A new job is usually a raise, and yet the first three months are often tighter than the last three at the old one. The gap between the final paycheck and the first new one, the benefits that reset, the sign-on that's really a loan, the vests that don't come with you — each is small, and together they're a month of cash. This guide plans them so the raise shows up on schedule.
1Map the gap between the last check and the first
Old job pays out on its schedule; new job's first check can be three to five weeks after the start date, and a first check is sometimes partial. Write the dates down: last check, start date, first full check. The gap is often four to six weeks of pay. Fund it in advance as a sinking fund — or, if there's a payout of unused PTO, that often covers it. Check the pay period at the new job; biweekly and semimonthly land differently across a month.
2Treat the sign-on as a loan until the clawback expires
A sign-on bonus is taxed as supplemental wages — plan on keeping 60–70% — and most come with a clawback: leave within twelve months and you repay it, sometimes gross. Until the clawback window closes, the after-tax sign-on belongs in a savings account, not in a goal. After it closes, it's a lump like any other.
3Value what you're walking away from
Unvested RSUs, an unvested 401(k) match, a bonus that pays in March if you're still there in March. The comp comparison calculator lays two offers side by side over four years, vesting included — the honest number is often closer than the headline salary suggests. If a large vest is 60 days out, the start date is worth negotiating.
4Plan the resets
Things that start over: insurance deductibles and out-of-pocket maximums (a mid-year switch can mean paying two deductibles), the 401(k) match — often with a waiting period and a new vesting schedule, PTO accrual, HSA and FSA elections. Two things that don't reset: the annual 401(k) contribution limit is per person, not per employer, so contributions at the old job count; and the Social Security wage base — a new employer withholds from zero, which can mean over-withholding you'll get back at filing.
5Move the old 401(k) deliberately
Roll it to an IRA or the new plan, or leave it if the old plan is good and the balance is over the plan's minimum. Never cash it out — tax plus a 10% penalty under 59½. A direct rollover (plan to plan, never through your bank account) avoids the withholding trap. Put a date on it: old 401(k)s left "for now" are the most common lost money there is.
6Re-plan on the first full paycheck, not the offer letter
The offer says $140,000; the first full check says what you actually take home after the new state, the new benefits and the new 401(k) percentage. Re-size the goals from that number. The raise usually arrives — a month or two later than the excitement, once the gap is funded and the resets are behind you.
The plan, in Allocate
You'd say: "New job starts April 6, $140k, $15k sign-on. Old job's last check is March 27, first new check around May 1." Allo-Bot proposes:
- Gap: five weeks between checks; covered by the PTO payout (~$3,100) plus $1,400 from the sinking fund. No goals pause.
- Sign-on: ~$9,900 after tax, held in savings until the clawback ends next April; then re-assigned.
- Left behind: two RSU vests (~$11,000) and $2,400 of unvested match — noted in the plan so the comparison stays honest.
- Resets: new deductible from April; HSA election set; 401(k) restarts at 8% after the 60-day wait, with the year's earlier contributions counted toward the limit.
- Old 401(k): direct rollover to the IRA, due by June 30; a reminder in the brief.
- Re-plan: on the first full check (~May 15), goals re-sized from actual take-home.
Each item is staged; approve the ones you want and edit the rest in plain words — "keep the old 401(k) where it is" — and the plan updates.
Frequently asked questions
How much should I have saved before changing jobs?
Enough to cover the gap between the last check and the first full one — usually four to six weeks of essentials — on top of an intact emergency fund. A PTO payout often covers the gap; if not, fund it in advance.
Is a sign-on bonus taxed differently?
It's supplemental wages: 22% federal withholding (2026) plus FICA and state, so expect to keep 60–70%. And check the clawback — if you leave within the window you may repay the gross amount, so keep the after-tax sign-on in savings until the window closes.
What happens to my 401(k) when I leave?
The money you contributed is yours; the employer match depends on the plan's vesting schedule. Roll it directly to an IRA or the new plan, or leave it if the old plan is good. Don't cash it out — the tax and the 10% penalty under 59½ are the most expensive way to move money.
This guide is educational and uses invented numbers — not investment, tax or legal advice. Your income, taxes and goals are your own; talk to a qualified professional about your situation.