Foolproof Guide to Mental Health Billing Codes

Billing is intimidating for many therapists due to the complexity of coding. CPT, ICD-10, DSM-5. . . not only are there multiple sets of codes, but there are also detailed rules around which codes should be used for what services. Mental health billing codes can be overwhelming. 

At the same time, having a firm grip on billing is one of the best things you can do for the health of your practice. Billing accurately, in a timely manner, ensures you get paid what should be for the services you’re providing and creates reliable cash flow for your business. Understanding mental health billing codes will help you optimize your billing so you can focus on what matters most: providing quality care to your clients. 

While billing codes can be complex, there’s no reason you can’t master them. Once you see how the codes work, it will be much easier to determine what codes to use when. Eventually, coding will become second nature. In this guide, we’ll cover what you need to know about CPT, ICD-10, and DSM-5, as well as common coding mistakes therapists make when billing. We’ll also share how to find out what you can expect for reimbursement rates so you have a better idea of what your revenue will be. 

Mental Health Billing Codes 101

Let’s start by looking at the three primary types of mental health codes: CPT, ICD-10, and DSM-5. You’ll want to know what the differences are between each and what they’re used for. 

CPT Codes — The Current Procedural Terminology (CPT) code set is published and maintained by the American Medical Association (AMA). These codes describe tests, evaluations, treatments, and any other medical procedure performed by a healthcare provider for a patient. CPT codes are used in the claims submission process to tell payers what procedures you need reimbursement for.

ICD-10 Codes  — The World Health Organization (WHO) publishes and updates the IDC-10 code set. The U.S. then developed a clinical modification (ICD-10-CM) for medical diagnoses based on the WHO’s ICD-10 set. These codes describe diseases, signs and symptoms, abnormal findings, complaints, and external causes of injury or diseases. An ICD-10 code essentially tells payers why you provided a patient with the services you did.

DSM-5 Codes — All therapists are familiar with the Diagnostic and Statistical Manual of Mental Disorders (DSM), which is the handbook used by health care professionals as the authoritative guide to the diagnosis of mental disorders. The current version is DSM-5. But what makes the DSM-5 confusing is that it also contains diagnoses codes. Next, we’ll explain why you shouldn’t use these codes for billing.

DSM-5 vs. ICD-10: Diagnostic Codes for Mental Health

The DSM-5 is a vital tool to assist therapists in identifying, diagnosing, and describing mental disorders. It also serves to provide clinicians with a common language for communication and research. It helps therapists to determine the best possible path for treatment. 

The fifth edition of the DSM tries to mitigate the confusion with ICD-10 codes by referencing the ICD codes, but because the DSM-5 and ICD-10 aren't strictly related, there are sometimes disconnects between criteria in diagnoses in the two sets of codes. 

The ICD-10 should serve as your diagnostic bible for billing. All payers use and require ICD-10 codes in claims. You’ll need to use the appropriate diagnosis code along with your assessment, clinical impression, and plan of care in your documentation. Because the DSM-5 does reference ICD-10 codes, this version of the DSM makes it easier to find the correct ICD-10 code for a patient. However, you’ll always want to double-check the ICD-10 to be sure.

ICD-10 Codes for Mental Health

ICD-10 codes follow a common convention, making it easier to determine which code is the most accurate one for a particular case. Knowing how the codes are composed will help you navigate them more easily.

All ICD-10 codes start with a single letter, followed by three or more numbers. The G codes all refer to diseases of the nervous system. The Z codes cover situations where the client doesn’t have a specific disorder, such as Z91.4 (personal history of psychological trauma) and Z04.6 (encounter for general psychiatric examination, requested by authority). 

The majority of the mental health ICD-10 codes are F codes, which are divided into the following categories.

  • F00–F09 — organic, including symptomatic, mental disorders
  • F10–F19 — mental and behavioral disorders due to psychoactive substance abuse
  • F20–F29 — schizophrenia, schizotypal, and delusional disorders
  • F30–F39 — mood disorders, depression, and bipolar disorders
  • F40–F49 — neurotic, anxiety, stress-related, and somatoform disorders
  • F50–F59 — behavioral syndromes associated with physiological disturbances and physical factors
  • F60–F69 — disorders of adult personality and behaviors
  • F70–F79 — intellectual disabilities
  • F80–F89 — pervasive and specific developmental disorders
  • F90–F98 — behavioral and emotional disorders with onset usually occurring in childhood and adolescence
  • F99 — unspecified mental disorder

CPT Codes for Mental Health

The procedural codes for mental health (codes 90785-90899) are found in the Psychiatry section of the CPT code set. Some of these codes cover services that must be provided by medical professionals, such as psychiatrists, and others cover services that can be delivered by clinical psychologists, licensed professional counselors, licensed marriage and family therapists, and licensed clinical social workers. 

Common Mental Health CPT Codes

Having a thorough understanding of the most common mental health CPT codes will help ensure that you’re using the best code for the services you provide. Here are the most common codes that you’ll encounter as a therapist.

