Occupational therapy evaluation codes: 97165, 97166, 97167, and 97168.
OT evaluation codes are billed on complexity, not the clock, and complexity is decided by three specific documentation components — not a general sense of how involved the visit felt. Get those three components right and the code the note supports is unambiguous; leave one thin and the claim is either under-coded against real clinical work or over-coded against what the record can defend. This guide breaks down exactly what each complexity tier requires, when a genuine re-evaluation (97168) applies versus a routine progress check, the single-unit billing rule that has nothing to do with visit length, and the specific under- and over-coding patterns that cost practices money in both directions.
Key takeaways
- Three documentation components decide the tier — client profile and history, the objective performance-deficit assessment, and clinical decision-making complexity — and all three have to independently support the code billed, not just one of them.
- 97168 requires a genuinely significant clinical change, not a scheduled periodic progress note — billing it as a calendar event rather than a clinical trigger is a recurring medical-necessity denial.
- All four codes bill one unit per encounter, period — there's no timed-unit math here at all, unlike the 97110/97530 treatment family.
- Under-coding is as costly as over-coding here, and far more common — a 97167-level evaluation billed as 97166 because the note undersold its own complexity leaves real, defensible revenue on the table.
The three components that set the tier
Every OT evaluation code — 97165, 97166, and 97167 — is defined by the same three components, and the tier is set by the highest level of documentation the note can actually defend across all three together, not by an average or by whichever component looks strongest.
| Component | Low (97165) | Moderate (97166) | High (97167) |
|---|---|---|---|
| Client profile and history | Brief history focused on the presenting condition; occupational profile addresses only the areas directly relevant to that condition | Expanded review covering the presenting condition plus co-existing factors that could affect occupational performance | Comprehensive review, including psychosocial history, that identifies factors affecting multiple performance areas |
| Occupational performance assessment | 1–3 performance deficits identified, using a standardized instrument or assessment(s) with a clinical presentation that is stable and predictable | 3–5 performance deficits identified; the clinical presentation is evolving, not fully stable | 5 or more performance deficits identified; the clinical presentation is unstable and unpredictable |
| Clinical decision-making | Low complexity — an analysis of the occupational profile and data leads to a plan requiring minimal clinical judgment among treatment options | Moderate complexity — analysis requires an expanded array of data and a moderate number of treatment options | High complexity — analysis requires a highly complex array of data and consideration of a wide range of treatment options |
| Typical time | ~30 minutes | ~45 minutes | ~60 minutes |
Time is listed because it's a genuinely useful sanity check — a note claiming high clinical-decision-making complexity in a visit documented at 22 minutes total is worth a second look — but it is not itself a billing determinant. See the FAQ below and the single-unit section further down: none of these four codes are timed codes, and a longer visit doesn't move the tier on its own.
Documentation checklist by tier
What the note needs to explicitly contain, not just imply, for each tier to hold up on review:
- 97165Low complexity. Occupational profile scoped to the presenting condition; 1–3 named performance deficits with the assessment method used to identify each; a stated plan of care with low-complexity clinical reasoning — for example, an isolated wrist fracture (
S62.001A) with grip strength and fine-motor deficits limiting ADLs, no complicating comorbidities documented. - 97166Moderate complexity. An expanded history noting co-existing factors; 3–5 named performance deficits, each independently assessed; documentation that the clinical presentation is still evolving (symptoms or function not yet stable); reasoning that shows the therapist weighed a moderate range of treatment approaches before setting the plan — for example, a relapsing-remitting multiple sclerosis diagnosis (
G35.A) with fluctuating fatigue, coordination, and ADL performance deficits. - 97167High complexity. Comprehensive history including psychosocial factors; 5 or more named performance deficits spanning multiple domains; explicit documentation that the presentation is unstable or unpredictable; reasoning that shows a wide range of treatment options was considered against a complex data set — for example, a diffuse traumatic brain injury (
S06.2X0A) with cognitive, motor, and safety-awareness deficits across self-care, home management, and community re-entry domains.
Notice what's common to all three checklist entries: a named count of performance deficits, tied to a stated assessment method, is the load-bearing element. A note that says "multiple areas of occupational performance are impacted" without naming and counting them supports none of the three tiers on its own terms, regardless of how much narrative surrounds it.
97168: re-evaluation versus a routine progress note
97168 is where OT evaluation billing goes wrong most often, in both directions. It requires a documented, significant change in the patient's functional status, a new diagnosis, or a clinical finding that materially alters the plan of care — not simply that enough time has passed since the last evaluation.
- A new diagnosis or medical event has changed the clinical picture (e.g., a new stroke in a patient already receiving OT for an unrelated orthopedic condition).
- Functional status has shifted significantly enough — for better or worse — that the existing plan of care no longer fits, and the chart documents specifically what changed.
- A formal re-assessment against the original evaluation's performance deficits produces a materially different count or severity, justifying a revised plan.
