All standard-size Austin Air units are compatible with any standard-size filter. Meaning, if you originally purchased a HealthMate® unit and want to upgrade to an Allergy Machine®, you only need to buy a replacement Allergy Machine® filter for the switch.

When placing your order for a replacement filter, it’s important to double-check that you’ve selected the correct size and filter type before finalizing your purchase. Filters that are incorrectly ordered may be subject to a restocking fee if returned.

To confirm the size of your current filter, look for a label on the bottom of your unit. If it displays the model number "HM400," it indicates you need a standard-size filter.