ICD-10 M45.A0
Billable / Specific HCC v28: 40Non-radiographic axial spondyloarthritis of unspecified sites in spine
About ICD-10-CM M45.A0
ICD-10-CM code M45.A0 represents Non-radiographic axial spondyloarthritis of unspecified sites in spine. This is a billable/specific code in the Musculoskeletal and Connective Tissue chapter (block M45). The 2026 edition of ICD-10-CM M45.A0 became effective on October 1, 2025.
Coding Tips for M45.A0
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
M45.A0 is a CMS-HCC v28 risk-adjustment code (category 40). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Medicare LCD Coverage for M45.A0
Local Coverage Determinations (LCDs) from CMS MACs that list M45.A0 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing M45.A0.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but M45.A0 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with M45.A0
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To M45.A0
Other codes in section M45-M49 (Spondylopathies).
ICD-10 M45.A0, Billing FAQ
Is ICD-10 code M45.A0 billable? +
Yes, M45.A0 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
Does M45.A0 affect Medicare Advantage HCC risk adjustment? +
Yes. M45.A0 maps to CMS-HCC v28 category 40. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Get the full PayerReady toolkit
Free access to CPT/ICD-10 lookup, denial appeals, fee comparator, and claim auditing with credentialing enrollment.
Start free →Run this code through our claim audit tool
Check NCCI bundling, MUE limits, and modifier logic before submission.
Try the auditor →Did this page help?
Quick signal so we know what to improve.
If you want a code reference page that doesn't exist yet, email coding@payerready.com.
Tell us what's missing or wrong: coding@payerready.com. We respond within 5 business days.
Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
Powered by 11K CPT · 98K ICD-10 · 860K MPFS rates · 4.5M NCCI edits · 9.5M NPIs. Our data methodology · About our coding team