Semantics of Modifiers

[nmaylevc]

The latest schemas have improved how modifiers are disclosed in the JSON template and we very much appreciate these improvements, however, there are still questions as to how to users of the data should interpret the different forms of disclosures and how creators of files should encode the data.

In all of the templates there is the ability to describe a modifier (or possibly multiple modifiers) independent of any billing codes. I think of these as "global modifier" descriptions -- they are not tied to a specific code and are thus potentially applicable to many or all codes.
In CSV templates this can be done by encoding the modifier in the modifiers and not including any billing codes (see item 11 in Conditional Requirements https://github.com/CMSgov/hospital-price-transparency/tree/master/documentation/CSV#conditional-requirements). In the JSON template, these can be encoded in the "Modifier Information Object". Associated with the modifier (or modifiers in CSV templates) can be modifications to the standard charges.

There are a few differences between the templates with regard to the global modifiers:

• JSON provides a way to encode a description of the modifier itself (the name of the modifier); the CSV templates do not unless the description field on this row(s) was intended to be the description of the modifier(s) itself. This should be clarified.
• the CSV templates allow for multiple modifiers; the JSON template schema only appears to allow for one modifier code.
• the JSON template only has a provision for a textual (string) description of how the charges are modified (see Modifier Payer Information ); the CSV template allows any or all of the types of negotiated charges to be encoded (dollar, percentage, algorithm) and associated with this modifier. This CSV format may be easier to interpret since it may not be free text.
• The JSON format doesn't provide a way to express how the gross charge and cash charge may be modified, it has the description of the modification to charges associated with payer and plan, so only negotiated charges.
• The CSV template does not describe the semantics of the standard charge fields on a "global modifier". One might assume that the most useful charge type would be percentage, if that was defined to be interpreted as a percentage that was applied to the specific standard charge associated with a specific code. However, the intended interpretation of these fields is not defined and this leads to ambiguity and confusion
• The JSON format doesn't specify that the payer names and plan names in the Modifier Payer Information should match the payer and plan names used on items. We have seen cases where it doesn't.

Each template also provides a mechanism for encoding an item with a set of codes and with one or more modifiers. I refer to these as "Local Modifiers". These items have encoded the standard charges that are specific to the billing codes, setting, description etc. and when the set of modifiers are applied. In JSON the local modifiers are described using the modifier_code field on a Standard Charge Object. In the CSV templates these are encoded in the modifiers field.

There are some differences between templates in these too:

• CSV templates do not specify how to encode multiple modifiers -- should they use pipe characters between the codes to delimit them; in the JSON template it is explicitly an array of modifiers
• in the JSON template, the description of the field connects them to the global modifier describes when it states: "An array of strings, each of which should be a modifier code present in a Modifier Information object." The CSV template doesn't address the issue of the relationship between local modifier codes and any global modifiers.

(The prior JSON template didn't include a way to encode a local modifier and several hospitals used a user-defined fields instead. So, it is great that there is now a standard for this, however, it isn't clear that every hospital will notice this change and update their MRFs to use the new mechanism.)

None of templates as described on GitHub address the issue of how to understand the case where there is both a Global Modifier applies to an item and there is a Local Modifier(s). For examples, if modifier 50 is globally defined to increase the standard negotiated charge by 150% and there is an item with the code of 29805 and with a 50 modifier with a different percentage change. The question is: does a local modifier supersede a global modifier? That would seem like a reasonable interpretation, but again clarification would be very helpful.

While global modifiers are a compact way to represent how a modifier adjusts the standard charges when there is a consistent adjustment across all relevant codes, it does introduce challenges. In particular, it is hard to be sure which items a global modifier may apply to.

How are people handling these issues with modifiers?
Would it be possible for the CMS to update the GitHub descriptions, have a webinar or issue a FAQ that clarifies these issues?