Medicare Fee-for-Service for Behavioral

Medicare (Original / FFS)

Original Medicare — Fee-for-Service (Parts A and B)

Original Medicare fee-for-service guide for behavioral health providers covering Part A and Part B, MACs, PECOS enrollment, OTP benefit, and claims.

Quick Reference

Payer Type

Government

Parent Company

Centers for Medicare & Medicaid Services (CMS)

Headquarters

Baltimore, MD

Provider Portal

Open Portal

Portal Guide

View Guide →

Credentialing

PECOS enrollment (Provider Enrollment, Chain, and Ownership System) via the Medicare Administrative Contractor (MAC) for your jurisdiction

Timeline

Typically 60-120 days after submission of a complete CMS-855 application

Coverage

1 states

Last Verified

Apr 19, 2026

Published

Apr 19, 2026

Reading Time

12 min

Covered Levels of Care

• Inpatient psychiatric hospital services (Part A)
• Partial Hospitalization Program (Part B)
• Intensive Outpatient Program (Part B)
• Outpatient psychiatric and psychological services (Part B)
• Opioid Treatment Program services (Part B, 42 CFR 410.67)
• Medication-Assisted Treatment (Part B, office-based)
• Skilled nursing and hospice (Part A, when behavioral health criteria met)

Medical Necessity Criteria

• CMS National Coverage Determinations (NCDs)
• Local Coverage Determinations (LCDs) issued by the MAC
• CMS Internet-Only Manuals (Benefit Policy Manual Chapters 6, 9, 15)

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Overview

Original Medicare is the federal health insurance program for adults age 65 and older, certain younger adults with disabilities, and individuals with end-stage renal disease and ALS. It is administered directly by the Centers for Medicare & Medicaid Services (CMS) ↗, an agency of the US Department of Health and Human Services, through regional contractors known as Medicare Administrative Contractors (MACs). This page covers Original Medicare — Part A (hospital insurance) and Part B (medical insurance) — specifically, and does not address Medicare Advantage (Part C), which is a separate Medicare option administered by private plans with their own networks, rules, and contracting processes.

The distinction matters for behavioral health providers because Original Medicare and Medicare Advantage work very differently at the claims and authorization level. Under Original Medicare, claims route to the MAC assigned to your jurisdiction at statutory fee schedules with no prospective authorization for most services. Under Medicare Advantage, each plan has its own payer ID, network rules, prior authorization requirements, and reimbursement terms. A provider enrolled in Medicare through PECOS automatically receives Original Medicare beneficiaries — but must separately contract with Medicare Advantage plans to be in-network for those members.

Behavioral health coverage under Original Medicare has expanded materially over the past several years. The Medicare Part B Opioid Treatment Program benefit launched in January 2020, creating the first Medicare-funded methadone benefit. Marriage and family therapists and mental health counselors became independently enrollable under the Consolidated Appropriations Act of 2023, effective January 1, 2024. Medicare began covering intensive outpatient programs as a distinct Part B benefit in 2024. These changes have made Original Medicare a more meaningful payer for many behavioral health facilities than it was a decade ago.

Behavioral Health Coverage

Medicare Part A covers inpatient hospital services, including inpatient psychiatric care in distinct-part psychiatric units of acute care hospitals and in freestanding Inpatient Psychiatric Facilities (IPFs). IPF services are paid under the IPF Prospective Payment System (IPF PPS), a per-diem methodology with adjustments for patient characteristics and facility factors. Section 1812 of the Social Security Act imposes a 190-day lifetime limit on Medicare coverage of inpatient psychiatric services in freestanding IPFs; stays in distinct-part psychiatric units of general acute care hospitals are not subject to this cap. Part A also covers skilled nursing facility care and hospice services when behavioral health conditions meet the applicable medical necessity standards.

