back to blog roll

Getting reimbursed for your services - preventing hyperbaric oxygen therapy (HBO) services Medicare denials when treating Diabetic Foot Ulcers (DFU)

When denying HBO services, Medicare generally issues statements explaining reasons for denial. Insufficient documentation is among the most frequent ones. Below is a statement from Wisconsin Physician Services (Medicare Administrative Contractor, or MAC) in response to records that were submitted by a provider’s office for a patient with a Wagner Grade 3 DFU.

"A review of 30 units of HBO therapy services billed on the claim for dates of service _____ through ______ was performed. The HBO therapy services initially denied, as the documentation was insufficient to support the services were medically reasonable and necessary. The 30 units of HBO therapy services will remain denied.

This decision was made in accordance with the Centers for Medicare & Medicaid Services (CMS) Internet Only Manual (IOM), Publication 100-3, Medicare National Coverage Determination (NCD) Manual, Chapter 1, Part 1, Section 20.29. This regulation outlines the covered and non-covered conditions for which Medicare will allow payment for HBO therapy services

The records indicated that HBO treatment began on __________, however the documentation did not include previous wound care records with measurements and records of medical/surgical management to support that the wound demonstrated no signs of healing with conventional treatment for at least 30 days prior to the start of HBO therapy."

Importance of HBO for DFU treatment

Hyperbaric oxygen therapy (HBO) for diabetic foot ulcers (DFU) has been shown to improve healing rates and decrease the number of major amputations in the diabetic population. Recent research and evidence have driven the new paradigm of aggressive treatment and the attempt to save a limb, if at all possible, to prevent the morbidity and mortality associated with a major amputation. HBO is an accepted and approved treatment for DFUs by the Center for Medicare Studies (CMS) and by third-party insurance payers. Patients require careful screening and selection, and the recommendations set forth by CMS and the Undersea and Hyperbaric Medicine Society should be followed. The use of HBO therapy is covered as adjunctive therapy only after there are no measurable signs of healing for at least 30 days of treatment with standard wound therapy. Also, HBO must be used in addition to standard wound care. We have developed an easy to use tool for providers to reference prior to initiating HBOT for the DFU (see link in 'Closing' below). Find out what criteria and documentation should be in place to support medical necessity and ensure insurance coverage. 

Guide for HBO use for DFUs

The Center’s for Medicare and Medicaid Services National Coverage Determination 20.29 states the criteria that must be present and clearly documented in order to meet the medical necessity requirements to initiate hyperbaric oxygen therapy for the Diabetic wounds of the lower extremities. The Criteria are as follows:

  1. Patient has type I or type II diabetes and has a lower extremity wound that is due to diabetes;
  2. Patient has a wound classified as Wagner grade III or higher; and
  3. Patient has failed an adequate course of standard wound therapy.

The use of HBO therapy is covered as adjunctive therapy only after there are no measurable signs of healing for at least 30 –days of treatment with standard wound therapy and must be used in addition to standard wound care.

Standard wound care in patients with diabetic wounds includes:

  1. Assessment of a patient’s vascular status and correction of any vascular problems in the affected limb if possible,
  2. Optimization of nutritional status,
  3. Optimization of glucose control,
  4. Debridement by any means to remove devitalized tissue, maintenance of a clean, moist bed of granulation tissue with appropriate moist dressings,
  5. Appropriate off-loading, and necessary treatment to resolve any infection that might be present.


Failure to respond to standard wound care occurs when there are no measurable signs of healing for at least 30 consecutive days.

Wounds must be evaluated at least every 30 days during administration of HBO therapy.

Continued treatment with HBO therapy is not covered if measurable signs of healing have not been demonstrated within any 30-day period of treatment. [1]

There is further clarification to this in the Novitas Medicare Administrative Contractor (MAC) Local Coverage Determination (LCD) L35021 (now retired) and First Coast Service Options (MAC)  LCD 36504 (now retired):

Wound volume or surface area is expected to measurably diminish over 30 days of wound care.

“Measurable signs of healing” are best defined as specific, documented, clinical evidence of healing. Physician statements should be descriptive and complete with interval measurements to substantiate wound improvement.

Documentation of all aspects of optimization defined by the NCD (clarified by these LCDS) and the absence of improvement in the wound characteristics constitutes stalled wound healing and suggests that it may benefit from adjunctive HBOT.

So, when does the 30 day clock start and how do you document it?

THE CLOCK starts with the patient consultation in your wound center. This allows the provider to ensure Standard of Care has been initiated, maintained and measured to ensure HBOT is medically necessary for treatment of the DFU.  Some might say the clock could start with the referring provider if Standard of Care was provided there. The responsibility falls in the lap of the wound department to ensure that you have obtained all of the documentation supporting standard of care and can produce it for a Medicare audit.

