Pick 97165 when
Low complexity
- A focused problem, one to three deficits
- No relevant comorbidities
- Every assessment completed without help
Guide · Occupational therapy coding
Occupational therapy billing codes: 97165 to 97168 and the units that follow
Short answer: the evaluation level comes from three components read together, deficits, comorbidities and assistance, never minutes. Units come from total timed minutes in the day; GO on every OT line, CO at 85% where an OTA furnished the minutes.
97165 · low · 1 to 3 deficits
97166 · moderate · 3 to 5
97167 · high · 5 or more
97168 · re-evaluation · change in function
Edition
Oct 2026
Focus
OT coding
Audience
OT owners · coders
Codes
97165 to 97168
Metric
8 to 22 min = 1 unit
Length
7 min read
What separates 97165, 97166, 97167 and 97168
Created for January 1, 2017 to replace 97003 and 97004; all four are always-therapy codes carrying GO [1].
| Code | Occupational profile and history | Performance deficits | Clinical decision making | Typical time |
|---|---|---|---|---|
| 97165 low | Brief history; record review for the presenting problem | 1 to 3 | Limited options; no comorbidities affecting performance; no assistance needed | 30 min |
| 97166 moderate | Expanded review plus physical, cognitive or psychosocial history tied to function | 3 to 5 | Several options; comorbidities may be present; minimal to moderate assistance | 45 min |
| 97167 high | Record review plus extensive additional history | 5 or more | Multiple options; comorbidities present; significant assistance | 60 min |
| 97168 re-evaluation | Update to the initial profile for changes in condition or environment | Change in functional or medical status | Revised plan; documented change in function or significant plan change | 30 min |
A guide to the visit, not a billing criterion
Typical face-to-face minutes in the CPT descriptors
Evaluation codes are untimed: one unit whatever the minutes. The three components decide the level [1].
30 min50% of high97165low complexity
45 min75% of high97166moderate
60 min100%97167high complexity
30 min50% of high97168re-evaluation
Initial evaluation levelsRe-evaluation
97165 against 97166: three questions a reviewer asks at once
Most downcodes happen here: 97166 gets chosen as the safe middle. All three lines must hold.
QuestionSupports 97165Moves the level up
How many deficits?Write them as a numbered list
97165One to three performance deficits
97166 / 97167Three to five supports 97166; five or more supports 97167
Comorbidities?Affecting occupational performance
97165None that affect occupational performance
97166 / 97167If one does, say which; 97165 is off the table
Help to complete?Modification or assistance
97165Not necessary
97166 / 97167Minimal to moderate points to 97166; significant points to 97167
Three sentences decide the level
Pick 97166 when
Moderate complexity
- Three to five deficits, a wider history
- Comorbidities that may affect performance
- Some assistance was needed
Pick 97167 when
High complexity
- Five or more deficits, extensive history
- Comorbidities that do affect performance
- Significant assistance or task modification
Re-evaluation, progress report, recertification: only one is a code
97168 is for an established patient when a revised plan is indicated: a documented change in function or a significant plan change. The routine progress report is part of the visit [4].
| Document | When | Billable? | Source |
|---|---|---|---|
| Progress report | Every 10 treatment days from day one, evaluation included | No code; written by the clinician as part of care | BPM Ch. 15, 220.3 |
| Re-evaluation 97168 | Documented change in function or a significant change to the plan of care | Yes, one unit with GO | CPT descriptor, MM9782 |
| Recertification | Every 90 days, or when the plan is significantly modified | Not a service; physician or NPP signature on the plan | BPM Ch. 15, 220.1.3 |
The unit ladder: total timed minutes, then the table
Most OT treatment bills in 15-minute timed codes: 97530, 97535, 97110, 97112. Claims Processing Manual Chapter 5, 20.2 sets units from total timed minutes in the day [2].
Units billed by total timed minutes in a day
Add every timed minute, then read the units. A lone timed service needs 8 minutes. Untimed codes, evaluations and 97010 included, bill one unit regardless.
