Which type of maintenance can be paid in installments and is generally non-modifiable?

Lump sum maintenance is typically paid in installments and is generally non-modifiable. This type of maintenance is agreed upon for a specific total amount that can be paid out over time in installments rather than as a single payment. Once the lump sum is established, it cannot be changed regardless of changes in circumstances for either party, meaning the obligated spouse cannot modify the payment amount or duration later on.

In contrast, permanent maintenance is ongoing support intended to last indefinitely and can be subject to modification. Durational maintenance, while it has a specific duration, may also be modified based on circumstances. Reimbursement spousal support concerns repayment for expenditures made for the other spouse's education or training and is typically not structured as ongoing payments; instead, it focuses on compensating for costs incurred in support of a spouse’s advancement. Thus, lump sum maintenance stands out for its specific characteristics of installment payment and non-modifiability, making it the correct choice.