  • 90837 – Psychotherapy, 60 minutes
  • 90834 – Psychotherapy, 45 minutes
  • 90791 – Psychiatric diagnostic evaluation without medical services
  • 90847 – Family psychotherapy (with client present), 50 minutes
  • 90853 – Group psychotherapy (other than of a multiple-family group)
  • 90846 – Family psychotherapy (without the client present), 50 minutes
  • 90875 – Under other psychiatric services or procedures
  • 90832 – Psychotherapy, 30 minutes
  • 90838 – Psychotherapy, 60 minutes, with E/M service
  • 99404 – Preventive medicine counseling and/or risk factor reduction intervention(s) provided to an individual (separate procedure)

CPT Code Modifiers

Code modifiers are used to convey additional information to a payer, such as the level of provider or when services were provided. There are many different modifiers, but only a few that are commonly used. You’ll want to become familiar with the following modifiers.

  • Modifier 25 — Typically, a single code will accurately describe a session. But occasionally, you may find that a fully separate E/M service is needed (performed by the same provider) on the same day. In this case, modifier 25 calls out that service as separate and reimbursable. Note that you can only attach modifier 25 to codes 99201-99215, 99341-99350.
  • Modifier 59 — This modifier is similar to modifier 25, but it’s used to describe a distinct non-E/M procedural service done on the same day. Note that your documentation must support a separate session. 
  • Modifier GT — Used for telehealth sessions involving interactive audio and video.
  • Modifier UT — Used when the provider sees a patient in crisis.

How to Determine Mental Health Insurance Reimbursement Rates

One of the most common questions therapists have when it comes to billing is how much they can expect to be reimbursed for each CPT coded service. This is a tricky question to answer for several reasons. Let’s explore the factors affecting reimbursement rates and how to determine what you’ll be paid. 

Reimbursement Rates are Always Changing

For one thing, rates are always being updated and changing. Even if you could find a publicly-available list, it could be outdated by the time you discovered it. It wouldn’t be helpful to rely on a published list because of this.

Reimbursement Rates Vary Based on Several Factors

But the main reason it’s difficult to uncover reimbursement rates is that insurance companies don’t publish their rates. This isn’t because they’re trying to be secretive, however. Rates are based on a variety of factors, including the therapist’s office location, the provider’s license, education level, and specialization area. So the reimbursements you receive may be different from a therapist with a similar education level and specialization area who is located in another city. Your reimbursement rate is unique to you. When you’re accepted into a payer’s network, you’ll negotiate your reimbursement rates. And you can renegotiate them every year. 

The exception is Medicare and Medicaid. The Centers for Medicare and Medicaid Services offers a search tool that you can use to see what your reimbursement rate would be on average. 

If you haven’t yet applied to payer networks, you can contact them to learn average reimbursement rates. While the reimbursement rate is only one consideration for deciding which networks to become a part of, it’s an important criterion.

Common Mental Health Coding Mistakes

Avoiding coding mistakes should be a priority for several reasons. First, you want to be sure that you’re being accurately reimbursed for all the services that you’re providing, not leaving money on the table. 

Second, mistakes could cause your practice to be flagged for fraud or abuse. Your practice may be audited, and you could face fines as a result of errors. Here are the common coding mistakes you’ll want to avoid.

Using the wrong CPT code — Because procedure codes are so specific, it can be difficult to choose the right one, particularly if you’re relying on the short description only. Become familiar with the mental health CPT codes, and be sure you have a thorough understanding of the most common codes.

Using outdated codes — The CPT code set and the ICD-10 are continually being updated. While there’s always a grace period after a change, most payers will expect up-to-date codes past a certain date. Be sure you’re not using an old code that you found online.

Unbundling codes — Unbundling codes refers to using multiple CPT codes for a treatment when a single code is available that accurately reflects what was performed. Unbundling is often used in order to increase payment. It’s considered abuse, so you’ll want to be especially careful.

Upcoding — Upcoding is another red flag that can trigger an investigation of abuse or fraud. Upcoding describes the practice of using a code with a higher reimbursement rate when you shouldn’t. For example, if you spend 30 minutes doing a psychotherapy session but use code 90837 (Psychotherapy, 60 minutes), you’re upcoding. You don’t have to have a dishonest intent to get into trouble with upcoding — it could simply be a result of failing to track time.

Using modifiers incorrectly — Modifiers are the two-digit codes that are appended to a CPT code to describe additional information for the payer. Be especially careful when using modifiers 25 and 59.

Forgetting a diagnosis code — It’s easy to forget to include all relevant ICD-10 codes in a claim. But payers look to ICD-10 codes to justify services. If you are providing services that address two different conditions, you’ll need to include both codes in the claim.

Documentation errors — Documentation also proves to payers that your services were necessary. Your documentation should include the reason for the session, the date, relevant history, applicable test results, assessment, clinical impression, diagnosis, and plan of care. Progress notes will also need to be included, which describe the client’s response to treatment and any revision of the diagnosis. Documentation must be robust in order not to trigger a rejection. 

For Further Exploration

This guide should provide a solid starting point for your education in mental health billing codes. While you always have the option of using a billing service, there’s no reason you can’t manage your own claims if you need to. Here are a few additional resources you may want to explore. 

Let MyClientsPlus take insurance billing off your plate. Learn about Managed Billing.