1 unit8 through 22 min
8 to 2212% of 127
2 units23 through 37 min
23 to 3712%
3 units38 through 52 min
38 to 52Visit A lands here, 45 min
4 units53 through 67 min
53 to 6712%
5 units68 through 82 min
68 to 8212%
6 units83 through 97 min
83 to 9712%
7 units98 through 112 min
98 to 11212%
8 units113 through 127 min
113 to 12711%
0326495127 min
Minute band for each unit countBand for worked Visit A below
Visit A bills three units, Visit B bills one
Visit A: 45 total timed minutes
Both over 15 minutes, so each gets a unit; the third goes to the longer one.
97530therapeutic activities
25 min56% of time, 2 units
97535self-care training
20 min44%, 1 unit
Total timed38 to 52 band
45 min3 units billed
Visit B: 97166 plus 22 timed minutes
One untimed unit for the evaluation. 22 minutes sit in the 8 to 22 band: one timed unit, to 97110.
97110therapeutic exercise
12 min55% of time, 1 unit
97530therapeutic activities
10 min45%, 0 units
Total timed8 to 22 band
22 min1 unit billed, plus 97166
The trapVisit B: two timed services, one unit between them. A unit of each overbills by one, the pattern CARC 151 denials look for. Check any visit in the therapy units calculator.
GO on every line, CO where the OTA worked, KX above the line
GO
Always-therapy modifier
- Every OT line, 97165 to 97168 included [1]
CO
OTA furnished the minutes
- 85% of the fee schedule since January 1, 2022 [3]
- Line by line, de minimis standard
KX
Above the annual threshold
- OT threshold $2,480 in CY 2026, $2,540 proposed for 2027 [5]
- Independent of CO; both can sit on one line
Both modifiers switching on across one year: the OT KX and CO case study. Thresholds, plan-of-care clocks, RTM and audits: the OT billing guide 2027.
Takeaway
Count the deficits, name the comorbidities, describe the assistance. Those three sentences decide the level; total timed minutes, not the number of codes, decide the units.
A five-minute self-check
Pull ten evaluations from last monthDocumented deficits against the level billed.
Pull ten treatment visitsRe-count units from total timed minutes.
Find every 97168 in the quarterA documented change in function or plan behind each.
Check GO and COGO on every OT line; CO only where an OTA furnished the minutes.
Trace CARC 151 and CARC 4 denialsEach one maps to one of the four checks above.
Check payer-specific evaluation rulesIntervals vary by state and plan: therapy payer matrix. Above the threshold: KX documentation checklist.
Frequently asked questions
What is the difference between 97165 and 97166?
97165, low complexity: one to three deficits, no comorbidities affecting occupational performance, no assistance needed, typically 30 minutes. 97166, moderate: three to five deficits, expanded history, comorbidities that may affect performance, minimal to moderate assistance, typically 45 minutes. All three components are read together.
Is 97168 billable for a progress report?
No. The descriptor reserves 97168 for a documented change in functional status or a significant plan change. The progress report, due every 10 treatment days, is part of the visit and has no code.
How are billing units counted for occupational therapy?
Claims Processing Manual Chapter 5, 20.2: add all timed minutes in the day and read the table: 8 through 22 is one unit, 23 through 37 two, 38 through 52 three, in 15-minute steps. Untimed codes bill one unit regardless.
Does the CO modifier change what Medicare pays?
Yes. Services furnished in whole or part by an OTA carry CO and have been paid at 85 percent of the fee schedule since January 1, 2022. CO is separate from KX, which attests medical necessity above the $2,480 OT threshold in 2026.
- CMS MLN Matters MM9782, 2017 Annual Update to the Therapy Code List: 97161 to 97168 long descriptors and GO modifier
- Medicare Claims Processing Manual, Chapter 5, section 20.2, Reporting of Service Units With HCPCS
- CMS, Therapy Services: CQ/CO modifiers at 85 percent, KX modifier thresholds
- Medicare Benefit Policy Manual, Chapter 15, sections 220.1.3 and 220.3: recertification and progress reports
- Federal Register public inspection, CY 2027 PFS proposed rule: proposed CY 2027 KX threshold of $2,540
Checked October 25, 2026. Rules change; confirm against the source. Items marked proposed come from the CY 2027 PFS proposed rule and are not final until the final rule publishes.
Want ten of your OT evaluations and visits checked?
We read each evaluation against the level billed, re-count units from timed minutes, and show where GO, CO and KX are missing or misplaced.