I don’t have enough funds in my HSA/FSA accounts to reimburse the entire purchase price of BrainHQ. Can I still use Truemed?

Yes. You can submit for partial reimbursement. For example: if you purchase an annual subscription to BrainHQ for $96 but only have $60 in your account, you can reimburse $60 of your purchase with your tax-free funds (with the remaining $34 paid for as normal).