Hanafi
The sources give no view for it here.
أقسام الصيام
هل الصيام قسمان: فرض وتطوع، دون قسم ثالث؟
Each school’s answer
In our wordsHanafi
Not stated in the sources
Maliki
Not stated in the sources
Shafi'i
Not stated in the sources
Hanbali
Not stated in the sources
The texts
٧٢٦ - مَسْأَلَةٌ: الصِّيَامُ قِسْمَانِ فَرْضٌ، وَتَطَوُّعٌ، وَهَذَا إجْمَاعُ حَقٍّ مُتَيَقَّنٍ، وَلَا سَبِيلَ فِي بِنْيَةِ الْعَقْلِ إلَى قِسْمٍ ثَالِثٍ؟ [مَسْأَلَةٌ صِيَامُ شَهْرِ رَمَضَانَ]
From the schools’ own books
Maliki
The sources give no view for it here.
Shafi'i
The sources give no view for it here.
Hanbali
The sources give no view for it here.
What is «in our words» is our standard wording; the books’ texts stay as they are.