Medicare Part B covers outpatient behavioral health services, including individual and group psychotherapy, psychiatric diagnostic evaluation, psychiatric medication management (evaluation and management codes when delivered by psychiatrists or other prescribing clinicians), psychological and neuropsychological testing, partial hospitalization programs (PHP), intensive outpatient programs (IOP), opioid treatment program services under 42 CFR 410.67, and behavioral health integration and collaborative care services. Part B providers include psychiatrists, psychologists, clinical social workers, physician assistants, nurse practitioners, clinical nurse specialists, and — effective January 1, 2024 — marriage and family therapists and mental health counselors.

The Opioid Treatment Program benefit is a particularly distinctive element of Medicare behavioral health coverage. Under 42 CFR 410.67, Medicare pays SAMHSA-certified OTPs through bundled HCPCS G-codes (G2067 through G2080 and related add-ons) that cover a defined episode — typically a week — of treatment including medication, counseling, and drug testing. OTPs must enroll in Medicare through PECOS using the CMS-855B application. The bundled rates are updated annually through the Physician Fee Schedule final rule published in the Federal Register.

Medical necessity for Medicare behavioral health services is governed by CMS National Coverage Determinations (NCDs), Local Coverage Determinations issued by each MAC, and the Medicare Benefit Policy Manual (CMS Publication 100-02), particularly Chapters 6 (hospital services), 9 (hospice), and 15 (covered medical and other health services). These publications are available at cms.gov/regulations-and-guidance/guidance/manuals ↗.

Credentialing and Provider Enrollment

Medicare provider enrollment is not credentialing in the commercial-payer sense. Instead, providers enroll with Medicare by submitting the applicable CMS-855 application through the PECOS system ↗. PECOS routes the application to the MAC serving your state, which verifies licensure, accreditation, ownership, and other requirements before approving the enrollment and issuing a Medicare billing privilege.

The applicable forms depend on entity type:

Applications must include supporting documentation: state license, professional liability insurance, accreditation where applicable, NPI for the individual and organization, Tax ID and W-9, ownership and managing control disclosure, and program-specific certifications (such as SAMHSA OTP certification for opioid treatment programs). Processing typically runs approximately 60 to 120 days. Denials of enrollment carry appeal rights through the CMS administrative process.

Revalidation occurs every five years for most provider types and every three years for durable medical equipment suppliers, per 42 CFR 424.515 ↗. CMS notifies providers in advance of their revalidation due date; failure to revalidate results in deactivation of billing privileges.

• CMS-855I — Individual clinicians (psychiatrists, psychologists, clinical social workers, licensed mental health counselors, marriage and family therapists, physician assistants, nurse practitioners, clinical nurse specialists).
• CMS-855A — Institutional providers such as hospitals, skilled nursing facilities, hospices, and Inpatient Psychiatric Facilities.
• CMS-855B — Clinics, group practices, and certain other non-physician institutional suppliers including Opioid Treatment Programs.
• CMS-855R — Reassignment of benefits (typically used when a clinician bills through a group practice).
• CMS-855O — Ordering/referring-only enrollment for practitioners who do not bill Medicare directly but order services.

Verification of Benefits (VOB)

Original Medicare eligibility is verified through the CMS HIPAA Eligibility Transaction System (HETS) via 270/271 transactions, typically through your clearinghouse. Verification should confirm Part A and Part B entitlement, the Medicare Beneficiary Identifier (MBI), deductible status and remaining benefit periods, and whether the beneficiary has coverage through a Medicare Advantage plan (Part C), in which case claims must go to that plan rather than the MAC.

Providers should also check for supplemental coverage: Medicare Supplement (Medigap) plans pay after Medicare for cost-sharing; Medicaid as a secondary for dual-eligible beneficiaries; TRICARE For Life for military retirees; and private retirement plans. Medicare is generally primary for beneficiaries who are eligible for Medicare on the basis of age or disability (except in limited end-stage renal disease situations during the coordination period). For dual-eligible beneficiaries, Medicare is primary and Medicaid is secondary — the Medicare claim must adjudicate first and the Medicaid claim includes the Medicare remittance.