DOCUMENT at least weekly that you continue to address the standards care, making changes if measurable signs of healing are not present, and include wound measurements & assessment. 

During the initial evaluation, the wound provider should immediately institute and document the standard of care steps listed above and state the date of initiation in the History and physical (H&P).

Document any interventions:

  • Antibiotic therapy
  • Laboratory and Pathology findings
  • Radiology studies/ findings
  • Vascular studies/ findings
  • Operative and procedure reports such as debridement


At the end of 30 days, the provider should dictate a separate HBO H&P that clearly states the indication being recommended (DFU) and “tell the story”. Provide the payer with clear and organized documentation.



Effective approach to meet medical necessity guidelines is critical

With the current state of CMS audits through the Targeted Probe and Educate initiative, it is imperative that Wound and HBO centers develop an organized and effective approach for documentation in order to meet medical necessity guidelines.  We have developed an easy to use tool for providers to reference prior to initiating HBOT for the DFU, the "HBO request requirements checklist", part of the Diabetic Foot Ulcer - Hyperbaric Oxygen Therapy Treatment Protocol Guideline (see Plans). This tool includes the CMS criteria for the DFU and should be accessible to all providers. 


To read more on DFU and HBO, see "Diabetic Foot Ulcer - Hyperbaric Oxygen Therapy" on the WoundReference Hyperbaric Oxygen Therapy Knowledge Base. 

The WoundReference Hyperbaric Oxygen Therapy Knowledge Base features guidelines and other important tools to promote high standards of patient care and operational safety within the hyperbaric program. The WoundReference Curbside Consult gives you actionable, specific answers from our expert panel in a timely manner. 

For customized safety programs and other wound care and hyperbaric medicine consultation services, visit MidWest Hyperbaric


We thank Julie Rhee ScM, for style editing


  1. Mize J, Hamm T. "Diabetic Foot Ulcer - Hyperbaric Oxygen Therapy" In: WoundReference. Retrieved May 2018
  2. CMS National Coverage Determination 20.29 
  3. Novitas Local Coverage Determinations 

About the Authors

With over four decades of healthcare experience, Jeff currently holds the position of Principal Partner at Midwest Hyperbaric LLC and the Co-founder and Chief Clinical Officer of Wound Reference. Jeff has excelled in critical care throughout his career, devoting almost a decade as a Flight Respiratory Therapist/Paramedic for the Spirit of Kansas City Life Flight. In 1993, Jeff transitioned into the field of Hyperbaric Medicine and Wound Care, where he committed 21 years of his career to serving as the Program Director for a 24/7 Level 1 UHMS Accredited facility with Distinction. In this role, he continued to provide patient care while overseeing all administrative, clinical, and daily operations within the Wound Care and Hyperbaric Facility. Jeff is a Registered Respiratory Therapist and a Certified Hyperbaric Technologist (CHT). He has also undergone training as a UHMS Safety Director and a UHMS Facility Accreditation Surveyor. Jeff currently serves as a member of the UHMS Accreditation Council, the UHMS Accreditation Forum Expert Panel, and the UHMS Safety Committee. Additionally, he is an esteemed member of the NFPA 99 Hyperbaric and Hypobaric Facilities Technical Standards Committee. Jeff's dedication to the field has earned him numerous prestigious awards. In 2010, he received the Gurnee Award, which honored his outstanding contributions to undersea and hyperbaric medicine. Three years later, in 2013, he was awarded the Paul C. Baker Award for his commitment to Hyperbaric Oxygen Safety Excellence. Most recently, in 2020, Jeff was honored with "The Associates Distinguished Service Award (UHMSADS)," a recognition reserved for exceptional Associate members of the Society who have demonstrated exceptional professionalism and contributions deserving of the highest accolades.
An Advanced Certified Hyperbaric Registered Nurse and Certified Wound Specialist with expertise in billing, coding and reimbursement specific to hyperbaric medicine and wound care services. UHMS Accreditation Surveyor and Safety Director. Principal partner of Midwest Hyperbaric LLC, a hyperbaric and wound consultative service. Tiffany received her primary and advanced hyperbaric training through National Baromedical Services in Columbia South Carolina. In 2021, Tiffany received the UHMS Associate Distinguished Service Award. "This award is presented to individual Associate member of the Society whose professional activities and standing are deemed to be exceptional and deserving of the highest recognition we can bestow upon them . . . who have demonstrated devotion and significant time and effort to the administrative, clinical, mechanical, physiological, safety, technical practice, and/or advancement of the hyperbaric community while achieving the highest level of expertise in their respective field. . . demonstrating the professionalism and ethical standards embodied in this recognition and in the UHMS mission.”
Explore our Wound Care and Hyperbaric Solutions