Reviewed for current 2026 law
Massachusetts Child Support Arrears Calculator 2026
Model the DOR monthly interest charge while keeping the separate penalty and eligibility rules visible.
Reviewed by SupportDecode Editorial Team Page content reviewed Sources Methodology Update log
arrears calculator
Estimated arrears with interest: $5,003.00
Interest of $3.00 at 0.06% compound per year (830 CMR 119A.6.1).
| Line item | Amount |
|---|---|
| Arrears principal830 CMR 119A.6.1, Assessment of Interest and Penalties on Past-Due Child Support (Massachusetts Department of Revenue) | $5,000.00 |
| Interest at 0.06% per year, compounded monthly, for 12 month(s) (830 CMR 119A.6.1)DOR assesses interest at 0.5% monthly in qualifying full-service Massachusetts cases with more than $500 past due, unless the required minimum monthly payment was made. A separate 0.5% monthly penalty can also apply and is not included in this interest-only estimate.830 CMR 119A.6.1, Assessment of Interest and Penalties on Past-Due Child Support (Massachusetts Department of Revenue) | $3.00 |
| Arrears principal plus interest830 CMR 119A.6.1, Assessment of Interest and Penalties on Past-Due Child Support (Massachusetts Department of Revenue) | $5,003.00 |
Assumptions
- Accrual period expressed as 12 month(s); partial months prorate.
- Compounding applied monthly at one-twelfth of the annual rate.
Estimate only. The court or state agency calculation controls.
Massachusetts arrears interest under 830 CMR 119A.6.1; rules last reviewed 2026-08-09.
Interest and penalty are separate charges
830 CMR 119A.6.1 authorizes interest at 0.5 percent on the last day of a qualifying month.
A separate 0.5 percent monthly penalty can apply. This calculator models interest only so it does not disguise that second charge as interest.
DOR generally assesses these amounts where more than $500 is past due in a full-service Massachusetts case and the required minimum payment was not made.
Start with the DOR ledger
Enter principal and elapsed time only after confirming the account is subject to Massachusetts assessment rules.
Add no guessed penalty to the interest result; obtain the agency payoff for a collectible balance.
What this estimate includes
- Monthly 0.5% interest model
- Compounding-period disclosure
What it leaves out
- The separate penalty
- Payment history
- Eligibility and official payoff
Massachusetts arrears calculator FAQs
What interest rate does Massachusetts use?
DOR regulations state 0.5 percent per month for qualifying past-due support.
Is there also a penalty?
Potentially. The regulation separately provides a 0.5 percent monthly penalty; this interest calculator excludes it.
Does every overdue dollar get charged?
No. Service status, the $500 balance threshold, and required minimum payment rules matter.
Does this include payments?
No. Use the official transaction history for payment allocation.
Does it apply to another state order?
Massachusetts applies the issuing state interest rule to an out-of-state order.
Is this a payoff quote?
No. Only DOR or the controlling court ledger can provide that.
Official sources
Official sources last verified: .
- 830 CMR 119A.6.1, Assessment of Interest and Penalties on Past-Due Child Support
Massachusetts Department of Revenue Last checked
Changelog: page reviewed . Material changes appear in the update log.