Self-employed taxpayers in Maryland owe quarterly estimates to both the IRS and Comptroller of Maryland. The state's top marginal rate sits at 6.5% across a progressive bracket structure. Missing the safe harbor compounds penalties on top of the underlying tax.
Maryland uses a progressive bracket system on top of federal tax. For single filers in 2026:
| Income (single filer) | Marginal rate |
|---|---|
| $0 – $1,000 | 2.00% |
| $1,000 – $2,000 | 3.00% |
| $2,000 – $3,000 | 4.00% |
| $3,000 – $100,000 | 4.75% |
| $100,000 – $125,000 | 5.00% |
| $125,000 – $150,000 | 5.25% |
| $150,000 – $250,000 | 5.50% |
| $250,000 – $500,000 | 5.75% |
| $500,000 – $1,000,000 | 6.25% |
| $1,000,000+ | 6.50% |
Federal estimated tax due dates (April 15, June 15, September 15, 2026, and January 15, 2027) apply to your Maryland state estimated payments as well — most states piggyback on the federal schedule. Pay Maryland taxes through the Comptroller of Maryland's online portal: www.marylandtaxes.gov. You can also mail Form 502DEP with a check.
Federal and state estimated tax safe harbors work in parallel for Maryland freelancers. Hit the federal safe harbor (90% of current-year federal tax OR 100% of prior-year federal tax — 110% if your prior-year AGI exceeded $150,000) and you avoid the IRS underpayment penalty on Form 2210.
For Maryland state estimated taxes, most filers can match the federal safe harbor approach by paying 100% of last year's Maryland tax in four equal quarterly installments. Maryland's underpayment penalty is calculated on the state's equivalent of Form 2210 — the Comptroller can assess interest plus a flat penalty on the under-paid amount.
Practical advice for Maryland self-employed taxpayers: pay both federal and state estimates on the same quarterly schedule (April 15, June 15, September 15, January 15). File your federal payment via IRS Direct Pay and your state payment via Comptroller of Maryland. Keep records of every payment — both agencies can request proof if the safe-harbor math is challenged later.
Four practical Maryland filing details that bite first-time filers:
Maryland is one of two states (with NY) where county-level income tax 'piggybacks' on the state return. Local rates range from 2.25% (Worcester) to 3.20% (Montgomery, Howard, Prince George's). Your county of residence determines the local rate.
Five recurring mistakes the Maryland DOR sees from self-employed filers: