Speech therapy billing has a reputation for being straightforward: a handful of evaluation codes, one treatment code, bill it and move on. That reputation is why so many speech therapy practices lose revenue they never notice. The codes are simple. The benefits, the diagnosis rules, the visit limits, and the coordination between commercial plans, Medi-Cal, and regional centers are not.
This guide covers the codes and modifiers speech-language pathologists use most, the benefit rules that drive denials, and the operational habits that keep a pediatric or adult speech practice paid. It also covers the biggest coding change the specialty has seen in years: CPT 92507 is deleted on January 1, 2027.
Evaluation codes
Speech and language evaluations are split by what's being evaluated. Pick the code that matches the full scope of the evaluation, not just the primary concern.
| Code | What it covers |
|---|---|
| 92521 | Evaluation of speech fluency (stuttering, cluttering) |
| 92522 | Evaluation of speech sound production (articulation, phonological process, apraxia, dysarthria) |
| 92523 | Evaluation of speech sound production with evaluation of language comprehension and expression |
| 92524 | Behavioral and qualitative analysis of voice and resonance |
| 92610 | Evaluation of oral and pharyngeal swallowing function |
| 92607 / +92608 | Evaluation for speech-generating AAC device, first hour / each additional 30 minutes |
| 96105 | Assessment of aphasia, per hour |
A common mistake: billing 92522 and 92523 together. 92523 already includes speech sound production, so the pair is redundant and will usually be denied or bundled. If both speech sound and language were evaluated, bill 92523 alone.
Treatment codes
| Code | What it covers |
|---|---|
| 92507 | Individual treatment of speech, language, voice, communication, and/or auditory processing. Untimed, once per day. Deleted January 1, 2027. |
| 92654–92663 | The 2027 replacement codes: timed base and add-on codes for fluency, speech sound, language, combined speech sound and language, and voice/resonance. See the full breakdown. |
| 92508 | Group treatment, two or more individuals |
| 92526 | Treatment of swallowing dysfunction and/or oral function for feeding |
| 92609 | Therapeutic services for use of a speech-generating device |
Diagnosis codes and why they cause denials
The diagnosis on a speech therapy claim does more work than in most specialties, because many health plans treat developmental speech and language disorders differently from conditions caused by an illness or injury. Commonly used codes include F80.0 (phonological disorder), F80.1 (expressive language disorder), F80.2 (mixed receptive-expressive language disorder), F80.81 (childhood-onset fluency disorder), and R48.2 (apraxia), along with medical diagnoses such as autism (F84.0) or hearing loss when they're the underlying cause.
Some plans cover developmental diagnoses only under a "habilitative" benefit, cover them only up to a certain age, or exclude them entirely. Others require the medical condition to be listed first. Before the first visit, verification has to answer a specific question: does this plan cover speech therapy for this diagnosis, for a patient this age, and under which benefit? A generic "therapy is covered" from the benefits line isn't enough.
Modifiers and place of service
- GN indicates services delivered under an outpatient speech-language pathology plan of care. Medicare requires it on therapy codes, and many commercial and Medicaid plans do too.
- KX is used on Medicare claims once a patient's therapy spending passes the annual threshold, attesting that continued therapy is medically necessary and documented.
- 59 / XU may be needed when two services that normally bundle are both legitimately provided as distinct services. Use sparingly and only when documentation supports it.
- Telehealth: payers use different combinations of place of service (02 or 10) and modifiers (95, GT). There isn't a universal rule. Confirm each payer's policy and set it up per payer in your EHR.
- Home visits: place of service 12 (home) is common in pediatric and early intervention work. Some plans pay home visits differently or require prior authorization for them.
Visit limits and authorizations
Most commercial plans cap therapy visits per year, often as a combined limit shared by physical, occupational, and speech therapy. A child who also sees an OT can exhaust the speech benefit months earlier than expected, and the first sign is usually a denial for a session that's already been delivered.
The practices that avoid this track visits used against each patient's limit, including visits at other providers when the plan will disclose them, and flag patients approaching the cap so families can be told in advance. Where plans require prior authorization, the same tracking applies to authorized visits and end dates. Medi-Cal and Medi-Cal managed care plans may require a Treatment Authorization Request or plan-level authorization depending on the service and setting.
Visit-limit denials are the most preventable denial in speech therapy. The information exists at intake. It just has to be recorded, counted, and checked before every authorization period, not discovered on the EOB.
The denials we see most often
| Denial | Usual cause | Prevention |
|---|---|---|
| Benefit maximum reached | Combined PT/OT/ST visit cap exhausted | Count visits per plan year; check at each authorization |
| Non-covered diagnosis | Developmental diagnosis excluded or age-limited | Verify coverage for the specific diagnosis before the evaluation |
| No authorization | Auth expired, wrong code, or wrong provider | Track end dates and visits remaining; renew 2–3 weeks early |
| Missing or invalid modifier | GN omitted, telehealth modifier wrong for the payer | Payer-specific claim rules in the EHR |
| Bundling (92522 with 92523) | Redundant evaluation codes | Bill 92523 alone when both were evaluated |
| Plan of care not signed | Physician certification missing where required | Track certification and recertification dates |
Speech therapy for regional center consumers
In California, many pediatric speech patients are also regional center consumers. The regional center authorizes speech therapy through a Purchase of Service authorization and is generally the payer of last resort, so insurance or Medi-Cal is billed first and the regional center may cover what those sources don't. Getting that order right, and keeping the denials and EOBs that prove it, is most of the work. Our regional center billing guide walks through it step by step.
When to outsource speech therapy billing
A solo SLP with mostly private-pay clients doesn't need a billing company. A practice with several therapists, a mix of commercial, Medi-Cal, and regional center patients, and home and telehealth visits usually does, because the work isn't submitting claims. It's verification, visit counting, authorization tracking, and denial follow-up, every week.
Sharp Networks Group provides speech therapy and home care billing inside the EHR you already use, including PracticeQ, SimplePractice, Tebra, and CentralReach. If you'd like us to look at your denials and aging, schedule a consultation.