Medicare vs Commercial Insurance: Behavioral Health Billing Rules Explained

Two patients book the same 60-minute therapy session on the same day. One has Medicare. The other has a commercial plan through work. The care is identical, but the claims are not. Each one follows different rules for who can bill, what needs approval first, how telehealth is coded, and how long you have to file.

This is the daily reality of behavioral health insurance billing. Most mental health practices see a mix of Medicare, Medicare Advantage, and commercial patients. When the billing team treats them all the same way, claims get denied, payments come in low, and old balances quietly pile up.

This guide explains where Medicare and commercial insurance really differ for behavioral health billing in 2026. It covers provider eligibility, prior authorization, telehealth, timely filing, and behavioral health reimbursement. It also shows how a dedicated billing partner keeps both sides of your payer mix paid on time.

How is Medicare different from commercial insurance for behavioral health billing? 

Medicare uses one national set of rules. It pays 80% of the approved amount after the Part B deductible, rarely requires prior authorization for outpatient therapy, and gives you 12 months to file. Since 2024, licensed marriage and family therapists and mental health counselors can bill Medicare directly. Commercial plans set their own rules. Each one decides its rates, authorization needs, session limits, telehealth codes and filing deadlines, often 90 to 180 days. Many also send mental health claims to a separate behavioral health company, so the payer on the card may not be the payer that pays.

Medicare vs Commercial Insurance at a Glance

Before the details, here is the big picture. Medicare is one payer with one rulebook. Commercial insurance has many payers, each with its own rulebook, and the rulebook can change by plan, by employer, and by year.

How Medicare Behavioral Health Billing Works

Medicare behavioral health billing runs under Part B. After the yearly deductible, Medicare pays 80% of the approved fee schedule amount and the patient owes 20%. Claims go to a Medicare Administrative Contractor (MAC), the company that processes Medicare claims for your region. For Florida practices, that is First Coast Service Options.

Who can bill Medicare for mental health

This changed in a big way in 2024. Licensed marriage and family therapists (MFTs) and mental health counselors (MHCs) can now enroll and bill Medicare on their own. Before 2024, many practices simply could not see Medicare patients with these clinicians. Addiction and drug and alcohol counselors who meet the MHC rules can enroll too.

The catch is the rate. MFTs, MHCs and licensed clinical social workers are paid 75% of what Medicare pays a clinical psychologist for the same code. So a 90837 session pays a different amount depending on who provided it. Practices that set their revenue goals on one flat rate across all clinicians often miss their numbers.

Every clinician must be enrolled in Medicare before the first visit they bill. Enrollment goes through PECOS, Medicare's online enrollment system, and the effective date matters. Sessions before that date cannot be billed.

What Medicare looks for

Medicare rarely asks for approval before outpatient therapy. Instead, it checks after the fact. Every session must be medically necessary, linked to a covered diagnosis, and supported by a note. For time-based psychotherapy codes, the note must show the actual session time.

A 90837 billed with a note that shows 50 minutes is one of the most common audit findings in mental health insurance billing. Medicare can take back the difference years later, across every session with the same pattern.

Medicare telehealth for behavioral health

Patients can receive mental health telehealth at home through December 31, 2027, with no rural or location limits. Audio-only visits are allowed in that window. The in-person visit rule, which requires a face-to-face visit before telehealth starts and every 12 months after, has been delayed until January 1, 2028. Patients who start telehealth before then will only need the yearly in-person visit after that date.

Medicare Advantage is not traditional Medicare

Many "Medicare" patients are actually on Medicare Advantage, a private plan that replaces traditional Medicare. These plans behave much more like commercial insurance. They may require prior authorization, use a separate behavioral health network, and set their own filing deadlines. Billing a Medicare Advantage patient as if they had traditional Medicare is a fast route to a denial.

How Commercial Insurance Billing Works for Behavioral Health

Commercial insurance billing is less about one rulebook and more about managing many. Each payer contract sets its own rates, rules and deadlines. A practice with ten commercial payers effectively has ten different billing systems to follow.

Behavioral health carve-outs

Many commercial plans do not manage mental health benefits themselves. They hand them to a separate behavioral health company, often called a carve-out. The patient's card shows one insurer, but the mental health claim must go to another company, with its own payer ID, rules and credentialing. Sending the claim to the name on the card is one of the most common reasons behavioral health claims are rejected.

Prior authorization and visit reviews

Many commercial plans allow a set number of outpatient sessions, then ask for a treatment update or authorization to continue. Higher levels of care, such as intensive outpatient or partial hospitalization, almost always need approval before the first day. When an authorization expires mid-treatment and no one notices, every session after that date is at risk.

Parity and why it matters

Federal mental health parity law says most commercial plans cannot make mental health benefits harder to use than medical benefits. That covers things like copays, visit limits and approval rules. Parity does not set your rate, but it gives your team a strong basis to appeal limits that look stricter than the plan's medical rules.

Rates, credentialing and filing deadlines

Commercial behavioral health reimbursement depends on your contract. Two plans can pay very different amounts for the same 90834. Some plans pay less to master's-level clinicians, and some pay more for certain codes or for telehealth parity.

Each clinician must be credentialed with each plan, and with the carve-out company where one exists. Filing deadlines are usually shorter than Medicare's 12 months, often 90 to 180 days. A claim that sits in a queue for a few weeks can lose its window entirely.

