F43.20 diagnosis code at a glance
F43.20 | |
|---|---|
Official description | Adjustment disorder, unspecified |
Billable | Yes, in the FY2027 code set (effective October 1, 2026) |
Parent | F43.2, Adjustment disorders, a header that isn't billable |
Inclusion terms at F43.2 | Culture shock; grief reaction; hospitalism in children |
Excludes2 at F43.2 | Separation anxiety disorder of childhood (F93.0) |
Index entries that end at F43.20 | Disorder, adjustment (grief); Grief, reaction; Nostalgia |
Changed in FY2027 | No |
Adjustment disorder unspecified ICD-10: when F43.20 fits
F43.20 belongs at the start. A referral that reads "adjustment disorder", an intake where the stressor is obvious but you haven't sorted out which symptoms carry the picture, a crisis‑line handoff with one line of history. In each of those, unspecified is accurate.
It stops being accurate fast. By the second or third session most clinicians can say whether the reaction is mainly low mood, mainly worry, both, or behavior. When you can, write it in the assessment and move the code. Leaving F43.20 on every claim for months tells a reviewer that nobody looked again.
F43.20 or one of the subtypes?
What the note describes | Code |
|---|---|
Adjustment disorder, main symptoms not stated | F43.20 |
Low mood leads | F43.21 |
Anxiety leads | F43.22 |
Anxiety and low mood both prominent | F43.23 |
Conduct problems, such as truancy or fighting | F43.24 |
Emotional symptoms and conduct problems together | F43.25 |
Another leading symptom that you specify | F43.29 |
F43.29 is the one people forget. It's for an adjustment disorder you have characterized, just not as mood, anxiety or conduct. If you know the leading symptom and it's none of those, F43.29 says more than F43.20 does.
Subtype pages: F43.21, F43.22 and F43.23. For reactions after a traumatic event, see F43.10 and F43.12.
Adjustment disorder or a life-stage problem?
The ICD‑10‑CM index uses the word "adjustment" for two different things. "Disorder, adjustment" is F43.2‑, a mental disorder. Z60.0, problems of adjustment to life‑cycle transitions, is a circumstance, and the tabular lists empty nest syndrome, phase of life problem and trouble adjusting to retirement under it.
So a client who is unsettled after the last child leaves home, with no clinically significant symptoms, fits Z60.0. If the same client is crying daily and has stopped going to work, that's an adjustment disorder, and Z60.0 can still go second to name the stressor. Z73.3, stress not elsewhere classified, is the general fallback for strain with no disorder; its Excludes1 note sends work‑related stress to the Z56 codes instead.
Two more index entries are worth knowing. "Nostalgia" indexes straight to F43.20, and "Homesickness" sends you to Disorder, adjustment. "Situational reaction" and "situational disturbance" also point to adjustment disorder, but add "acute" and the index gives F43.0, acute stress reaction.
What to document for F43.20
- The stressor, named plainly, and its date.
- When symptoms began relative to that date.
- What you've seen so far, even if it's mixed or unclear.
- Why it isn't better explained by a depressive, anxiety or trauma disorder.
- What you'll assess next to settle the subtype, and when.
Example, fictional client. Client, 47, moved her father into her home in July after his stroke. Since August: irritable with her teenagers, poor sleep, missed two deadlines at work, says she feels "underwater". First visit today; mood and anxiety symptoms both described, neither clearly dominant yet. No prior psychiatric history. Assessment: adjustment disorder, unspecified (F43.20); Z63.6, dependent relative needing care at home. Plan: PHQ‑9 and GAD‑7 next session, decide subtype by session three, caregiver resource list given.
Our treatment plan template has room for the reassessment date, which is what turns F43.20 into a subtype on schedule.
Billing F43.20
CPT code | Use with F43.20 |
|---|---|
90791 | The intake visit, often where F43.20 first appears |
90832, 90837 | Individual psychotherapy, by time |
90846 | Family psychotherapy without the client, for example meeting the spouse about caregiving |
90839 | Psychotherapy for crisis, when the stressor has caused an acute crisis |
More on each: 90791, 90832, 90837, 90846 and 90839.
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Common mistakes with F43.20
- Never updating it. If later notes describe low mood or worry in detail, the code should follow.
- F43.20 for a life transition with no disorder. Z60.0 or Z73.3 is the honest code there.
- Billing F43.2. It's a header. The claim needs five characters.
- Two subtypes on one claim. There's one adjustment disorder. Pick the subtype, or F43.23 for mixed mood and anxiety.
- Missing an acute stress reaction. "Acute situational reaction" in a referral indexes to F43.0, not F43.20.
If an AI scribe drafts the assessment, check that the subtype you settled on is actually in it. Our guide to DAP, BIRP and GIRP progress notes covers what to review before signing.
Checked against the FY2027 ICD‑10‑CM code set from CMS on October 19, 2026. F43.20 and the rest of F43.2 did not change this year.