What is the difference between a line item, MUE edit and a date of service edit?

What do the different MUE Adjudication Indicators (MAI) for service lines and service dates mean on the Medically Unlikely Edits (MUE)?

In 2013, CMS introduced an additional element to the Medically Unlikely Edits, the MUE Adjudication Indicator (MAI). There are two types of MUE edits.

The first type (indicator value “1”)is a quantity of service limit that applies just to services on a single claim line. So for example, it may limit the number of services reported on a service line to 4 units. If the same HCPCS code is used to report services as separate line items appropriately, they would not be combined under the one limit.


  • 82374: Carbon dioxide (bicarbonate)
  • MUE: 2, maximum of 2 service units
  • MAI: 1, limit per line of service
  • Summary: 82374 may be reported up to twice per service line as appropriate.

The second type (indicator values “2” and “3”) is based on the date of service, and applies to all reporting of that HCPCS code on a service date, even if broken into separate line items or claims.


  • G0422: Intensive cardiac rehabilitation; with or without continuous ECG monitoring with exercise, per session
  • MUE: 6, maximum of 6 service units
  • MAI: 2, absolute coverage limit per day
  • Summary: G0422 may be provided a maximum of 6 times per day as appropriate. Total restriction, no exceptions. Q9980: Hyaluronan or derivative, GenVisc 850, for intra-articular injection, 1 mg MUE: 50, maximum of 50 service units MAI: 3, suggested coverage limit per day Summary: Q9980 may be provided up to a maximum of 50 mg as appropriate. Higher amounts may be appealed based on strong clinical documentation and medical necessity.

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