Four refundable tax credits are worth $15,328 a year here, and the model leaves them out by default
The calculator and every finding on this site compute net income on a withholding basis: federal income tax, Massachusetts income tax, and Social Security and Medicare, the same formula for both parents, no filing status, no dependents, no credits. That basis is reproducible from a published table by anyone. It also understates a low-income parent’s real spendable income, because it leaves out credits that pay out in cash. This page states what those credits are worth at the recipient’s income in the worked example, $29,640 a year, three children, two of them under 13, with a source for each figure.
The four credits, at one income
| Credit | Value | Cutoff | Source |
|---|---|---|---|
| Federal Earned Income Tax Credit | $7,020 | Zero above $62,974 with three qualifying children | IRS Rev. Proc. 2025-32 § 3.06(1) |
| Federal Child Tax Credit, refundable part | $4,620 | Needs earned income; shrinks above $200,000, reaches zero at $332,000 | IRC §§ 24(b), 24(h); Rev. Proc. 2025-32 § 3.05 |
| Massachusetts Earned Income Tax Credit | $2,808 | 40% of the federal credit, so it disappears at the same income | M.G.L. c. 62 § 6(h) |
| Massachusetts Child and Family Tax Credit | $880 | $440 per dependent under 13, two of the three children here | M.G.L. c. 62 § 6(x) |
| Total | $15,328 |
Against $3,808 of federal income tax, Massachusetts income tax, and FICA owed at that same income.
Re-derived from model/net_position.py for this
page: _federal_eitc(), refundable_credits(), and
ma_refundable_credits().
What this page is not
Every figure above depends on which parent claims which child. The federal credit follows the parent the children lived with more than half the year regardless of any agreement, except the Child Tax Credit, which a signed release can move to the other parent for a year. Massachusetts's credits follow the same split. CJ-D 304, the Worksheet, has no field that records who claims whom, so no figure that depends on it can be reproduced from the form alone.
No number in any letter this project writes, and no figure on any finding page, in the comments, or in any chart uses anything from this table. Those are all held to the withholding basis described above, so a reader can rebuild them from published tables without knowing anything about either parent's tax return. The one place these credits are counted is the calculator on the home page, which counts them by default and says so; switch it to "Leave them out" to see the basis every other page uses.
See it with credits counted
The calculator on the home page has a “Refundable tax credits” control. “Count them” is the default there, because these are real money a low-income household receives and leaving them out understates it. “Leave them out” switches to the withholding basis, which is what every other page on this site and every figure in the comments uses. Counting them applies the four credits above under the statutory rule: head-of-household status and both Earned Income Tax Credits stay with whichever parent has the children more of the time, every year, and cannot be moved by agreement. Only the Child Tax Credit can move, by a signed release. At equal parenting time, the calculator averages a year each parent claims it; at primary custody, nothing moves, because the custodial parent already holds all four credits.
Check it yourself
Every figure above is computed by a function you can call directly.