Medicare global surgery - ZZZ
Global indicator ZZZ: no period of its own.
How CMS treats add-on surgical codes inside the global period of the primary procedure.
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Result
What ZZZ means
ZZZ marks a code related to another service that is always included in the global period of the other service (Chapter 23, section 50.6). The manual adds that physician work is associated with intra-service time and in some instances post-service time.
How it is paid
ZZZ codes are surgical add-on codes always billed with another service. There is no postoperative work included in the fee schedule payment for a ZZZ code. Payment is made for both the primary and add-on codes, and the global period assigned to the primary code applies (Chapter 12, section 40.1; MLN booklet).
Modifier 26
The MLN booklet says providers can sometimes use modifier 26 with global surgery indicator ZZZ, and points to Addendum B of the physician fee schedule final rule for the year to see which procedures do.
Codes CMS has named
The booklet sets CPT Category III codes 0437T, 0439T and 0443T to ZZZ global surgery days. Other codes are listed as YYY or XXX. See YYY.
Practical reading
- Do not count days for a ZZZ code. Count from the primary procedure using its indicator.
- CMS applies the global period assigned to the primary code, not a separate count for the add-on.
- Use the global period calculator with the primary code's indicator.
- CMS describes ZZZ codes as add-on codes that are always billed with another service.
Worked example
A primary procedure with a 090 indicator is done January 5, with an add-on carrying ZZZ. The add-on is paid in addition to the primary code. Its global period is the primary period: January 4 through April 5. The row asked about ZZZ alone; the page gives the full table so ZZZ can be compared with 000, 010, 090, MMM, XXX and YYY.
FAQ
What does ZZZ mean in the global surgery field?
The code is related to another service and is always included in the global period of that other service.
Does a ZZZ code have its own postoperative period?
No. There is no postoperative work in the fee schedule payment for a ZZZ code. The global period assigned to the primary code applies.
Is a ZZZ code paid separately?
Yes. Payment is made for both the primary and the add-on code.
Can modifier 26 be used with ZZZ?
Sometimes. CMS says to check Addendum B of the fee schedule final rule for the year to see which procedures use modifier 26.
Can a ZZZ code be billed alone?
No. CMS describes them as add-on codes that must be billed with another service.
Sources
Retrieved 2026-11-02 from the CMS documents below. Indicator meanings are paraphrased from the CMS definitions; no AMA CPT descriptors are reproduced. CMS revises the fee schedule and its manuals, so check the current text.
- CMS: Medicare Claims Processing Manual, Chapter 23, Fee Schedule Administration and Coding Requirements (Rev. 13701, issued 06-16-26): section 50.6, Global Surgery value ZZZ (retrieved 2026-11-02).
- CMS: Medicare Claims Processing Manual, Chapter 12, Physicians/Nonphysician Practitioners (Rev. 13753, issued 05-07-26): section 40.1, add-on codes (retrieved 2026-11-02).
- CMS: MLN907166, Global Surgery booklet (December 2025): FAQs, ZZZ codes and modifier 26 (retrieved 2026-11-02).
Not legal, billing or medical advice
This page explains published Medicare fee schedule indicators and CMS manual text. It cannot see your claim, your contract or any payer's policy, and the amounts it shows are illustrations, not claim prices. Confirm with your Medicare Administrative Contractor or payer before you bill, resubmit or appeal. Everything runs in your browser; nothing you enter is sent anywhere.