No. There is no minimum denominator requirement. A sample of 30 (or more, because this increases the reliability of the sample) is expected to ensure statistical soundness, but there may be cases where it may be appropriate for the denominator to be <30. NCQA requests practices enter an explanation in the Notes from the Organization section in QPASS in this case.
If a practice reports a denominator <30 without a note, the evaluator may contact the practice to confirm data accuracy and to understand the data. The evaluation will be returned to the practice so they can enter an explanation in the Notes from the Organization section for the cited criteria.