Global Surgery Period & Required Modifier

Surgical global-period check: whether a subsequent-service date falls inside the global window and, by the nature of the service, whether it is separately billable and with which modifier.

Open the tool → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Surgery date: 2026-01-01
Global period indicator from the MPFS: 090 -- major surgery (90-day, + 1 preop day)
Subsequent service date: 2026-02-01
Nature of the subsequent service: Unrelated E/M visit

Result: Inside the 90-day global (window 2025-12-31 through 2026-04-01); an unrelated E/M is separately billable with modifier 24.

The tool opens with these values already filled in. Replace them with your own.

What you enter

Surgery date (YYYY-MM-DD)
Global period indicator from the MPFS
Subsequent service date (YYYY-MM-DD)
Nature of the subsequent service

How this is calculated

CMS Pub. 100-04 Ch. 12 40 (global surgery package); MLN Global Surgery Booklet. GLOB DAYS 000/010/090 = 0/10/90 postoperative days (090 adds 1 preoperative day); XXX/YYY/ZZZ/MMM do not carry a fixed day count. Post-op modifiers 24/58/78/79; pre-op 57/25. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.