No, this is not true. The rule is that once you are approved for a Durable Medical Device, you have to get that script for the device filled within 6 months. It has nothing to do with supplies. For instance, my brother was approved for a power wheelchair, but because he is delayed in moving to Assisted Living, he's going to have to go through the approval process AGAIN because he didn't buy it within 6 months. This is because the rules are based on 'medical need' and their assumption is that if you didn't get it within 6 months, you don't need it. Doesn't matter that you have to come up with $$ to pay that 20%.
All that said, it is up to the DME to interpret the Medicare rules. For instance, one place will send you supplies every month, while another interprets the very same rules and sends them every 3 months. Even the SAME COMPANY will interpret the rules differently! My bro and I both had Lincare, through the same office but different reps. He was able to get his supplies every 3 months, but I couldn't get my rep to budge and am bugged monthly for supplies.
Apria DOES require a new prescription every year to continue to provide supplies. This is now a Medicare mandate. However, that prescription doesn't have to be through the sleep center. It can be through your primary. Most of the online retailers (ones that do not deal with Medicare or insurance) do not have that mandate and will provide supplies based on your prescription until their auditor says they need a new one. If you want to lower your frustration, just order the filters.
That's an order, right?