Medicare Now Pays for Build-Up Vials: The Update Every Allergy Practice Has Been Waiting For

For years, allergists and practice managers have asked the same question:

When will Medicare finally reimburse for build-up vials?

The build-up phase of allergen immunotherapy is the backbone of long-term desensitization, yet practices have absorbed costs or battled denials for far too long. Now, for the first time, Medicare has moved forward with a significant policy shift, build-up vials are officially reimbursable.

If you haven’t read up on this yet, you’re not late, you’re right on time. This blog will bring you fully up to speed and show you why this update matters more than you think.

Why This Change Matters So Much

This isn’t just a billing update. It’s a milestone for allergy practices, especially those serving a large Medicare population.

1. Practices Can Finally Stop Absorbing Costs

Before this change:

• Many clinics paid out-of-pocket for build-up vials
• Revenue losses were common
• Practices hesitated to initiate immunotherapy for Medicare patients

Now, Medicare reimbursement eliminates the financial burden and brings long-overdue stability.

2. More Medicare Patients Can Start Immunotherapy

Allergen immunotherapy is not just symptom relief; it’s a disease-modifying treatment.

Coverage means:

• Fewer patients delaying care
• Increased access in underserved areas
• Higher adherence rates
• Better long-term outcomes

This is transformative for seniors with severe allergies, asthma, or chronic rhinitis.

3. Administrative Workflows Become Much Cleaner

Billing teams can finally breathe.

With consistent reimbursement:

• Fewer claim denials
• Clearer coding guidelines
• Reduced back-and-forth with MACs
• Simpler revenue cycle processes

In other words, fewer headaches and smoother cash flow.

Understanding Build-Up Vials: Why They Matter Clinically

To understand the significance of this update, we need to understand the role of build-up vials.

The build-up phase is where the work really happens. This is the 3–6 month period when patients gradually escalate their allergen exposure through carefully dosed injections. The vials used in this phase:

• Are prepared specifically for each patient
• Require multiple vials at increasing concentrations
• Represent the foundation of a safe, effective allergy shot program

Without this phase, patients can’t progress to maintenance, the stage that provides long-term relief.

So when Medicare denied or inconsistently reimbursed these vials, it wasn’t just a billing issue.

It was a barrier to care.

What Changed in 2025: The Medicare Reimbursement Shift

Medicare has now authorized reimbursement for build-up vials under recognized CPT/HCPCS codes, aligning with:

• Commercial payer standards
• Longstanding allergist advocacy
• Evidence supporting immunotherapy effectiveness

This move signals a strong message:
Immunotherapy matters and Medicare is ready to support it.

What Your Clinic Should Do Immediately

To get ahead of the curve, practices should take these steps now.

Conclusion

Medicare’s decision to reimburse build-up vials is more than an update; it’s a turning point for allergy care. Practices that act now will see stronger revenue, smoother workflows, and more patients benefiting from life-changing immunotherapy. The door is officially open. Now it’s time to step through it.