Medicare for Clinical Social Workers: Who Qualifies, What It Pays, How to Enroll

Clinical social workers were among the first non-physician mental health professionals Medicare paid directly. Section 1861(hh) of the Social Security Act, added by the Omnibus Budget Reconciliation Act of 1989, defines who counts as a clinical social worker (CSW) and what "clinical social worker services" are. The benefit sits in Part B.

The details below come from 42 CFR 410.73, the Medicare Benefit Policy Manual (chapter 15, section 170), the Claims Processing Manual (chapter 12, section 150), and CMS's Medicare & Mental Health Coverage booklet (MLN1986542, March 2026).

Who qualifies as a CSW?

Under 42 CFR 410.73(a), a clinical social worker:

1. has a master's or doctorate in social work;
2. has performed at least two years of supervised clinical social work after the degree; and
3. is licensed or certified as a clinical social worker by the state where the services are performed.

For a state with no clinical social work license, the regulation substitutes the highest social work license the state issues plus at least 2 years or 3,000 hours of post-master's supervised clinical social work. In practice, every state has a clinical license, so read this as: your independent clinical license (LCSW, LICSW, LISW-CP, LCSW-C, or Michigan's LMSW with a clinical designation) in the state where the patient is.

A master's-level license that allows clinical work only under supervision does not qualify. We cover the LMSW question separately in can an LMSW bill insurance?

What does Medicare cover?

CSW services are services "for the diagnosis and treatment of mental illness" that the CSW is legally authorized to perform under state law, of a type that would be covered if a physician furnished them. In practice that means psychiatric diagnostic evaluations and psychotherapy codes, plus some others CMS has opened to CSWs over time, including the health behavior assessment and intervention codes. See health behavior codes for social workers.

The exclusions matter as much as the coverage. Medicare does not pay under the CSW benefit for hospital inpatients, services within partial hospitalization or intensive outpatient programs run by a hospital outpatient department or community mental health center, or certain SNF and dialysis-facility services. That list has its own post: what Medicare will not pay CSWs for.

What does it pay?

• 75% of the clinical psychologist's physician fee schedule amount for the same service (MLN1986542). Because the psychologist rate is itself a fee schedule amount, a CSW's rate moves every year with the fee schedule.
• Assignment is required. You accept Medicare's allowed amount as payment in full and cannot balance-bill.
• If you reassign your billing to a Method II critical access hospital, CMS pays the CAH 80% of the lesser of the actual charge or 75% of the psychologist amount.

CSWs must also follow the consultation rule in 42 CFR 410.73(c): with the patient's consent, you notify or try to notify the patient's attending or primary care physician, unless the patient's physician referred them. Document either the consultation or the attempt.

Can someone bill incident to a CSW?

No. CMS's booklet is explicit that services provided incident to a CSW's own services are not covered. A CSW can provide services incident to a physician, clinical psychologist, nurse practitioner, physician assistant, clinical nurse specialist or certified nurse-midwife, as auxiliary personnel. For behavioral health, CMS allows that under general supervision.

How does enrollment work?

You enroll as an individual practitioner on the CMS-855I, online through PECOS or on paper, and you sign it yourself. If you join a group, the group's reassignment is handled separately. Three points trip up multistate clinicians:

• Enrollment follows the patient's state. If you see Medicare patients located in two states, you need a license in each and an enrollment that covers each. Adding a state license does not add a Medicare enrollment.
• Licenses on file must match. Your enrollment lists the license for the state where you practice. A lapsed license there can stop payment.
• Revalidation comes around. Medicare revalidates enrollments on a cycle; missing it deactivates billing.

Our sister site White Glove Credentialing handles Medicare enrollment, reassignment and revalidation. Its guides on enrolling through PECOS, reassignment of benefits and revalidation walk through each step.

Enroll, or opt out?

CSWs can choose not to bill Medicare at all, either by never enrolling (in which case they generally cannot treat Medicare beneficiaries for covered services and charge them privately) or by opting out through a formal affidavit and private contracts with each patient. Opting out is a multi-year commitment. Talk it through before you file; it is hard to reverse quickly.

How this fits with licensing

Medicare credentialing assumes the licensing is already done. The order we see work best:

1. Get the clinical license in each state where your Medicare patients are.
2. Get an NPI if you do not have one, and keep its address current.
3. Enroll (or add the state) through PECOS.
4. Only then schedule Medicare patients in that state.

We handle step 1: the state license applications and the LMSW-to-LCSW Clinical License Upgrade for clinicians not yet at the independent level. White Glove Credentialing handles step 3. If the compact eventually lets you practice in other member states, Medicare will still need your enrollment to reflect where patients are; we will update this post when CMS says how it will treat multistate licenses.