: Settings > Client billing and Insurance > Insurance billing > Default billing provider info.
Rendering taxonomy: the clinician’s Settings > Profile > Clinical info > Clinician details. SimplePractice says only the clinician can change it.
Overrides: check any claim rules that change billing details for a clinician or payer. Rules replaced the older billing profiles the taxonomy article still mentions.
The rendering taxonomy may not show on the onscreen claim but appear in the downloaded PDF, so check the PDF. If a required taxonomy or ZZ qualifier is missing there, ask SimplePractice support to check the payer’s setup with its clearinghouse.
When the taxonomy is right but the claim still fails
Taxonomy errors are often a symptom of an identity mismatch between the rendering and billing providers. In one case we worked, a Blue plan processed a client’s claims as out of network, even though the practice was in network, because it did not connect the rendering clinician’s NPI to the group’s billing NPI. The payer agreed the claims were processed incorrectly. Its first reprocessing attempt did not go through, and it eventually asked for a new claim. Expect that kind of fix to take several rounds, and tell the client not to pay the inflated amount on the explanation of benefits while it is open.
So before changing taxonomy codes, confirm the clinician is linked to the group with that payer. Do not switch to another clinician’s NPI or taxonomy to clear an edit.
Resubmitting
Test a newly prepared claim after any settings change. If the payer rejected the claim before accepting it, a corrected resubmission is usually enough. If the payer accepted and processed it, follow its correction or reconsideration process. SimplePractice warns that deleting a claim is permanent, so keep the original references. For entities that bill under different tax IDs, see claim rules for multiple tax IDs; for NPI basics, see how to apply for an NPI Type 2.
Related Guides
Frequently Asked Questions
What taxonomy should my group NPI use?
For most solo and single-specialty therapy practices, 193400000X (Single Specialty Group). Use the multi-specialty code only if the practice really spans several specialties.
Should the billing and rendering taxonomy match?
Not when a group bills for a clinician. The billing code describes the organization; the rendering code describes the individual who provided the service.
Can I put a supervisor’s NPI on the claim to fix a taxonomy error?
No. Change the rendering provider only if the wrong person was listed. Supervised billing depends on the payer’s own rules.
Sources
SimplePractice: Identifying your taxonomy code for claims
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