Thank you for your question. The use of the “Unfractionated Heparin for VTE Prophylasis ingredient specific” value set with the QDM construct “Medication, Order not done” is indeed intentional. This value set contains, as the name indicates, ingredient-level medications (e.g. heparin sodium, porcine) and it is used to represent higher-level, less granular forms of low dose unfractionated heparin (note that the value set name does not include any reference to the dose because ingredient-level RxNorm terms do not include medication strength). Ingredient-specific value sets were introduced in the April 2014 release to address a documentation granularity issue when capturing reasons for not ordering a particular medication. In the past, “prescribable” RxNorm terms were used for this purpose (i.e., the “Low Dose Unfractionated Heparin” value set). This caused issues due to the unnaturalness of documenting a reason for not prescribing, for instance, heparin sodium, porcine 5000 UNT/ML Injectable Solution. Please let us know if this clarifies this issue for you.