A single morpheme exists which expresses all of Tense, Mood, and Agreement. For example, in Wari (Bickel & Nichols 2008), a morpheme <i>na</i> expresses realis mood, non-future tense, and 3-singular agreement. 
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<b>Reference</b><br>
Bickel, Balthasar & Nichols, Johanna. 2008. Exponence of Selected Inflectional Formatives.
In Haspelmath et al, chapter 21.
Available online at <a href="http://wals.info/feature/21">http://wals.info/feature/21</a href>.