Do you bill for “unspecified” and “other specified” diagnoses?  Well, you aren’t alone.  These diagnoses are those favorite “catch all” diagnoses that many of us lean on heavily.  Some of us, too heavily.  

And why not? Our clients are complex, and rarely fit neatly into those tidy little DSM diagnostic boxes. Yet we’re forced to slap a diagnosis code on that first claim to get paid, so we often use these vague diagnoses as placeholders until we get more information in later sessions.  Or we may use them because we don’t want to put a more specific, pathologizing label on clients.

And clinicians have a wide range of unspecified diagnoses available to them. In the DSM-5-TR, the psychiatric section (F01 to F99) alone contains over 30 unspecified or “other specified” codes covering mood, anxiety, eating, sleeping, substance use, personality, and psychotic disorders.

How Popular Are Unspecified Codes?

Although it’s no secret that these codes are popular, their frequency of use is striking. 

Data from Definitive Healthcare ranks Unspecified Anxiety Disorder (F41.9) as the second most billed code – accounting for 11% of claims, right behind Generalized Anxiety Disorder (F41.1) – with Unspecified Depression coming in seventh.  Similarly, SimplePractice reports that Unspecified Anxiety, Unspecified Adjustment Disorder (F43.20), and Unspecified PTSD (F43.10) all rank within the top seven, while Major Depressive Disorder, Single Episode, Unspecified (F32.9) and ADHD, Unspecified (F90.9) appear in the top 20.

So, what’s the problem?  

While we may think of these as harmless diagnoses, there are significant risks that can accompany their use:

• Higher denial rate:  According to the Healthcare Financial Management Association (HFMA), claims submitted with unspecified codes average 28% higher denial rates compared to claims with explicit specifiers (e.g., mild, moderate, or recurrent)
• Increased audit frequency:  Some insurance audit programs (including Medicare’s Targeted Probe and Educate program) flag clinicians who are outliers —such as those who use the same unspecified diagnosis codes for more than 80% of their caseload  
• Higher audit failure rate: While claims coded with unspecified diagnoses are frequently processed without a problem, when scrutinized in a retrospective audit, these cases have been known to experience a significantly higher audit failure rate.  Clinicians who use this diagnosis throughout treatment may struggle to clearly defend in each progress note the medical necessity for the treatment of a vague diagnosis, especially for long-term therapy  
• Greater risk when using intensive or specialized techniques:  A high number of audit failures come from a mismatch of using intense and specialized techniques (like EMDR or ERP) while maintaining a generic unspecified diagnosis where clinical details (like severity of symptoms) aren’t named in the code
• The danger of F99 – Mental Disorder, not otherwise specified:  Most health plans reject this code because it lacks any clinical specificity   

5 tips when using unspecified diagnoses

So to be clear: it isn’t necessary to completely avoid these codes. However, here are five guidelines to keep in mind when using them:

1. When possible, use only during the assessment phase.  Insurance plans may track how long you use unspecified codes.  While they tend to be fine if you use them for early sessions, continuing to use  an unspecified code may trigger a records request to verify medical necessity.  When using, document missing information (ex. “Due to the limited information available during this initial intake, an unspecified anxiety disorder is assigned while ruling out OCD or GAD”)
2. Within the first several sessions, try to shift to a more specific diagnosis, and document what information led to the change.  Health plans love data, so it’s a great idea to use a screening tool such as the PHQ-9 or GAD-7, and document the score
3. When updating a diagnosis, update the treatment plan.  Make sure your new goals, interventions, and timelines align with your new diagnosis
4. After the assessment phase, opt for an “other specified” code over an unspecified diagnosis when possible if a more specific diagnosis can’t be found. While an unspecified code implies missing clinical details, “other specified” indicates that you have sufficient information but are managing a complex or atypical case. Only use this option when the client’s presentation doesn’t meet standard criteria or involves contradictory findings preventing a more specific diagnosis
5. With non-specific diagnoses, your documentation must be extra detailed to justify medical necessity.  In each session note document symptoms, duration, frequency, intensity, triggers, impairment, other diagnoses considered, criteria that were or were not met, your rationale for your diagnosis, and when you will re-evaluate  

The takeaway

Unspecified and “other specified” diagnoses may serve as convenient placeholders early in treatment, or may seem like a way to shield clients from more harmful diagnoses.  But relying on them too heavily can bring significant risks, including higher rates of claim denials, record requests, and insurance audit failures, which can lead to income loss.

Clinicians should reserve these codes for assessment sessions, or for rare cases where a client’s symptoms truly do not match any more specific disorder. With these codes, excellent documentation is especially important due to the increased health plan scrutiny.  Always document the clinical rationale for using these codes, update them as new information emerges, and ensure treatment plans stay aligned with any changes in diagnosis.

Hate writing session notes, or do you avoid them?  Get help writing brief notes that will please the pickiest insurance plans (including Medicare) —  Check out my training “What’s Missing From Your Charts: Writing Great Notes” which includes my Progress Note Template and shows 8 note samples, or get my Note Template here.    Because writing notes shouldn’t be so hard…