Photodynamic Therapy | CMS Coverage Update

Summary: The Centers for Medicare & Medicaid Services modified its photodynamic therapy coverage policy, effective May 15, 2026. Here's what billing teams need to know before that date.

CMS photodynamic therapy coverage policy updates don't come often, but when they do, they hit dermatology, oncology, and gastroenterology practices hard. This modification touches how Medicare evaluates medical necessity for PDT services. The policy does not list specific CPT or HCPCS codes in the available data — we'll address that directly in the codes section below.

CMS Photodynamic Therapy Coverage Criteria and Medical Necessity Requirements 2026

The Centers for Medicare & Medicaid Services has modified its coverage policy for photodynamic therapy (PDT). PDT is a treatment that uses a photosensitizing drug combined with a light source to destroy abnormal cells. Medicare covers it across several clinical settings — but coverage is tightly tied to medical necessity criteria, and this modification signals that CMS is tightening how those criteria apply.

Photodynamic therapy billing under Medicare has always required documentation that shows the clinical need clearly. That means your records need to show the diagnosis, the treatment site, and why PDT was chosen over alternatives. A claim denial for PDT almost always traces back to thin documentation, not a coding error.

The real issue here is that CMS modifications — even when they look minor — often shift what reviewers look for during medical review. If your documentation was built around an older version of this coverage policy, it may not hold up post-May 15, 2026.

Because the full policy detail is not available in this data set, you should pull the complete policy text directly from the CMS source before the effective date. The policy is accessible at app.payerpolicy.org/p/cms/128-v3. Do not assume the criteria stayed the same as the prior version.

Prior authorization is not universally required for PDT under Medicare, but Medicare Administrative Contractor (MAC) policies can add prior auth requirements on top of the national framework. Check with your MAC before billing PDT for any indication you haven't billed recently.

CMS Photodynamic Therapy Exclusions and Non-Covered Indications

Medicare's coverage of photodynamic therapy has historically been limited to specific indications. Outside those indications, PDT is considered experimental or investigational by CMS.

CMS has consistently excluded PDT for off-label oncologic uses that lack sufficient clinical evidence. Treatments that don't meet the medical necessity threshold — either because the diagnosis doesn't align with covered indications or because the patient's condition falls outside the policy's criteria — will result in a claim denial.

Because the specific exclusions in this modified policy are not available in the current data, treat any PDT indication that isn't clearly documented as covered with caution. If you have volume in any of the less common PDT applications — beyond actinic keratosis, esophageal cancer, or endobronchial tumors — loop in your compliance officer before the effective date.

This is not a situation where you want to assume continuity. Modifications to CMS coverage policies regularly expand exclusions or add documentation requirements that weren't in the prior version.

Coverage Indications at a Glance

The following table reflects the historically covered and non-covered indications under CMS photodynamic therapy policy, based on established Medicare coverage positions. Because specific indication-level changes are not available in the current policy data, treat this as a baseline — not a confirmed summary of the modified policy.

Important: Verify each indication against the full modified policy text before May 15, 2026. This table reflects historical CMS positions. The modification may have changed coverage status for one or more indications.

CMS Photodynamic Therapy Billing Guidelines and Action Items 2026

Photodynamic therapy billing under Medicare requires precision. Here are the concrete steps your team should take before the May 15, 2026 effective date.

CPT, HCPCS, and ICD-10 Codes for Photodynamic Therapy Under This CMS Policy

The policy data available for this modification does not include specific CPT, HCPCS, or ICD-10 codes. This is not unusual — CMS policy documents sometimes reference codes in a format that isn't captured in summary data.

Do not use codes from memory or general knowledge for this policy. Pull the complete policy document before May 15, 2026 and build your code list from the actual text.

What to Look For in the Full Policy

When you access the full modified policy, look for:

• CPT codes in the 96570–96571 range — these are the historically used photodynamic therapy codes for dermatologic applications. Confirm whether they're listed and what criteria apply.
• CPT codes for PDT in gastroenterology and pulmonology contexts — these appear in different code ranges and may carry different medical necessity criteria.
• HCPCS drug codes for photosensitizing agents — PDT requires a photosensitizing drug (like aminolevulinic acid or porfimer sodium). The drug code and the procedure code must be billed together. A mismatch between drug and procedure codes is a common claim denial trigger.
• ICD-10-CM codes — make sure your diagnosis codes align with the covered indications in the modified policy. An outdated or overly broad diagnosis code is a fast path to denial.

Because this post cannot responsibly list codes that aren't confirmed in the policy data, this section will be updated when the full code list is available. Check app.payerpolicy.org/p/cms/128-v3 for the complete code set.