Individual Therapy Billing: CPT 90837, 90834, and 90832 Explained

Short answer: CPT 90837 is individual psychotherapy lasting 53 minutes or more, 90834 covers 38 to 52 minutes, and 90832 covers 16 to 37 minutes. The code is decided by actual session time, not by the appointment slot on the calendar, and 90837 draws more payer scrutiny than the other two because it reimburses the most and audits the documented minutes most closely.

Some of what follows comes from the codes themselves. The rest comes from somewhere Oasys is lucky to sit: Oasys runs at the infrastructure layer of working practices, and we talk constantly with therapists and practice owners about exactly this kind of billing mechanic, the ones that look simple until a claim gets denied or a payer opens a documentation request.

The three codes

CPT 90837, Individual psychotherapy, 60 minutes

53 minutes or more, face-to-face with the patient (or via telehealth where permitted). This is the highest-reimbursing common individual therapy code, which is exactly why it gets audited more than 90834 or 90832. A payer that sees a practice billing 90837 for every single session, every client, every week, is looking at a pattern that invites a documentation request.

CPT 90834, Individual psychotherapy, 45 minutes

38 to 52 minutes. The most commonly billed individual therapy code industry-wide, and the one most clinicians' natural session length actually falls into.

CPT 90832, Individual psychotherapy, 30 minutes

16 to 37 minutes. Used less often in outpatient therapy, more common for brief check-ins, medication-adjacent visits, or specific payer requirements.

All three are claim types Oasys generates directly from the signed note, so which one applies follows the same documented session length a payer would check against.

What decides the code: minutes, not the calendar slot

A session scheduled for 60 minutes that actually runs 48 minutes of clinical content bills as 90834, not 90837. The code follows the documented time, and the documentation has to say what that time actually was, not just repeat the code's own name back as the note.

The note needs an actual start and end time, or a total minutes figure, that a payer can check against the code billed. "60-minute individual session" typed at the top of every note regardless of what happened in the room is exactly the pattern payers flag, because it makes the same claim every time rather than a variable one.

Other platforms may be built differently, and leave the CPT code as a field billing staff set by hand after the fact. Oasys captures session time as part of the note itself, so the minutes behind a code are the minutes a clinician actually documented, not a separate number entered downstream.

Why 90837 gets audited more than the others

Three things converge on 90837 specifically: it pays more per session than 90834 or 90832, a practice that bills it near-universally has an unusually flat distribution across an inherently variable thing (real session length), and CMS and commercial payers have both published guidance flagging exactly this pattern as an audit trigger. None of that means 90837 is wrong to bill. It means the documentation has to earn it every time, not by default.

Other platforms may be built differently, but Oasys ties the CPT code on the claim to the same note the clinician actually signed, rather than a separate billing-side field a staff member sets independently. If the note does not support 53 minutes, the mismatch is visible before the claim goes out, not after a payer flags it.

Add-on and adjacent codes worth knowing

90833 and 90836 are the psychotherapy add-on codes used alongside an evaluation and management (E/M) visit, typically in psychiatric or medication-management settings where a prescriber also does therapy in the same visit. They follow the same time bands as 90832 and 90834 respectively, but are billed in addition to the E/M code, not instead of it. Most outpatient therapy practices without prescribing clinicians will not use these; group practices with psychiatric providers should confirm with each payer which combinations are reimbursed.

Common billing mistakes with individual codes

Billing 90837 by default regardless of actual session length. The code should follow the clock, not a practice-wide habit.

Documentation that states a code's name instead of the session's actual content and duration. "90837, individual psychotherapy" is not documentation. What happened in 53-plus minutes is.

Not adjusting the code when a session runs short. A client who leaves at 40 minutes changes the code to 90834, not a shorter version of 90837.

Confusing time-based codes with add-on codes. 90833 and 90836 are billed with an E/M visit, not as standalone individual therapy codes.

These mistakes share a root cause: the CPT code living apart from the documentation that should justify it. Oasys keeps the two in one record specifically so a mismatch is something a clinician can catch before signing, not something a payer catches months later.

What to ask before you commit to a platform

Does the system pull the CPT code from the same session record the clinician documents, or does billing staff set it separately from what the note says?

Can a clinician see, at the point of signing a note, whether the documented time supports the code being billed?

Does the platform distinguish 90832, 90834, and 90837 automatically, or does someone have to remember the time bands and select manually every session?

If a payer opens a documentation request, can the practice pull the note and the claim together, or are they in two disconnected systems?

Oasys answers the first and last of those by design: the claim is generated from the signed note, so pulling one pulls the other.

How Oasys handles it

Oasys generates the CPT-coded claim directly from the signed note rather than from a separate billing-side entry, so the code billed and the documentation behind it are the same record, not two versions that can quietly drift apart. Pricing is $80 per clinician per month on an annual contract, with no per-claim fee and no add-on tier for insurance billing.

FAQ

What is the difference between CPT 90834 and 90837? Time. 90834 covers 38 to 52 minutes of individual psychotherapy; 90837 covers 53 minutes or more. The clinical content can be similar; the code follows the documented duration.

Why does 90837 get audited more than 90834? It reimburses more per session, and a practice that bills it for nearly every session regardless of actual length produces an unusually uniform pattern for something that should vary. CMS and commercial payers have both flagged this specific pattern in audit guidance.

Can I bill 90837 for a 50-minute session? No. 90837 requires 53 minutes or more of documented time. A 50-minute session bills as 90834.

What is CPT 90832 used for? Individual psychotherapy lasting 16 to 37 minutes, typically a brief check-in or a shorter session than standard outpatient therapy, and it is billed less often than 90834 or 90837 in general outpatient practice.

Do I need to document the exact session length for every code? Yes. The safest practice is documenting an actual start and end time or a total minutes figure for every session, regardless of which code is billed, so the note itself supports the code if a payer ever asks.

What does insurance billing cost on a platform like Oasys? Oasys prices at $80 per clinician per month on an annual contract, with billing included and no per-claim fee, so correcting a miscoded session does not carry a separate transaction cost.

The code is not a description of the appointment type. It is a claim about what actually happened in the room, and the documentation is the only thing that can back that claim up later.