Introduction <p>The journey to axial spondyloarthritis (axSpA) diagnosis is often prolonged, and delayed diagnosis has been associated with poorer outcomes and increased healthcare costs. This study aimed to characterize the patient diagnostic journey in axSpA and associated healthcare resource utilization (HCRU) and costs in the US.</p> Methods <p>This observational, retrospective US MarketScan^® study utilized insurance claims data from the Commercial/Medicare Supplemental (January 2008–March 2023) and Medicaid (January 2008–December 2022) databases to assess the time to diagnosis in adult patients with back pain onset prior to a new axSpA diagnosis. This study evaluated the time to axSpA diagnosis from the earliest back pain diagnosis, and the diagnostic journey through the number of consultations with healthcare professionals (HCPs) for back pain, diagnostic tests, and imaging procedures. Back pain-related HCRU and costs were assessed, as well as pharmacy claims during this period.</p> Results <p>Of 97,469 patients included, 29.0% experienced time to diagnosis of ≥ 6&#xa0;years, with a mean (standard deviation) of 4.5 (2.8) years to diagnosis. Prior to axSpA diagnosis, patients saw an average of 4.57 HCPs annually and had 20.7 back pain-related visits overall for back pain-related causes. Between the earliest back pain diagnosis and axSpA diagnosis, 55.9% of patients experienced &gt; 10 back pain consultations, and patients underwent a range of diagnostic tests and imaging procedures. The median sum of non-capitated back pain-related costs up to axSpA diagnosis was $883.19 per patient per year, plus $1127.57 per patient per year for pharmacy prescriptions.</p> Conclusions <p>This study shows that diagnostic delay is a challenge for patients with axSpA in the US, despite numerous back pain consultations, specialist visits, and diagnostic tests. These findings highlight the urgent need for strategies to enhance recognition of axSpA and improve the patient diagnostic journey.</p>