- It's simply time for the periodic progress report Medicare requires at defined treatment-day intervals — that report is a documentation requirement, not a separately billable service, and doesn't by itself justify a re-evaluation code.
- The patient is progressing as expected along the original plan of care with no unexpected change.
- The only stated reason is that "it had been a while" since the last formal evaluation.
A payer reviewing a 97168 claim is checking specifically for the clinical trigger — the new diagnosis, the significant status change, the finding that altered the plan. Its absence in the note is grounds for a straightforward medical-necessity denial, and it's one of the more defensible denials a payer can issue, because the code's own definition requires exactly what's missing.
The single-unit billing rule
All four codes — 97165, 97166, 97167, and 97168 — are untimed, per-encounter codes. Each bills exactly one unit per evaluation or re-evaluation encounter, regardless of how many minutes the visit actually took.
| Code family | Unit rule |
|---|---|
97165–97168 (evaluation/re-evaluation) | 1 unit per encounter, always — time does not change the unit count |
97110, 97112, 97530, 97535, 97140 (timed treatment) | Units set by the 8-minute rule — total timed minutes divided per the CMS unit table |
A 45-minute 97166 evaluation and a 70-minute 97166 evaluation both bill as one unit of 97166 — the extra 25 minutes in the second case doesn't generate a second unit, and it doesn't upgrade the code to 97167 unless the deficit count and decision-making complexity documented in the note independently support that tier. This is a genuinely different billing model from the timed treatment codes, and mixing the two up — trying to apply 8-minute-rule logic to an evaluation, or billing multiple units of 97165 for a long visit — is a code-validity error a scrubber should catch before submission. For the full mechanics of unit billing on the timed side, see our 8-minute rule and unit billing guide.
Common under- and over-coding patterns
- 1Under-coding: billing 97165 by default. Some practices default to the lowest evaluation code as a habit or to avoid audit scrutiny, even when the documented deficit count and decision-making complexity clearly support 97166 or 97167. This is the single most common revenue-leaving pattern in evaluation billing, and it's invisible on a denial report because an under-coded claim doesn't deny — it just pays less than the work performed.
- 2Over-coding: billing 97167 without the fifth deficit named. A note that describes complex clinical circumstances in narrative but only formally names four performance deficits doesn't meet 97167's own threshold, regardless of how complicated the case genuinely was. Count the named deficits against the tier billed before the claim goes out.
- 397168 billed as a calendar event. Covered above — the recurring pattern where 97168 gets billed simply because a periodic progress report was due, with no documented clinical trigger.
- 4Time used as a proxy for complexity. A 60-minute visit billed as 97167 purely because it ran long, without the deficit count or decision-making documentation to match, inverts the actual rule — time is a byproduct of complexity, not evidence of it on its own.
Build an evaluation-note template that forces the therapist to explicitly count and name performance deficits as a discrete field, separate from the narrative history and plan sections. Practices that make this one structural change consistently see both fewer over-coded 97167 claims and less silent under-coding at 97165, because the deficit count becomes something a coder or scrubber can check against the code billed, rather than something buried in prose.
Not sure your evaluation coding matches your documentation?
We'll audit a sample of your recent OT evaluation claims against the three tier components, flag under- and over-coded patterns, and show what's recoverable.
Frequently asked questions
Does a longer evaluation automatically justify a higher complexity code?
No. Time is a typical marker of each tier, not the billing determinant — 97165 through 97167 are selected by the number of performance deficits identified and the complexity of the clinical decision-making documented, not by the clock. A 50-minute evaluation that only identifies two performance deficits and low-complexity decision-making still bills as 97165, and a payer or auditor comparing the note to the code will flag the mismatch regardless of how long the visit actually ran.
Can we bill 97168 just because it's time for the patient's periodic progress note?
No. Medicare requires a progress report at defined intervals, but that report is not separately billable and doesn't by itself justify 97168. Re-evaluation requires a documented, significant change in the patient's functional status, a new diagnosis, or a clinical finding that alters the plan of care. Billing 97168 for a routine periodic check-in with no such change documented is a medical-necessity denial waiting to happen, and it's one of the most common over-coding patterns in OT evaluation billing.
Do we bill more than one unit if the evaluation runs long?
No. Each of 97165, 97166, 97167, and 97168 is a single untimed code, billed once per encounter regardless of whether the visit took 25 minutes or 70. The published typical times (roughly 30, 45, and 60 minutes for the three complexity tiers) describe what's typical for that tier's clinical content, not a threshold that unlocks additional units. The 8-minute rule that governs 97110, 97530, and the rest of the timed treatment codes does not apply to the evaluation family at all.
Verify before billing. CPT is a registered trademark of the American Medical Association; codes here are paraphrased, not reproduced from the CPT Professional edition. CPT, HCPCS and ICD-10 codes, coverage policy, and bundling edits change, including annual code-set updates. This page reflects standard industry practice and is provided for general education — it is not a substitute for your own compliance review, your current payer contracts, or the current-year code sets. Confirm requirements against your specific payer mix before submitting claims.