Obstructive sleep apnea (OSA) is a treatable cause of daytime sleepiness and associated medical problems that can negatively impact soldier readiness and performance. This study examined adherence to positive airway pressure (PAP) by soldiers who were newly diagnosed with OSA and prescribed PAP therapy and participated in a Knowledge, Skills, and Attitudes (KSA) behavioral intervention class. The KSA was a one-time, interactive 90-minute class attended by up to 10 patients per class. PAP adherence was examined using Medicare standard at 30-, 60-, 90-, and 180 days post class. The analytic sample comprised 379 active duty patients (93% men; mean age 40.21 ± 8.06) categorized into 3 groups: KSA (n = 235), did not show (DNS; n = 61), and mandatory education class (MEC; n = 83). The MEC group comprised patients from an education class in a previous year. Baseline scores on the apnea hypopnea index, body mass index, sleepiness, insomnia severity, and age were non-significant among the 3 groups. At 30 days, significantly more patients in KSA (48%) and MEC (51%) were adherent than the DNS group (16%). At 60 days, the adherence rates for the KSA, DNS, and MEC were significantly different at 39%, 22%, and 27%, respectively. At 90- and 180 days, the adherence rates among the KSA, DNS, and MEC groups did not differ significantly at 34%, 17%, and 26% (90 days) and 34%, 27%, and 25% (180 days), respectively. Consistently, more patients in KSA were adherent than those in DNS and MEC, except at 30 days. Additionally, adherence rates for KSA intervention declined more gradually over the 6 month period. The mean PAP usage on nights used was 4.6 hours that computed to a 34% non-use rate based on an optimal 7-hour/night sleep time. KSA could be a behavioral intervention that enhances PAP adherence with a booster session implemented at the 90 days mark.