Health Information Management

Prequalify patients for hyperbaric oxygen therapy to ensure accurate reimbursement

JustCoding News: Outpatient, May 19, 2010

Want to receive articles like this one in your inbox? Subscribe to JustCoding News: Outpatient!

Hyperbaric oxygen (HBO) therapy is a relatively new service that uses a special chamber, sometimes called a pressure chamber, to increase the amount of oxygen in the blood.

HBO is an adjunctive therapy, meaning it is not the primary source of therapy that a practitioner would use, says Gloria Miller, CPC, vice president of reimbursement at Comprehensive Healthcare Solutions in Tacoma, WA.

For example, standard wound care in patients with diabetic wounds includes debridement by any means to remove devitalized tissue, maintenance of a clean, moist bed of granulation tissue with appropriate moist dressings, 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. In that situation, the patient may be a candidate for HBO therapy.

Different MACs and FIs interpret the rules for HBO reimbursement differently. Private payers may also have different rules regarding payment for HBO.

So how do you know whether a patient is covered?

It’s important to note the differences between payers, says Gloryanne Bryant, BS, RHIA, RHIT, CCS, CCDS, regional managing director of HIM for Kaiser Permanente in Oakland, CA.

“When we say a patient is Medicare, we need to know what MAC or FI we have in addition to knowing they’re Medicare,” Bryant says.

Start with the NCD

CMS issued a national coverage determination (NCD) for HBO therapy in 2006. Medicare will cover HBO therapy for the following 15 conditions under certain circumstances:

  1. Acute carbon monoxide intoxication
  2. Decompression illness
  3. Gas embolism
  4. Gas gangrene
  5. Acute traumatic peripheral ischemia
  6. Crush injuries and suturing of severed limbs
  7. Progressive necrotizing infections (necrotizing fasciitis)
  8. Acute peripheral arterial insufficiency
  9. Preparation and preservation of compromised skin grafts
  10. Chronic refractory osteomyelitis
  11. Osteoradionecrosis
  12. Soft tissue radionecrosis
  13. Cyanide poisoning
  14. Actinomycosis
  15. Diabetic wounds of the lower extremities

To be a candidate for HBO therapy, the patient must not show measurable signs of healing for at least 30 days of treatment with standard wound therapy. “That’s very important to note because that means you have to document that in the record,” Bryant says.

The 30 days of treatment do not have to be provided in a wound clinic, says Miller. “The patient could have had 30 days of wound therapy in any setting as long as you have documentation of that and that the wound is not healing,” she explains.

Learn your contractor’s rules

In addition to the NCD, your MAC or FI may have a related local coverage determination (LCD) or article. Review these for any documentation requirements. Also, carefully examine the LCD to ensure that the documentation clinicians provide includes the necessary details that are going to get you paid and allow you to keep the money in the event of an audit, Miller says.

You can eliminate some denials by having clinical staff members use a prequalification checklist before they start patients on HBO.

“This is where you want to focus your energy for looking at your LCD or article,” says Miller. Include the common outpatient conditions your facility treats with HBO on the form. Customize the form to include the procedures your particular MAC or FI will cover.

The prequalification statement will assist providers in determining whether HBO therapy is appropriate, and also gives HIM professionals a starting place to determine whether the HBO therapy is covered.

You can also use the prequalification statement to help practitioners remember the necessary documentation for each diagnosis. The physician can then work through that checklist before starting a patient on HBO therapy.

Establish medical necessity

Not all patients or all wounds qualify for HBO therapy, so practitioners should document medical necessity for HBO therapy, and HIM staff must ensure that documentation is included in the record.

Look to your LCD to find the diagnosis codes your MAC or FI has approved for HBO therapy, Miller says. Make sure the diagnosis in the record matches an approved diagnosis in your MAC’s or FI’s LCD. For example, a diabetes patient must have the specific diabetes code included in the LCD.

“They can’t just have a generic or not otherwise specified diagnosis,” Miller says.

Each patient record should include:

  • History and physical
  • Assessment of the patient as a candidate for hyperbarics
  • Evaluation of medical necessity
  • Treatment plan
  • Regular documentation of progress and reassessments of the treatment plan
  • Daily logs of the procedure, including ascent time, descent time, and total
  • Bottom time, dose of oxygen, pressurization level
  • Documentation of attendance and a recording of events

Code properly

Only two codes apply to HBO therapy:

  • HCPCS code C1300 (hyperbaric oxygen under pressure, full body chamber, per 30-minute interval). This code is for the hospital and represents the actual service, Miller says. It is typically billed in 30-minute increments. A dive generally takes 110 minutes, so you would round that up to four units, she explains. If the treatment lasts 90 or fewer minutes, report three units.
  • CPT code 99183 (physician attendance and supervision of hyperbaric oxygen therapy, per session). This code applies for the entire treatment and is not a time-based code. It also includes the pre- and post-treatment documentation.

Only report an evaluation and management code for the initial HBO therapy evaluation if the physician performs a separate service beyond the HBO therapy, Miller says.

Ensure complete documentation

Think about documentation for HBO the same way you think about documentation for other procedures—if it wasn’t documented, it didn’t happen. “It’s important to teach providers and clinical staff that they need to paint a picture of the patient,” Miller says. Clinical staff members need to show medical necessity because medical necessity is the overriding rule of all of the documentation requirements, she adds.

The documentation should also state that the physician supervised and was in attendance during the HBO treatment.

Physician supervision is not broken into increments, so if the physician was in attendance at the beginning of the treatment and again at the end of treatment, you can bill for supervision.

The physician does not need to be in attendance for the entire treatment. However, “they do need to be immediately available in case of a problem,” Miller says.

Editor's note: This article was originally published in the June issue of Briefings on APCs. E-mail your questions to Managing Editor Michelle A. Leppert, CPC-A, at

Want to receive articles like this one in your inbox? Subscribe to JustCoding News: Outpatient!

Most Popular