Where Behavioral Health Practices Lose Revenue Across Both

The biggest losses rarely come from one large denial. They come from small gaps that repeat every week:

• The wrong payer. The claim goes to the insurer on the card instead of the carve-out company, or to traditional Medicare instead of a Medicare Advantage plan.

• Clinicians not enrolled or credentialed. A new counselor starts seeing patients before their Medicare enrollment or commercial credentialing is active.

• Expired authorizations. Commercial sessions keep going after the approved visits run out.

• Time codes that do not match notes. A 90837 with a 50-minute note, or a 90834 when the session ran 55 minutes and could have been billed higher.

• Telehealth coding mix-ups. Place of service and modifiers follow Medicare's rules on one claim and a commercial plan's rules on the next. Using one set for both causes denials.

• Missed filing windows. Commercial claims that would have been fine under Medicare's 12 months are lost at 90 days.

• Secondary claims left unbilled. Medicare patients with a supplement, or commercial patients with two plans, leave the second payment on the table. Our guide to coordination of benefits for behavioral health practices explains how payment order works.

Should You Bill Medicare and Commercial Plans In House?

In-house billing works when your biller knows Medicare rules, every commercial contract, and every carve-out, and has time to keep up with all of them. That is a lot for one person who also answers phones and checks eligibility.

Outsourcing makes sense when your denials are rising, claims are aging past 60 days, a new clinician is waiting on credentialing, or your clinicians are doing billing work after hours. A partner that handles behavioral health billing every day already knows which payer wants what, and keeps up with changes for you.

How Avorcms Services Helps With Behavioral Health Insurance Billing

Avorcms Services provides behavioral health billing services for therapy, counseling and psychiatry practices. We manage both sides of your payer mix, so Medicare and commercial claims each follow the right rules from the start.

Here is what we take off your plate:

• Eligibility and benefit checks before the first session, including whether the patient has traditional Medicare or Medicare Advantage, and which company actually pays mental health claims.

• Medicare and commercial payer credentialing, including Medicare enrollment for MFTs and mental health counselors, so new clinicians can bill from day one.

• Authorization tracking with alerts before approved visits run out.

• Coding review that matches each psychotherapy code to the time in the note, and applies the right telehealth codes for each payer.

• Behavioral health claim denial management that finds the cause, fixes it, and appeals, including parity-based appeals where they apply.

• Full revenue cycle management for mental health practices, with clear reports and a dedicated account manager.

We are based in St. Petersburg and provide behavioral health billing services in Florida, along with support for practices across the United States.

See What Your Payer Mix Is Really Paying

If your Medicare and commercial claims are being denied, delayed, or paid less than you expect, the cause is usually a handful of repeat errors. Our team will review your recent claims across both payer types and show you exactly where revenue is slipping.

Start with a free medical billing audit, call (727) 662 8558, or email [email protected]. We respond within 24 hours.

Frequently Asked Questions

1. What is the main difference between Medicare and commercial insurance for behavioral health billing? Medicare follows one national set of rules from CMS. Commercial insurance follows the rules of each plan, so rates, prior authorization, session limits and filing deadlines change from payer to payer.

2. Can licensed mental health counselors bill Medicare? Yes. Since January 1, 2024, licensed mental health counselors and marriage and family therapists can enroll in Medicare and bill for their services directly. Some addiction counselors qualify too.

3. How much does Medicare pay counselors and therapists? MFTs, mental health counselors and clinical social workers are paid 75% of the Medicare rate for a clinical psychologist for the same service.

4. Does Medicare require prior authorization for therapy? Traditional Medicare rarely requires prior authorization for outpatient psychotherapy. Medicare Advantage plans often do, so always check which type of Medicare the patient has.

5. What is the timely filing limit for Medicare vs commercial insurance? Medicare allows 12 months from the date of service. Commercial plans set their own limits in each contract, often 90 to 180 days.

6. Can Medicare patients get mental health care by telehealth at home in 2026? Yes. Medicare covers mental health telehealth at home through December 31, 2027, and audio-only visits are allowed in that time. The in-person visit rule is delayed until January 1, 2028.

7. What is a behavioral health carve-out? A carve-out is when a commercial plan hands its mental health benefits to a separate company. Claims, credentialing and authorizations then go to that company, not the insurer on the patient's card.

8. Why do commercial plans pay different rates for the same therapy code? Commercial behavioral health reimbursement is set by each contract. Rates depend on the plan, the clinician's license level, the code, and sometimes whether the visit was in person or by telehealth.

9. What is mental health parity? Parity is a federal rule that says most plans cannot make mental health benefits harder to use than medical benefits. It covers limits like copays, visit caps and approval rules, and can support appeals.

10. Does Avorcms Services offer behavioral health billing services in Florida? Yes. Avorcms Services is based in St. Petersburg and handles Medicare, Medicare Advantage and commercial billing for behavioral health practices in Florida and across the United States. Call (727) 662 8558 or email [email protected].

Disclaimer: This blog is for informational and educational purposes only and does not constitute legal, compliance, or financial advice. Medicare and payer rules change often. Always confirm current requirements with CMS, your Medicare Administrative Contractor, and each commercial payer.