<p>At our HS, all students take PSATs as sophomores and juniors  Both my kids took SATs in Jan of junior year.  My son (who is a very high scorer on standardized tests) took it in spring of his sophomore year, too, although I wouldn't recommend this for most students.  His January of junior year score was high enough that he did not need to take SATs again after Jan. </p>
<p>My daughter, who sounds more like your son, took the SATs in January of junior year (she had studied over the previous summer) and scored lower than she did on her PSATs in October of junior year (1260 on the SAT versus the equivalent of 1330 on the PSAT).  She studied some more and took it again in March, receiving a 1380 which she (and I) felt was sufficient for the colleges she was aiming for, and she did not take it again.  </p>
<p>There are two advantages to this strategy (if it works out for you).  She did not need to further stress about preparing for SATs after her junior year, and and she also knew what the scores she would be using to apply with were, so she knew which colleges were realistic targets for her before her senior year.</p>
<p>In her case, she was very busy during the summer before senior year and the fall of junior year.  It made life much simpler and easier not to have to retake the SATs and finalize her college list as a senior.  </p>
<p>The tradeoff in doing it this way is that there is a chance that scores will go up when retaking as a senior and that the list of colleges which are realistic targets will expand.  In my daughter's case, she felt that the stress and aggravation of retaking would not be worth it for her, as she was happy with her scores for the schools she was interested in.  Obviously, for students needing to raise their scores to get into the range for the schools they are interested in, the situation would be different.</p>
<p>In any case, I don't see the disadvantage of taking the SAT in January of junior year, as it would just mean that the student took it three times if they ended up retaking as a senior, and I believe that three times is not considered excessive for the SATs.</p>
<p>Edit - Neither of my kids took the ACT, as it was not common around here at the time.  I have no idea how my daughter would have done on it - many people have reported greater success for some kids on it vs. SAT.</p>