A Guide to Modifiers for Psychotherapists
Let’s say you saw a parent alone to discuss their child during one session (90846) and then saw the child client in a session with the parent later that afternoon (90847). Same day, same diagnosed client involved in the billing, but two very different pieces of clinical work. You bill both. Two weeks later, the payer sends back a denial because, as far as their system can tell, you billed the same client twice for the same date of service. Nothing about your clinical work was wrong. The problem lived in one small, easy-to-miss field: Item 24d, and the two-digit modifier that never made it onto the line.
What Is A Modifier?
A modifier is a two-digit code that, you guessed it, modifies the meaning of the service or procedure, indicated by the CPT® code, by giving additional details about it (American Academy of Professional Coders [AAPC], 2025). There are two kinds of modifiers, though. One just provides additional information, but the other actually changes the reimbursement rate for the service coded.
Basically, you may be anticipating a denial or a certain reimbursement from an insurance payer for one reason or another, so you’re providing a two-digit explanation for why they shouldn’t deny the claim and/or why they should reimburse differently for that claim (American Medical Billing Association [AMBA], 2025).
CPT® codes tell the payer what kind of session took place (AMBA, 2025). Modifiers tell the payer the specific circumstances around the service:
whether a session ran alongside another service,
happened by phone instead of video, or
needed to be flagged as distinct from something else you billed that same day.
Leave that detail off, or place it incorrectly, and a perfectly legitimate session can come back denied by the insurance company.
This post picks up where our last one left off. To brush up on your CPT® codes, read Understanding Mental Health CPT® Codes. For now, let's turn to modifiers, because this is where a lot of clean clinical work runs into billing trouble.
What a Modifier Does
Again, a modifier is a two-digit code attached to a CPT® code to explain a circumstance that changed how the service was delivered (or reimbursed), without changing what the service fundamentally was (AAPC, 2025). Think of the CPT® code as the headline and the modifier as the footnote that keeps the headline accurate.
Modifiers generally fall into two buckets:
Modifiers that affect reimbursement. These can change how much a payer pays, or whether they pay at all (AMBA, 2025).
Modifiers that are informational only. These clarify something about the service but do not change the payment (AMBA, 2025).
Common Modifiers Psychotherapists Use
As a psychotherapist or counselor, you won’t need every modifier listed in Appendix A of the CPT® book. In practice, a small handful covers almost everything a therapist bills (American Medical Association [AMA], 2026).
Modifier 59: Distinct Procedural Service
This modifier signals that a procedure or service was distinct or independent from other services performed on the same day (AMA, 2026). In a therapy context, it often comes up when a client is seen twice in one day for genuinely separate reasons (Williams, 2026). For example, a 90846 "family only" session in the morning followed by a 90837 individual session in the afternoon might use the 59 modifier on the second claim line to show the payer that these were two distinct sessions, not a duplicate billing error (Williams, 2026). The same modifier 59 would address the 90846 + 90847 scenario from the introduction as well.
If your caseload includes same-day sessions like this, it is worth a direct conversation with your specific payers to discover how they prefer you code this on a claim, as different payers may vary in their coding or claim guidelines.
93 and 95 Telehealth Modifiers
These two get confused constantly, so it is worth committing the distinction to memory:
93: Synchronous telehealth by audio only (a phone call), and
95: Synchronous telehealth by audio and video (AMA, 2025).
Getting the modifier right is only half the job. The place of service (POS) code has to match:
POS 02: Telehealth delivered somewhere other than the patient's home, and
POS 10: Telehealth delivered while the patient is in their own home (Centers for Medicare and Medicaid Services [CMS], 2024).
A mismatch between the modifier and the POS code is a common, avoidable reason for a telehealth claim to bounce back. For example, if you use POS code 11, indicating the session took place at the clinician’s office, but pair that code 11 with a 93 or 95 telehealth modifier, the claim will come back since the codes contradict each other. If you’re billing Medicare, they may not want any modifier attached at all and only want a telehealth POS code, so it’s worth verifying both the POS preferences and telehealth modifier codes accepted with the payer.
License-Level Modifiers for Psychotherapists
These matter most for state-run Medicaid programs, which often want to know the credential of the person providing the service (AMBA, 2025). Always confirm with each payer, since requirements vary, and many Medicaid plans also want a corresponding taxonomy code in addition to the modifier (CMS, 2026).
AH Clinical psychologist, doctorate level (PhD or PsyD)
AJ Licensed Clinical Social Worker (LCSW)
HE Mental Health Program
HJ Employee Assistance Program (EAP) visit
HN Bachelor's degree (BA, BS)
HO Master's level (MA)
HP Psychologist, doctorate level (PsyD or PhD)
(AMA, 2026)
Frequently Asked Questions
What modifier do I use for a telehealth therapy session?
It depends on how the session happened and the specific payer’s claim guidelines. Usually, use 95 for a session held by audio and video together, and 93 for a session held by phone only, with no video (AMA, 2025; AMBA, 2025). Pair whichever modifier you use with the correct place of service code: 02 if the client was somewhere other than home, or 10 if they were in their own home (CMS, 2024).