Because Original Medicare does not use prospective authorization, VOB focuses on confirming eligibility, determining secondary payers, and checking the beneficiary’s remaining lifetime reserve days or 190-day IPF limit where applicable.

Prior Authorization Requirements

Original Medicare generally does not require prospective prior authorization for behavioral health services. Medical necessity is evaluated after the fact against National Coverage Determinations, Local Coverage Determinations, and the Medicare Benefit Policy Manual. The absence of prospective authorization does not mean there is no coverage risk — medical necessity can be denied at claims adjudication or during post-payment audits by the MAC, the Recovery Audit Contractor program, or the Comprehensive Error Rate Testing program.

CMS has implemented prior authorization demonstrations for specific service categories, but these generally do not apply to behavioral health. Certain durable medical equipment and some hospital outpatient department services are subject to prior authorization under specific demonstration authorities.

For inpatient psychiatric care in IPFs, CMS requires physician certification of the medical necessity and active treatment plan at admission and at defined intervals during the stay, per 42 CFR 412.27 ↗. Partial hospitalization programs require physician certification of active treatment and specific medical necessity documentation per the Medicare Benefit Policy Manual. Failure to meet these documentation requirements can result in post-payment denials even though there was no prospective authorization.

Important: Medicare Advantage plans frequently do require prior authorization for the same services. Providers treating Medicare Advantage enrollees must follow each MA plan’s authorization rules, which may be substantially more restrictive than Original Medicare.

Claims and Billing

Medicare fee-for-service claims route to the Medicare Administrative Contractor ↗ for your jurisdiction. MACs are organized into geographic jurisdictions — for example, CGS Administrators, Novitas Solutions, Palmetto GBA, First Coast Service Options, Noridian Healthcare Solutions, WPS Government Health Administrators, and NGS are among the current MAC contractors. MAC assignments change periodically when CMS rebids contracts; verify your current MAC at the CMS MAC directory linked above.

Institutional claims (inpatient psychiatric, IPF, PHP, OTP when billed as an institutional provider) use the UB-04 or 837I format and route to the Part A MAC. Professional claims (psychiatrist, psychologist, clinical social worker, LMHC, MFT, PA, NP visits) use CMS-1500 or 837P and route to the Part B MAC. Some MACs handle both A and B functions for their jurisdiction.

The Medicare timely filing limit is one calendar year from the date of service per 42 CFR 424.44 ↗. This is significantly longer than most commercial payers but is strictly enforced; claims filed beyond one year are denied with very limited good-cause exceptions.

Common denial reasons include beneficiary enrolled in Medicare Advantage (claim should have gone to the MA plan), services not meeting the LCD criteria, missing physician certification for IPF or PHP, incorrect modifiers or place-of-service codes, and coding errors. The MAC remittance advice uses standardized Claim Adjustment Reason Codes and Remittance Advice Remark Codes that identify the specific denial reason.

Appeals follow the five-level Medicare appeals process established by the Social Security Act: redetermination by the MAC (Level 1), reconsideration by a Qualified Independent Contractor (Level 2), Administrative Law Judge hearing (Level 3), Medicare Appeals Council review (Level 4), and federal district court review (Level 5). Filing deadlines and procedures are specified in the denial notice and in 42 CFR Part 405 ↗. Deadlines are strictly enforced and missed filing cutoffs generally extinguish appeal rights.

Payer Operations Quick Reference

Original Medicare has no national provider phone number, no single payer ID, and no central claims address — everything operational routes through the Medicare Administrative Contractor (MAC) for your jurisdiction. The one datum that is universal: timely filing is one calendar year from the date of service ( 42 CFR 424.44 ↗; Medicare Claims Processing Manual, Pub. 100-04, Ch. 1, §70).

Step 1: Find your MAC

• Look up your jurisdiction at the CMS MAC directory ↗ (source: cms.gov, accessed 2026-06-11). Current MAC contractors include Noridian, Novitas, Palmetto GBA, First Coast, CGS, WPS, and NGS — assignments change when CMS rebids contracts, so verify rather than rely on memory.
• Each MAC runs its own provider contact center — that is “the Medicare provider phone number” for your jurisdiction.
• 1-800-MEDICARE is the beneficiary line, not a provider line — calling it for claims questions wastes the hold time.

