Select the Appropriate Inhalation Treatment Code

Once you know when to apply 94640, 94644, and +94645, you can breathe a sigh of coding relief.

By G. John Verhovshek, MA, CPC
Recently, Coding Edge was asked, “What is the proper application of and distinction between inhalation treatment codes 94640 and 94644, +94645?”
CPT® added 94644 Continuous inhalation treatment with aerosol medication for acute airway obstruction; first hour and add-on code 94645 Continuous inhalation treatment with aerosol medication for acute airway obstruction; each additional hour (list separately in addition to code for primary procedure) in 2007 to describe continuous inhalation treatment with aerosol medication for the treatment of acute bronchospasm in patients with severe asthma and/or impending respiratory failure.
According to CPT Changes 2007: An Insider’s View, 94644/+94645 differ from 94640 Pressurized or nonpressurized inhalation treatment for acute airways obstruction or for sputum induction for diagnostic purposes (eg, with an aerosol generator, nebulizer, metered dose inhaler or intermittent positive pressure breathing (IPPB) device) in that:

  • The treatment described by 94640 is administered several times a day at short intervals (e.g., 10 minutes), whereas continuous inhalation treatment is administered for longer periods and then discontinued;
  • A higher dosage of medication is administered in continuous inhalation treatment; and
  • Different equipment is used in administering continuous inhalation treatment.

Codes 94644 and 94645 are time based, and medical chart notes should indicate clearly treatment start/stop times, as well as total duration. Report 94644 for the first hour of treatment, and one unit of 94645 for each additional hour. Add-on code 94645 never should be reported alone, but always with 94644 as the principle service. If continuous inhalation treatment is administered for less than one hour, report 94640 instead of 94644, American Medical Association (AMA) instructions specify.
Inhalation Therapy Quick Coding Chart
Total service time Code selection
Less than 60 minutes               94640
60-90 minutes                          94644
91-150 minutes                        94644, 94645
151-210 minutes                      94644, 94645 x 2
And so on. Note that CPT® guidelines allow reporting more than one inhalation treatment per day by appending modifier 76 Repeat procedure or service by same physician to the second and subsequent units of 94640.
For Medicare payers (and many private payers), don’t report 94640 in addition to 94644-94645 if, for example, the patient required continuous nebulizer treatment and later in the same visit received a 10-minute aerosol breathing treatment. The national Correct Coding Initiative (CCI) bundles 94644 and code 94640 as column 1/column 2 codes, with 94644 as the more extensive procedure. The code pair edit receives a “0” modifier indicator, meaning that the codes may not be billed together under any circumstances.
CPT Assistant, April 2007 (“Ventilatory Management,” pages 3-6) provides a clinical example of continuous inhalation treatment. In brief:
“A 10-year-old known asthmatic is seen in the physician’s office for severe wheezing. The patient complains of dyspnea, which has increased in severity over the past eight hours despite taking her normal asthma medications. Exam reveals that the patient is experiencing an acute exacerbation of asthma … The decision is made to place the patient on CBT with albuterol sulfate (5%), 20 mg per hour. An assessment is performed every 15 minutes … With no improvement in peak flow rate at the end of one hour, the physician increases the dosage to 25 mg/hour. A peak flow rate is measured every hour following this increase with steady improvement. Four hours following the initiation of DBT, the peak flow rate is 83% of predicted ….”
In this case, proper coding for four hours of continuous inhalation treatment would be 94644, 94645 x 3.
Take note: Inhalation treatment codes 94640 and 94644, +94645 have no physician work value, but do have practice expense value.


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4 Responses to “Select the Appropriate Inhalation Treatment Code”

  1. amanda says:

    This was a very good article.

  2. Nornacis Jusino says:

    Is very Intrested the article and the way we need to code

  3. Allison says:

    I see the last comment was from 2010, are we still not to code 94640 and 94644 on same day?
    Thank you,

  4. Rochelle Walker says:

    Thanks Great Information, one question, is the medication coded separately or a part of the inhalation treatment.