Modifier 59 vs XE/XS/XP/XU Selector

Modifier 59 vs XE/XS/XP/XU Selector - a deterministic tool in Sophie Well's Billing & Reimbursement group.

Open the Modifier 59 vs XE/XS/XP/XU Selector → Runs in your browser. No signup, no tracking.

What this is

Modifier 59 vs XE/XS/XP/XU Selector is one of 230 deterministic tools in Sophie Well's Billing & Reimbursement group. Modifier 59 vs XE/XS/XP/XU Selector - a deterministic tool in Sophie Well's Billing & Reimbursement group.

When to use it

Use this tool when you need a quick, citable reference. Every calculation runs entirely in your browser - no inputs leave your device, no account is required, no AI is involved. The site enforces a strict Content Security Policy and ships no analytics or third-party CDN.

References

CMS MLN "Proper Use of Modifiers 59 & X{EPSU}"; Pub. 100-04 Ch. 23. XE = separate encounter, XS = separate structure/site, XP = separate practitioner, XU = unusual non-overlapping; 59 only when no X-modifier fits. CMS prefers the specific X-modifier over 59. Read the source ↗

Worked example: Modifier XS -- the most specific X{EPSU} modifier for a separate anatomic structure/site.

Sophie Well is a reference and educational tool. Not medical, legal, or financial advice. Does not replace clinician judgment, professional billing review, or legal counsel.

Built by Clay Good. Source on GitHub.