Create a new account with the Underdog promo code TOPACTION to get access to a $50 welcome bonus. Simply submit a $5 lineup using college basketball picks Friday, March 27, 2026, and you’ll receive $50 in fantasy bonus entries—regardless of whether your entry wins or loses.
To activate the promotion, enter the Underdog promo code TOPACTION during registration and create your $5 lineup today. This limited-time promotion provides an elite boost for March Madness DFS contests for college basketball or any other sport.
Underdog continues to rank among the top DFS sites by offering multi-sport lineup options, including picks from a wide range of college basketball contests. With March Madness and the Sweet 16 underway, it’s an ideal time to jump in and build a CBB DFS lineup.
This welcome bonus is available in the following states: AL, AK, AR, CA, DC, FL, GA, IL, IN, KS, ME, MS, MN, NE, NM, NC, ND, OK, OR, RI, SC, SD, TX, VT, VA, UT, WI, and WY.
Use Underdog Promo Code TOPACTION on College Basketball DFS Lineup
Right now, new users can enter the Underdog promo code TOPACTION to secure a $50 welcome bonus for March Madness Sweet 16 games. DFS expert Chris Ilenstine highlights why this stands out as one of the best college basketball DFS promos currently available.
“If you’re building college basketball DFS lineups in March, there’s no reason to pass on the $50 bonus with code TOPACTION. It’s strong value that immediately increases your lineup’s upside.”
To create your lineup, choose “Higher” or “Lower” for each player projection. Once you include three or more picks, you’ll select between a Standard or Flex entry. Standard lineups offer the highest potential payout but require every selection to hit, while Flex entries provide a safety net by allowing one miss, though with a reduced payout.
For a starting point, check out my college basketball DFS lineup for Friday’s March Madness Sweet 16 slate on March 27.
| Player | Team | Pick |
|---|---|---|
| Cameron Boozer | Duke Blue Devils | Higher Than 22.5 Points |
| Bryce Hopkins | St. John's Red Storm | Lower Than 12.5 Points |
| Yaxel Lendeborg | Michigan Wolverings | Higher Than 16.5 Points |
How to Sign Up for Underdog: Friday, March 27, 2026
Follow these steps to use the Underdog promo code TOPACTION and get started with your first lineup:
- Download the app using the Underdog promo code TOPACTION link or module on this page.
- Set up your account by creating a username and password.
- Enter your email, date of birth, and required personal details.
- Apply the Underdog promo code TOPACTION to activate the Play $5, Get $50 bonus offer.
- Accept the Terms of Use and confirm your eligibility (18+ in most states, 19+ in AL/NE, 21+ in MA/AZ).
- Complete registration by selecting “Sign Up”.
- Deposit at least $10 to fund your account.
- Build your first lineup using college basketball picks or any available sport.
Must be 18+ (19+ in AL, NE; 19+ in CO for some games; 21+ in AZ, MA, and VA) and present in a state where Underdog Fantasy operates. Terms apply. Offer not valid in MD, MI, NJ, NY, OH, and PA. Concerned with your play? Call 1-800-MY-RESET or 1-800-GAMBLER or visit www.ncpgambling.org; AZ: 1-800-NEXT-STEP (1-800-639-8783) or text NEXT-STEP to 53342; NY: Call the 24/7 HOPEline at 1-877-8-HOPENY or Text HOPENY (467369).