Keep in mind that Medicare no longer requires modifier GT on professional claims for telehealth services (Verhovshek, 2018). Instead, CMS says using POS code 02 alone certifies the service meets telehealth requirements (Verhovshek, 2018).
Also worth knowing is that although the AMA introduced modifier 95 (synchronous telemedicine service) in 2017, Medicare doesn't recognize it (Verhovshek, 2018). If you're billing other payers for telehealth, check their specific guidelines before choosing a modifier (Verhovshek, 2018).
How many modifiers can I enter in Box 24d?
Most versions of the CMS-1500 form allow up to four two-digit modifiers per line (National Uniform Claim Committee [NUCC], 2025). In practice, therapy claims rarely need more than one or two. If you do enter more than one, put the modifier that most directly affects payment first, since some payers only process based on the first modifier listed (Healthy Connections Medicaid, 2015).
Can I bill two therapy sessions for the same client on the same day?
Sometimes, if the sessions are genuinely separate and serve different purposes, such as a family session in the morning and an individual session in the afternoon (CMS, 2026). This is the kind of situation where a modifier like 59 may come into play on the second claim line, though payer policies vary enough that it is worth confirming directly with each one before you count on it being accepted (Williams, 2026).
Do I need a modifier for a 90837 session that runs longer than 53 minutes?
No. There is no modifier or separate code for sessions beyond 53 minutes. A 90-minute session and a 55-minute session are both billed under 90837, since the code represents an open-ended floor rather than a fixed bracket (AMA, 2026).
What is a GA modifier used for in mental health billing?
The GA modifier is specific to Medicare and signals that you expect a service to be denied as not reasonable and necessary, and that you have a signed Advance Beneficiary Notice (ABN) on file to cover that possibility (AMBA, 2025). If you expect the same kind of denial but do not have a signed ABN on file, GZ is the modifier to use instead (AMBA, 2025).
Why do some Medicaid claims need a license-level modifier?
Several state Medicaid programs use license-level modifiers to identify the credential of the person who delivered the service, such as AJ for an LCSW or HO for a master's-level clinician (AMBA, 2025). Not every payer requires this, so it is worth confirming directly with each Medicaid plan you bill, since many also expect a matching taxonomy code in addition to the modifier code (NUCC, 2025).
It’s a Wrap on Mental Health Modifiers
Modifiers exist so that the small, real complications in your clinical work, like a session split across two purposes in one day or a telehealth call by phone instead of video, show up accurately in the record and get paid accurately in return. The modifier codes themselves are simple once you have used them a few times. What takes more care is matching the modifier to what actually happened in the room and checking each payer's specific rules before you assume they all work the same way.
When in doubt, a call to a payer's provider line will save you far more time than an appeal after a denial. Learn more about calling the provider line at How to Verify Mental Health Benefits by Phone.
References
American Academy of Professional Coders. (2025). Coding and medical necessity [Online course]. In Medical billing training: Certified professional biller (CPB)®. Coursera. https://www.coursera.org/learn/cbp-coding-medical
American Medical Association. (2025, March 7). Behavioral health coding guide. https://www.ama-assn.org/practice-management/cpt/behavioral-health-coding-guide
American Medical Association. (2026). AMA CPT® 2026 professional edition.
American Medical Billing Association. (2025). Mental health billing [Online course]. https://www.americanmedicalbillingassociation.com/mental-health-billing-course/
Centers for Medicare and Medicaid Services. (2024, May 2). Place of service code set. https://www.cms.gov/medicare/coding-billing/place-of-service-codes/code-sets
Centers for Medicare & Medicaid Services. (2026, January 1). Billing and coding: Psychiatry and psychology services (A57480). Medicare Coverage Database. https://www.cms.gov/medicare-coverage-database/view/article.aspx?articleId=57480
Healthy Connections Medicaid. (2015, March 13). CMS-1500 Completion Guide (Version 02/12). https://medicaidelearning.remote-learner.net/mod/resource/view.php?id=1133
National Uniform Claim Committee. (2025, July). Version 13.0 7/25 1500 Instruction Manual. https://www.nucc.org/images/stories/PDF/1500_claim_form_instruction_manual_2025_07-v13.pdf
Verhovshek, J. (2018, February 5). Modifier GT eliminated for telehealth services. AAPC. https://www.aapc.com/blog/40791-modifier-gt-eliminated-for-telehealth-services/
Williams, J. (2026). Insurance crash course for clinicians [On-demand webinar]. Mental Health Masterminds. https://mhmm.learnworlds.com/course/insurance-10
Educational Disclaimer
The information provided in this blog is intended for educational and informational purposes only and reflects general mental health billing guidelines and industry best practices available at the time of publication. SteadyStream Billing makes every reasonable effort to ensure the accuracy and reliability of the information presented; however, billing requirements, payer policies, regulations, and coding guidelines may change over time.
Readers are responsible for verifying current payer requirements, applicable regulations, and practice-specific guidelines before making billing, coding, or compliance decisions. SteadyStream Billing does not guarantee that the information provided is applicable to every individual practice, payer, or clinical situation.
This content is not intended to replace official payer guidance, legal advice, compliance consultation, or professional billing services. Providers remain responsible for ensuring their own compliance with applicable healthcare regulations and payer requirements.
CPT® is a registered trademark of the American Medical Association.
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