Medical oxygen therapy is a regulated treatment for individuals whose bodies cannot absorb enough oxygen from the atmosphere. While the air we breathe contains approximately 21% oxygen, medical-grade oxygen is highly purified, typically containing at least 87% to over 99.5% oxygen, depending on the source. This concentrated gas is classified as a prescription drug due to its potent effect and the potential for harm if used improperly, such as causing oxygen toxicity or lung injury. Obtaining oxygen tanks, or any similar delivery system, is therefore a process strictly managed by medical oversight and federal regulation.
Obtaining a Medical Prescription
The first step in obtaining medical oxygen is a formal prescription from a licensed physician. This ensures the patient receives the correct therapy and flow rate. The physician must first establish medical necessity, which often involves specific testing to confirm low blood oxygen levels, a condition known as hypoxemia.
Testing typically includes pulse oximetry, a non-invasive measurement of blood oxygen saturation, or an arterial blood gas (ABG) test for a more direct reading. For insurance providers, including Medicare, to cover the cost, the patient’s oxygen saturation must generally fall below a certain threshold while at rest, during sleep, or with exertion. The prescription must specify the required flow rate, measured in liters per minute (LPM), and the specific conditions for use. This documentation is mandatory for securing the equipment and for any subsequent insurance claim.
Primary Supply Chains: Durable Medical Equipment Providers
The primary source for long-term home oxygen equipment is a Durable Medical Equipment (DME) provider. These suppliers are responsible for providing, setting up, and maintaining the equipment prescribed by the physician. The process begins when the doctor sends the oxygen prescription and supporting medical documentation directly to the chosen DME company.
The DME provider handles insurance verification, confirming coverage under policies like Medicare Part B, which classifies oxygen equipment as DME. Following approval, the supplier delivers the equipment and provides a technician, often a respiratory therapist, to set up the system and train the patient and caregivers on its use. For tanks and liquid systems, the DME company also manages the ongoing delivery schedule for refills or exchanges. The supplier must ensure the provided equipment meets the patient’s mobility needs, both inside and outside the home, as prescribed.
Choosing Between Tanks, Concentrators, and Liquid Oxygen
DME suppliers offer three main types of oxygen delivery systems, each with distinct features that should align with the patient’s lifestyle and medical needs. Traditional compressed gas tanks store oxygen under high pressure (typically around 2,200 PSI) and provide gas with a high purity level, often over 99.5%. These tanks are simple to use and are often used for portable or backup purposes, but they are finite and require regular delivery and exchange once depleted.
Oxygen concentrators do not store oxygen but instead filter it from the surrounding air. These electrically powered devices separate nitrogen from the air to deliver a continuous supply of concentrated oxygen, usually between 87% and 95.6% purity. Concentrators eliminate the need for refills but require a power source, making a backup system advisable in case of an electricity outage.
A third option is liquid oxygen, where the oxygen is cooled to an extremely low temperature to maintain a liquid state. Liquid oxygen systems are highly space-efficient, with one liter of liquid being equivalent to 860 gaseous liters, and they can deliver high flow rates for patients with severe needs. However, the liquid form is stored in specialized, vacuum-insulated containers and will naturally vent over time, meaning it must be used or it will evaporate.
Accessing Oxygen for Non-Standard Use Cases
Procuring oxygen for travel or high-altitude environments involves considerations separate from the standard home DME supply chain. For air travel, only specific, FAA-approved Portable Oxygen Concentrators (POCs) are permitted on commercial flights. Airlines require passengers to notify them in advance and carry a prescription or a medical form signed by a physician, often including a High-Altitude Simulation Test (HAST) result to determine in-flight oxygen needs.
Patients needing oxygen for travel must ensure they have enough battery life to cover 150% of the planned flight time, as the airline will not provide power or oxygen. For high-altitude sickness, oxygen can sometimes be rented from local suppliers in tourist areas, often using medical-grade equipment provided for short-term use. Over-the-counter recreational oxygen cans are also available, but they are not a substitute for medical-grade therapy and have limited efficacy in treating significant altitude symptoms.
For emergency short-term needs, such as transitioning from a hospital stay back home, the hospital discharge team directly coordinates with a DME provider to ensure a seamless setup. This prevents any gap in the patient’s supplemental oxygen therapy. In all non-standard scenarios, a valid prescription detailing the required flow rate and duration remains necessary for obtaining medical-grade oxygen.