I was diagnosed with asthma and retained by the Air Force with an ALC-C2. I can say that your commander's recommendation has a strong impact on your retention or separation. If your commander states that you are still able to do your job, your chance of being retained is high. However, if your commander states that you cannot do your job, you will either be separated or retrained, depending on the severity of your condition.
Addtionally, I feel that a large portion of whether you are retained or not depends on whether your condition is persistent, controllable and whether or not you require regular/daily medication. My condition is referred to as "mild persistent asthma", as I tend to always have a low-grade asthma reaction. It is well controlled with a daily inhaled anti-inflammatory, anti-histamines, and occasional pre-exercise albuterol. If your condition is severe and/or sporadic (asthma attacks out of the blue, or exercised induced), you will likely be separated.
The VA schedule of ratings is a great place to look to see how your disability can be rated. Most sporadic asthma conditions that only require occasional albuterol/rescue inhalers are rated at 10% and the individual is separated from duty with severance pay. If you require daily medication (anti-inflammatory or cortisteroid), your condition is generally rated at 30%. If you require even more severe medication, your rating could be 60% or even 100%. Mind you, 100% rating is where your condition regularly life-threatening and/or severely impacts your life style.