Payer IDs and EDI

• Payer IDs are MAC- and line-of-business-specific: institutional claims (UB-04/ 837I ) go to your Part A MAC, professional claims (CMS-1500/837P) to your Part B MAC, each under its own electronic payer ID per your clearinghouse list.
• Eligibility runs through HETS 270/271 — confirm the beneficiary is not enrolled in a Medicare Advantage plan, the single most common misrouting (MA claims go to the private plan, never the MAC).
• ERA/ 835 and EFT enrollment are handled per-MAC through their EDI enrollment processes.

Timely filing limit — the universal datum

Strictly enforced; good-cause exceptions are narrow (e.g., administrative error by Medicare, retroactive entitlement). Cross-payer table: /denial-code-timely-filing.

Claims and appeals

• Electronic only in practice: Medicare requires electronic submission for most providers under ASCA; paper exceptions are narrow.
• Appeals: the five-level process — MAC redetermination (120 days from the remittance to file), QIC reconsideration, ALJ, Appeals Council, federal court — per 42 CFR Part 405 ↗. Deadlines extinguish rights; calendar them at denial.

Enrollment (Medicare’s version of credentialing)

• PECOS ↗ + the CMS-855 series (855I individuals, 855A institutional, 855B clinics/OTPs); ~60–120 days; revalidation every 5 years. See insurance credentialing for how this differs from commercial credentialing.

Prior-auth quirks for behavioral health levels of care

Key references: CMS Medicare ↗ · Internet-Only Manuals ↗ · Medicare Coverage Database ↗ · Physician Fee Schedule / OTP rates ↗ · SAMHSA OTP certification ↗. Operational data last reviewed 2026-06-11; quarterly re-verification cadence applies. See /rcm for how routes claims to the correct MAC and tracks the one-year window.

• No prospective prior authorization for behavioral health under Original Medicare — review is retrospective against NCDs, your MAC’s LCDs, and the Benefit Policy Manual. The risk shifts to post-payment audits (MAC, RAC, CERT).
• The documentation gates that replace auth: physician certification at admission and defined intervals for IPF stays ( 42 CFR 412.27 ↗ ) and certification of active treatment for PHP; IOP became a distinct Part B benefit in 2024.
• The 190-day lifetime limit applies to freestanding IPF stays only — check remaining days during VOB.
• Medicare Advantage is the opposite world: prior auth is common — see the member’s MA plan, not this page.

Frequently Asked Questions

Original Medicare (Parts A and B) is the traditional fee-for-service program administered directly by [CMS](https://www.cms.gov) through regional Medicare Administrative Contractors (MACs). Claims submit to the MAC and pay at statutory fee schedules. Medicare Advantage (Part C) plans are private insurance plans contracted by CMS to administer Medicare benefits — they have their own networks, prior authorization rules, and payer IDs. Providers must enroll in Original Medicare through [PECOS](https://pecos.cms.hhs.gov) regardless of whether they plan to see Medicare Advantage members; then separately contract with each Medicare Advantage plan. This guide covers Original Medicare only.

Medicare enrollment is managed through [PECOS](https://pecos.cms.hhs.gov), the CMS Provider Enrollment, Chain, and Ownership System. Individual clinicians (psychiatrists, psychologists, clinical social workers, licensed mental health counselors, mental health counselors, marriage and family therapists, physician assistants, nurse practitioners) submit CMS-855I. Facility-type providers such as certified opioid treatment programs submit CMS-855A or CMS-855B depending on the entity type. Applications route to the MAC for your jurisdiction. Processing typically runs approximately 60 to 120 days. Note that Medicare added licensed mental health counselors and marriage and family therapists as independently enrollable providers effective January 1, 2024 under the Consolidated Appropriations Act.

