I'm on medicare. When I first started on this fun journey Inogen was not covered by my insurance so I paid for the biggest portable they had. Along with 'lifetime' warranty. Assume a large number of us are considered short timers :) I'm on my 4th one now. Pretty much don't use it. Two reasons, 1, don't trust it, first one failed on the road 400 miles from home. (had a tank backup) 2. need more than the 5 it produces now. Being pulse the numbers are just relative. Talking with Lincare sometime ago they said medicare will pay for a portable but not if you want tanks also. I have a 10L in home concentrator, run about 5.5L. I use tanks mostly when out and about. In the car I use E size mostly on 4L. Average 4 a week. Outside farming and in the shop I use C tanks with an electronic pulse regulator. Use about 12-14 a week. (Have not done well with the mechanical pulse regulators, maybe I'm too hard on them)

Ask your pulmonologist or ARNP fora recommendation. Do you have your own pulse oximeter. If not, very inexpensive on Amazon. Keep track of your O2 stats.

Ur doctors can write a prescription for u to get one.

The easy way is to just go on line and order one and pay for it out of pocket. So (Phone number can only be seen by the question and answer creators) the last I checked. Some insurance companies will pay for one. When my last large concentrator was delivered, I had one before where the contract with Medicare had expired, I also got 6 small tanks that operate on pulse or continuous flow. They weigh about 5 pounds each and a harness was provided also. Or rather a back pack. Anyway, I was glad to get them because if the electricity goes off, I've still got O2 available. They call me every two weeks to see if I need more O2. If I do, they deliver it. I live in a very small rural village really, so I am grateful for this service. Otherwise, it would mean a 50 mile trip to Amarillo to pick up supplies every few days or so. Good luck. Hopefully, your medicare will provide you with the portable unit.