If you’re planning on doing medical billing and sending in claims for oxygen, you better make sure you’ve had plenty of sleep the night before. Oxygen billing is probably the most complex of all the medical billing procedures because of certain conversions and calculations that need to be done in regard to the oxygen itself. In this installment of our series on medical billing and the electronic transmission of claims using NSF 3.01 specifications, we’ll be covering the GX0 record, picking up with field number 14.

GX0 field 14, positions 125 - 127, is the oxygen flow rate. This tells the carrier how many liters per minute the patient is supposed to receive. The valid values are 001 - 999. If the patient is going to be getting less than one liter per minute than the software needs to enter 00X.

There are some notes that are important about this field, as it is one of the most important fields on this CMN.

If you’re billing for an oxygen concentrator, the concentrator being given to the patient must go along with the flow rate prescribed by the doctor. This is especially critical when billing for flows greater than 4 liters per minute and less than 1 liter per minute. Also, if you’re billing oxygen for a flow rate greater than 4 liters per minute, the date the test was performed must be filled in. Use field GX0-20 for this. Also, flows of greater than 2 liters per minute will usually require a review by the insurance companies medical staff.

GX0 field 15, positions 128 - 129, is the frequency of use. This field tells the carrier how many times per day the patient is to use the oxygen. Just a note. This field is usually only filled in if the doctor prescribed oxygen use during certain times, such as when the patient is exercising, sleeping, etc.

GX0 field 16, positions 130 - 131, is the duration of use. This field tells the carrier how long in hours the patient is to use the oxygen for each use. If the number of hours is less than 10, then the field needs to be left zero filled. So 4 hours would be transmitted as 04.

GX0 field 17, positions 132 - 134, is the arterial blood gas at 4 LPM. This field tells the carrier what the blood tests results were for arterial gas when the patient was given oxygen at a rate of 4 liters per minute.

GX0 field 18, positions 135 - 137, is the oxygen saturation at 4 LPM. This field tells the carrier what the blood test results were for oxygen saturation when the patient was given oxygen at a rate of 4 liters per minute.

GX0 field 19, positions 138 - 145, is the date the patient was tested on 4 LPM. This field tells the carrier the date that the patient was tested for the 4 LPM tests. This date can be transmitted as yyyymmdd or mmddyyyy, depending on the carrier requirements.