The part you need
Medify's three-stage cartridge for the MA-40: a pre-filter, an H13 HEPA stage and what Medify calls a "Substantial Carbon Filter", in one piece.
Medify Air says: 3,000 hours of use, per Medify's own FAQ.
Price, seller and package contents change. Check the variant on Amazon before you buy.
Fits these models
Does NOT fit — commonly confused
Variants Medify Air sells
Units we have researched that take this filter: Medify Air MA-40 .
Medify's three-stage cartridge for the MA-40: a pre-filter, an H13 HEPA stage and what Medify calls a "Substantial Carbon Filter", in one piece.
What makes this filter worth its own page is not the media. It is that Medify is the only manufacturer in this catalogue that states its replacement interval in HOURS OF USE rather than in months — which is the figure every other brand leaves out and the reason none of their month-based numbers can be compared with each other.
3,000 hours of use, per Medify's own FAQ. Not months — hours.
That is worth dwelling on, because it is the opposite of how every other brand on this site publishes. A month-based interval hides the assumption that makes it meaningful: run a unit four hours a day and 3,000 hours is roughly two years; run it around the clock and it is about four months. Same filter, same number, wildly different calendars — and Medify is letting you do that arithmetic instead of doing it for you and hiding the inputs.
Run it yourself: 3,000 divided by the hours you run the unit each day gives you the days.
⚠️ The figure is per model and not uniform: Medify states 3,000 hours for the MA-18, MA-25, MA-35 and MA-40, and 2,500 hours for the MA-50.
Steps as documented by Medify Air. If the light stays on after this, the troubleshooting below covers why.
Medify's published instruction for the MA-40 is to "install a new genuine Medify replacement filter". It states no position on how third-party filters perform, and as everywhere in this category none of them carries an independent performance measurement, so there is nothing to compare.
What Medify IS explicit about is maintenance, and it is worth quoting because it contradicts what people try: for the MA-35 and MA-40, "Do not vacuum or try and wash filter as it will clog filter". Note the reason it gives — not that cleaning is merely ineffective, but that it makes the filter worse.
That is Medify Air’s stated position, reported as theirs. We have not tested third-party filters and make no claim about how well they work.
| Symptom | Why it happens | What to do |
|---|---|---|
| Wanting to know how long the filter lasts in months and not finding an answer. | Medify publishes hours, not months, and does not convert. | Divide 3,000 by the hours you run the unit per day. Four hours a day is about two years; continuous running is about four months. That spread is exactly why other brands' month figures are hard to trust. |
| Vacuuming the filter to stretch it further. | It looks like a stiff pleated element that could be cleaned. | Medify says plainly not to, for the MA-35 and MA-40, and gives a reason: it will clog the filter. On this model there is no maintenance that extends life. |
| The filter indicator stays on after a change. | It is an hours counter and does not clear itself. | Hold the dimmer or filter button for 3 to 5 seconds with the unit on. |
| Using another Medify model's interval or reset method. | Medify's figures and gestures differ across its own range — 2,500 hours on the MA-50, a different button on the MA-112. | Check the figure for your exact model number. Within this brand the range is not interchangeable in any respect. |
Price, seller and package contents change. Check the variant on Amazon before you buy.
Checked against the manufacturer's own pages. We did not test this filter. Nothing here is a measurement of ours: every figure is either documented by the manufacturer or published by an independent standards or testing body, and where the two disagree this page says so.
