Short answer: every Austin Air machine takes its own main filter, and the part number tells you which. The HealthMate takes the FR400, the HealthMate Plus the FR450, the Bedroom Machine the FR402, the Immunity Machine the FR444, the HealthMate Junior the FR200 and the HealthMate Plus Junior the FR250. The letter at the end is the color: A for black, B for white. The four full-size machines share one pre-filter (F400); the two Juniors share another (F200).
Which filter fits which machine
| Machine | Main filter | Main filter price | Pre-filter | Pre-filter price |
|---|---|---|---|---|
| HealthMate | FR400A (black), FR400B (white) | $394.99 | F400A / F400B | $34.49 |
| HealthMate Plus | FR450A (black), FR450B (white) | $444.99 | F400A / F400B | $34.49 |
| Bedroom Machine | FR402A (black), FR402B (white) | $544.99 | F400A / F400B | $34.49 |
| Immunity Machine | FR444A (black), FR444B (white) | $694.99 | F400A / F400B | $34.49 |
| HealthMate Junior | FR200A (black), FR200B (white) | $294.99 | F200A / F200B | $29.49 |
| HealthMate Plus Junior | FR250A (black), FR250B (white) | $344.99 | F200A / F200B | $29.49 |
| "it" | FR100B (HEPA only), FR100C (VOC carbon wrap) | $129.99 / $144.99 | F100B / F100C | $9.99 / $14.99 |
Prices are ours as of November 2, 2026, with free shipping. Each machine's filters are on one page: HealthMate, HealthMate Plus, Bedroom Machine, Immunity Machine, HealthMate Junior, HealthMate Plus Junior and "it".
How to find your model
- Check the label. The model and serial number are on the label on the machine. The model names match the table above.
- Check the old filter. The part number is printed on the filter. Order the same number.
- Not sure? Email a photo of the label to support@freshhomeair.com and we will tell you which filter fits.
The main filter and the pre-filter are different jobs
The main filter is the one that matters: it holds the HEPA and the carbon. On the HealthMate, HealthMate Plus, Bedroom Machine, Immunity Machine and the two Juniors, Austin Air designs it to last up to five years in normal home use. Heavy smoke, a renovation or a very dusty home shortens that.
The pre-filter is the outer wrap. It catches hair and large dust so the main filter does not clog early. Our filter pages suggest replacing it every 3 to 6 months, depending on your air and how much the machine runs. It is the cheap part, and keeping it fresh protects the expensive one.
Why the HealthMate and HealthMate Plus filters are not the same
They fit the same cabinet, but the carbon is different. The HealthMate Plus filter (FR450) has part of its carbon treated for chemical gases such as formaldehyde, which plain carbon holds poorly. That is the difference you are paying the extra $50 for. If you bought the Plus for chemical sensitivity, replace it with the FR450, not the FR400. The two machines are compared in HealthMate vs HealthMate Plus.
What the filters cost over five years
For a full-size machine, five years is usually one main filter plus about ten to twenty pre-filters. For the HealthMate Plus that is $444.99 plus $345 to $690 in pre-filters if you replace them at the 3 to 6 month pace. Many owners vacuum the pre-filter and stretch it. The full five-year math for every machine we sell is in air purifier filter replacement cost.
Common questions
Does the HealthMate filter fit the HealthMate Plus?
It fits the cabinet, but it is the plain-carbon HealthMate filter. To keep what the Plus was bought for, use the FR450.
What do the A and B mean on Austin Air part numbers?
The color of the filter: A is black and B is white, to match your machine.
Do all Austin Air machines use the same pre-filter?
The four full-size machines share the F400. The two Juniors share the F200. The "it" uses its own F100.
Do you sell genuine Austin Air filters?
Yes. We are an authorized Austin Air dealer, and filters ship from Austin Air with free shipping.