Effective January 1, 2020, Medicare Part B covers opioid treatment program services through a bundled payment methodology defined in [42 CFR 410.67](https://www.ecfr.gov/current/title-42/chapter-IV/subchapter-B/part-410/subpart-B/section-410.67). The OTP benefit covers FDA-approved medications for opioid use disorder (methadone, buprenorphine, naltrexone), substance use counseling, individual and group therapy, toxicology testing, intake activities, and periodic assessments. OTPs must be [SAMHSA-certified](https://www.samhsa.gov/medications-substance-use-disorders) and enroll in Medicare through PECOS. The bundled rate is published annually in the Physician Fee Schedule final rule. HCPCS G-codes G2067-G2080 identify the specific OTP bundles.

Original Medicare generally does not require prospective prior authorization for most Part A or Part B services. Instead, coverage is evaluated retrospectively against National Coverage Determinations, Local Coverage Determinations issued by the MAC, and the Medicare Benefit Policy Manual. Inpatient psychiatric stays in a distinct-part psychiatric unit or Inpatient Psychiatric Facility are subject to the 190-day lifetime limit under Section 1812 of the Social Security Act. Partial hospitalization under Part B requires a physician certification of active treatment and medical necessity. Medicare Advantage plans (Part C) often require prior authorization — this differs from Original Medicare.

Claims submit to the [Medicare Administrative Contractor (MAC)](https://www.cms.gov/medicare/coding-billing/medicare-administrative-contractors-macs) for your jurisdiction. There are separate Part A/B MACs organized into jurisdictions covering all 50 states. Institutional claims (UB-04/837I) go to the Part A MAC; professional claims (CMS-1500/837P) go to the Part B MAC. The Medicare timely filing limit is one calendar year from the date of service, per [42 CFR 424.44](https://www.ecfr.gov/current/title-42/chapter-IV/subchapter-B/part-424/subpart-D/section-424.44). Claims filed after that are denied with no appeal rights except in narrowly defined good-cause circumstances.

There is no national Medicare provider phone number — provider inquiries go to the Medicare Administrative Contractor (MAC) for your jurisdiction, and each MAC operates its own provider contact center. Find your MAC and its contact information through the CMS MAC directory at cms.gov/medicare/coding-billing/medicare-administrative-contractors-macs. The 1-800-MEDICARE line is for beneficiaries, not providers.

Medicare fee-for-service payer IDs are MAC-specific — each Medicare Administrative Contractor has its own electronic payer ID for its jurisdiction, and Part A (institutional) and Part B (professional) claims may use different IDs. Look up your jurisdiction's MAC at the CMS MAC directory, then match its payer ID on your clearinghouse payer list. Medicare Advantage plans use entirely different payer IDs.

One calendar year from the date of service, per 42 CFR 424.44 and the Medicare Claims Processing Manual (Pub. 100-04, Chapter 1, Section 70). This is the one operational datum that holds across all MAC jurisdictions. It is strictly enforced — late claims are denied with only narrow good-cause exceptions.

Related Payers

Key Billing Concepts

Revenue Cycle Resources

This guide is provided for informational purposes only and does not constitute legal, regulatory, or professional advice. Payer requirements, phone numbers, and portal URLs are subject to change. Always verify current information directly with the payer. is not affiliated with the insurance companies described on this page.

• Provider Portal
• Billing Hub
• Code Directory
• RCM Software

Reference tables

Common questions

Official sources

• Open Portalcms.gov
• Centers for Medicare & Medicaid Services (CMS)cms.gov
• cms.gov/regulations-and-guidance/guidance/manualscms.gov
• PECOS systempecos.cms.hhs.gov
• 42 CFR 424.515ecfr.gov
• 42 CFR 412.27ecfr.gov
• Medicare Administrative Contractorcms.gov
• 42 CFR 424.44ecfr.gov
• 42 CFR Part 405ecfr.gov
• Medicare Coverage Databasecms.gov
• Physician Fee Schedule / OTP ratescms.gov
• SAMHSA OTP certificationsamhsa.gov