On January 1, 2024, Medicare Part B quietly expanded to cover mental health services provided by Licensed Clinical Social Workers and Licensed Marriage and Family Therapists — a change that had been decades in the making. For LCSWs who were already Medicare-eligible, little changed. But for LMFTs and LPCs newly entering Medicare billing, the learning curve has been steep, and the compliance risks are real.
This guide explains what changed, what it means for your billing, and where newly-eligible therapists are making the most costly documentation mistakes.
Congress included a provision in the 2023 Consolidated Appropriations Act that extended Medicare Part B coverage to Marriage and Family Therapists and Mental Health Counselors starting January 1, 2024. This followed years of advocacy by professional associations who argued that the exclusion created access barriers for Medicare beneficiaries seeking mental health services.
The practical effect: tens of thousands of LMFTs and LMHCs can now enroll as Medicare providers and bill Part B directly for psychotherapy and related mental health services. Most have never billed Medicare before, and the compliance infrastructure that physician practices take for granted — billing specialists, compliance officers, EHR-embedded audit tools — simply doesn't exist in the typical solo private practice.
Key enrollment fact: You must actively enroll with Medicare to bill — eligibility doesn't happen automatically. Enrollment through PECOS can take 60–90 days. If you're not yet enrolled and see Medicare beneficiaries, you may be providing uncompensated care.
Medicare covers the standard psychotherapy CPT code set for newly eligible therapists: 90832 (30-minute psychotherapy), 90834 (45-minute psychotherapy), and 90837 (60-minute psychotherapy). The psychiatric diagnostic evaluation (90791) is covered for the initial assessment. Family therapy codes 90846 and 90847 are also covered under specific circumstances.
What many newly billing therapists don't realize is that Medicare's documentation requirements for these codes differ meaningfully from commercial payer requirements. Medicare requires explicit documentation of medical necessity in every session note — not just a diagnosis code, but a narrative that connects the patient's clinical presentation to the services provided. Notes that would sail through United or Aetna review can fail Medicare audit standards.
One of the most common compliance questions from newly billing therapists involves telehealth. Medicare's post-PHE telehealth rules for mental health services are complex, and they changed again in late 2024 and 2025 as Congress extended various pandemic-era flexibilities.
The place of service code matters: POS 02 (telehealth provided other than patient's home) and POS 10 (telehealth provided in patient's home) carry different documentation requirements, and getting them wrong creates a billing error even when the underlying service is legitimate. Audio-only sessions have separate coverage rules and are not covered identically to video sessions.
The Office of Inspector General periodically flags high-risk billing populations for increased scrutiny, and newly credentialed providers in any specialty tend to attract attention — not because of fraud, but because documentation errors are more common among providers new to a payer's requirements. Therapists who billed exclusively commercial insurance for years and then entered Medicare billing in 2024 are a textbook new-biller population.
The most common errors the OIG finds in mental health audits: insufficient medical necessity documentation, incorrect time-based billing for psychotherapy codes, and telehealth claims with incorrect place of service codes.
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