I think people are losing sight of the situation here.
First, if OP's child never passed Algebra 1 in a Maryland Public School and passed it either in a private school or out of state/out of the country, then they are exempt from the Algebra test requirement. It's in this COMAR:
https://dsd.maryland.gov/regulations/Pages/13A.03.02.12.aspx
(2) Maryland Comprehensive Assessment Exemption Requirements.
(a) A student who transfers from a nonpublic school or a school out of State is exempt from one or more of the Maryland Comprehensive Assessments if, consistent with local school system policy and procedure, the local superintendent determines that the course taken is aligned with the relevant Maryland Comprehensive Assessment and awards the student credit for taking any of the courses aligned with the Maryland Comprehensive Assessments, that is, algebra, science, English, or government, or all of these, in accordance with the principles set forth in §B(2)(c) of this regulation.
What should have happened is if the STC or registrar saw that the student completed the course at an eligible institution, they should have submitted this student for exemption from the Algebra 1 test requirement. So the student didn't need to be tested in the ninth grade upon entering MCPS.
But the student was tested anyways in ninth grade. And for now and the near future, the graduation requirement is participation only. So the student should be marked as fulfilled, regardless of their score.
What sounds like is going on now is that the school is trying to boost their CCR numbers by having the student meet the proficiency level requirements. And should have nothing to do with their Algebra 1 graduation requirement, which should already be fulfilled.
I'm not really familiar with all of the criteria but the details about CCR are in here:
https://marylandpublicschools.org/stateboard/Documents/CCR-Standard-Policy-Adopted-03-2025-A.pdf
and page 9 lists several alternatives students can use to meet CCR standards starting this year. Some of which are:
-earning at least a 480 in the Reading/Writing and 530 in Mathematics in the SAT or PSAT
-earning a 3 or higher in one AP Math assessment and one ELA/Science/Social Studies assessment
-have a cumulative GPA of 3.0 or higher and have an A, B or C in a higher level math course
If the student is in MV Calc now, I'd imagine they'd be able to meet one of the criteria above. Unless the school is just trying to boost their proficiency rates for mdreportcard.
But either way, if what the OP is saying is accurate, there is no reason why their student needs to retake the Algebra 1 MCAP test and probably never had to take it in the first place.