Medicare modifier guide

What each modifier means, when to use it and exactly how it changes Medicare payment.

59When to Use It and How It Affects PaymentModifier 59 tells Medicare two bundled procedures were separate and distinct. When it applies, when an X modifier fits better, and the NCCI denial traps.
25When to Use It and How It Affects PaymentModifier 25 marks a significant, separately identifiable E/M visit on a procedure day. Medicare's rules, when 57 or 59 fits instead, and the classic denial.
24Unrelated Visits in the Postoperative PeriodModifier 24 gets an unrelated E/M visit paid during a surgery's global period. Medicare's rules, the diagnosis that proves it, and when 24 is the wrong choice.
26Professional Component Billing ExplainedModifier 26 bills only the physician's interpretation of a test. Which codes accept it, how Medicare splits payment from TC, and when to bill globally instead.
51Multiple Procedures and the 50% ReductionModifier 51 flags additional procedures in one session. How Medicare ranks and pays them at 100% and 50%, which codes are exempt, and if Medicare needs it.
KXMedicare Therapy Threshold Rules for 2026The KX modifier attests that Medicare's policy requirements are met. How it works with the 2026 therapy threshold, the $3,000 review level, and DME claims.
95Telehealth Billing Rules for 2026Modifier 95 marks a telehealth service done by live audio and video. How Medicare uses POS 02 or 10 instead, what each pays, and what other payers expect.
52Reduced Services and How Medicare PaysModifier 52 reports a service that was partly reduced or not completed, without anesthesia issues. Medicare's documentation rules, payment, and the 53 line.
76Repeat Procedure by the Same PhysicianModifier 76 reports a procedure repeated the same day by the same practitioner. How to bill the lines, how Medicare pays, and when 77, 91 or 59 fits instead.
78Return to the OR During a Global PeriodModifier 78 bills an unplanned return to the OR for a related problem in a global period. What Medicare pays, what counts as an OR, and when to use 58 or 79.
50Bilateral Procedures and the 150% RuleModifier 50 reports the same procedure on both sides of the body. Which codes take it, how Medicare pays 150% on one line, and when RT and LT fit instead.
79Unrelated Procedure During a Global PeriodModifier 79 marks a procedure unrelated to an earlier surgery's global period. When to use it, how Medicare pays it, and 79 vs 58 vs 78 with knee examples.
22Increased Procedural Services and PaymentModifier 22 asks for more than the fee schedule amount when a surgery took far more work. Medicare's documentation rules, pricing, and common denial reasons.
GYStatutorily Excluded ServicesThe GY modifier tells Medicare a service is never covered by law, such as a routine physical. When to use GY, whether you need an ABN, and GY vs GA vs GZ.
XUUnusual Non-Overlapping ServiceModifier XU unbundles a service that doesn't overlap the main procedure's usual parts. CMS's definition, when XU fits better than 59, and the NCCI denial traps.
57Decision for SurgeryModifier 57 gets the visit that leads to a major surgery paid when it falls the day before or day of the operation. Medicare rules, 57 vs 25, and denial traps.
58Staged Procedure During a Global PeriodModifier 58 reports a planned, staged or more extensive procedure during a global period. When it applies, how Medicare pays it, and 58 vs 78 vs 79 explained.
GAWaiver of Liability (ABN on File)The GA modifier tells Medicare a signed ABN is on file for a service that may be denied as not medically necessary. When to use GA, ABN rules, and GA vs GZ.
JWDiscarded Drug AmountsThe JW modifier reports the discarded part of a single-dose vial so Medicare pays for it. How to bill JW on two lines, when to use JZ, and the 2026 rules.
53Discontinued ProcedureModifier 53 reports a procedure the physician started but had to stop. When it applies, how Medicare pays an incomplete colonoscopy, and 53 vs 52, 73 and 74.
93Audio-Only TelehealthModifier 93 marks a telehealth visit done by phone or other audio-only link. When Medicare allows audio-only care, billing 99214 with 93, and 93 vs 95 vs FQ.
JZZero Drug Wasted AttestationThe JZ modifier attests that no drug was discarded from a single-dose container. Who must use JZ, how it differs from JW, and claim returns without it.
TCTechnical Component Billing for MedicareModifier TC bills only the technical component of a test: equipment, staff and supplies. Who bills it, which codes accept it, and how Medicare reduces it.
GPPhysical Therapy Plan of CareThe GP modifier marks services delivered under an outpatient physical therapy plan of care. Who must use GP, how it pairs with CQ and KX, and GP vs GO vs GN.
80Assistant Surgeon Payment RulesModifier 80 bills an assisting surgeon. Medicare pays 16% of the surgery's fee schedule amount for approved codes. Indicators, rules and 80 vs 82 vs AS.
77Repeat Procedure by Another PhysicianModifier 77 reports the same procedure repeated on the same day by a different physician. When to use it, 77 vs 76 and 91, and why it does not bypass NCCI.
ASPA, NP and CNS Assistant at SurgeryThe AS modifier bills a PA, NP or CNS who assisted at surgery. Medicare allows 85% of the 16% physician rate, or 13.6% of the surgery. Rules and AS vs 80.
91Repeat Clinical Lab TestModifier 91 reports a lab test repeated the same day to get a new result for treatment. Medicare rules, when 91 is not allowed, and 91 vs 59, 76 and 77.
QKMedical Direction of 2–4 Anesthesia CasesQK bills an anesthesiologist medically directing two to four concurrent cases, paid 50% of the personally performed rate. The seven rules, ratios and QK vs QY.