Medicare Part B Opt-Out vs Private Contracting in 2025-2026

The $2,500 Mistake You Make Before Breakfast

You decide you're done with the CMS headache. The low reimbursement rates, the MIPS reporting, and the endless documentation for a simple E/M code aren't worth it anymore. You stop sending claims to Medicare and start charging your senior patients a flat cash fee. Three months later, a letter arrives from your Medicare Administrative Contractor (MAC). You’re being audited, and you’re facing thousands of dollars in fines for illegal billing.

Why? Because you didn't officially opt out. In the eyes of CMS, if you haven't filed the right paperwork, you’re still a "Medicare-eligible" provider bound by their limiting charges.

Choosing between Medicare Part B Opt-Out vs Private Contracting isn't just a business decision; it’s a compliance minefield for 2025-2026. If you want to charge Medicare beneficiaries directly, you have to follow a very specific regulatory script.

The Difference Between "Non-Par" and "Opt-Out"

We see practice managers get this wrong every single week. They think being a "non-participating" provider is the same as being opted out. It isn't.

Non-Participating (Non-Par): You still have a relationship with Medicare. You can choose to accept assignment on a case-by-case basis. You’re still subject to the Medicare Limiting Charge (usually 115% of the Physician Fee Schedule amount). You still have to file claims for the patient.

Opt-Out: You sever the financial tie. You don't bill Medicare. Medicare pays nothing. The patient pays you 100% of your fee out of pocket. To do this legally, you need two things: an affidavit filed with your MAC and a signed private contract with every single Medicare patient you see.

The 2025-2026 Medicare Affidavit: Getting the Paperwork Right

To start the process, you don't just stop calling. You have to tell the government you’re leaving. This requires an affidavit. While some MACs like Noridian or Palmetto GBA have their own specific forms, the requirements are uniform.

Your affidavit must state that you will not submit any claim to Medicare for any item or service provided to a Medicare beneficiary for the next two years. In 2025, CMS is increasingly picky about the "Effective Date." If you file your affidavit mid-quarter, it usually won't take effect until the first day of the following quarter.

If you are currently enrolled via a CMS-855I, you don't necessarily have to "deactivate" your enrollment first, but the MAC will update your status in PECOS to "Opt-Out."

Pro Tip: We see these fail most often when providers forget to list every NPI they are associated with. If you work at two different clinics, your opt-out applies to you as a person, not just the practice. You can't be "in" at the hospital and "out" at your private boutique practice.

Private Contracting: The Legal Shield for Your Cash Fees

Once the MAC processes your affidavit, you aren't in the clear yet. You cannot legally take a dime from a Medicare beneficiary unless they sign a Private Contract.

This isn't a standard "Terms of Service" form. For 2025-2026 compliance, the contract must include specific language:

1. The patient acknowledges they (or their legal representative) accept full responsibility for payment.
2. The patient understands that Medicare's limiting charges do not apply.
3. The patient agrees not to submit a claim to Medicare, even for a "cross-over" to supplemental insurance.
4. The provider acknowledges they are not currently excluded from Medicare under Section 1128.

You must give the patient a copy of this before services are rendered. If you provide an emergency service, you cannot enter into a private contract for that specific episode. Medicare expects you to treat first and worry about the billing later in true emergencies.

Timeline and Deadlines: The Two-Year Cycle

Opting out isn't a permanent divorce; it’s a two-year renewable lease.

• Auto-Renewal: Since 2015, opt-outs automatically renew every two years. If you want to get back into the Medicare system, you have to notify your MAC at least 30 days before your current two-year cycle ends.
• The 90-Day Window: If you change your mind immediately after opting out, you have a 90-day "grace period" to cancel the opt-out. But there’s a catch: you must refund any private pay money you collected that exceeded the Medicare allowed amount during those 90 days.

Why PECOS Still Matters Even If You’re Out

Even if you’ve opted out, you still exist in the PECOS (Provider Enrollment, Chain, and Ownership System) universe. If you want to order lab tests, refer patients to specialists, or prescribe imaging that Medicare will pay for, you must be in the system as an "Ordering and Certifying" provider.

This is where the CMS-855O comes in. If you aren't enrolled for billing (855I) but want to make sure your patients' pharmacy claims aren't denied, you need to maintain that 855O status. We’ve seen specialists lose their entire referral base because they opted out and forgot that their NPI now triggers a "provider not enrolled" rejection at the local pharmacy or imaging center.

Common Pitfalls and Denial Reasons

• Incomplete Affidavits: Missing the Social Security Number or the NPI. MACs will reject these without a second thought.
• Wrong Effective Dates: Trying to backdate an opt-out. CMS doesn't do retro-active opt-outs.
• Supplemental Insurance Confusion: Patients often try to submit your bill to their Medigap or secondary insurer. The secondary insurer will see no Medicare EOB (Explanation of Benefits) and deny the claim. This usually leads to a confused senior calling Medicare, which triggers a flag on your NPI.

Compliance Checklist for 2025-2026

• Verify your current enrollment status in PECOS.
• Identify your MAC (e.g., NGS, Novitas, CGS).
• Draft a Private Contract that meets all 10+ regulatory requirements under CMS IOM Pub. 100-02, Chapter 15.
• File the affidavit at least 30 days before your intended start date.
• Update your CAQH ProView profile to reflect your new status.
• Train front-desk staff: they must never accidentally submit a "placeholder" claim to Medicare for an opted-out provider.

The Next Step

Before you pull the trigger, run a report on your patient demographics. If 60% of your volume is Medicare, opting out is a bold move that requires a massive marketing shift. If you're ready, start by downloading the specific affidavit template from your MAC’s portal today. Don't wing it with a typed letter; use their format to ensure it passes the first time.